Published for SISSA by Springer
Received: March 27, 2013
Accepted: May 7, 2013 Published: May 20, 2013
JHEP05(2013)097
Measurement of D production in deep inelastic scattering at HERA
The ZEUS collaboration
E-mail: mailto:[email protected]
Web End [email protected]
Abstract: The production of D mesons in deep inelastic ep scattering has been measured for exchanged photon virtualities 5 < Q2 < 1000 GeV2, using an integrated luminosity of 363 pb1 with the ZEUS detector at HERA. Dierential cross sections have been measured and compared to next-to-leading-order QCD calculations. The cross-sections are used to extract the charm contribution to the proton structure functions, expressed in terms of the reduced charm cross section, ccred. Theoretical calculations based on ts to inclusive HERA data are compared to the results.
Keywords: Lepton-Nucleon Scattering, Charm physics
ArXiv ePrint: 1303.6578
Open Access doi:http://dx.doi.org/10.1007/JHEP05(2013)097
Web End =10.1007/JHEP05(2013)097
Contents
1 Introduction 1
2 Experimental set-up 2
3 QCD calculations 3
4 Monte Carlo samples 4
5 Event selection and signal extraction 45.1 DIS event selection 45.2 Selection of D+ candidates and signal extraction 5
6 Cross-section extraction 6
7 Systematic uncertainties 7
8 Results 9
9 Charm reduced cross sections 10
10 Conclusions 11
The ZEUS collaboration 33
1 Introduction
The measurement of charm production in deep inelastic ep scattering (DIS) is a powerful tool to study quantum chromodynamics (QCD) and the proton structure. In leading-order QCD, charm production occurs through the boson-gluon fusion (BGF) process g
cc, which is directly sensitive to the gluon content of the proton. Dierent approaches to the calculation of the heavy-quark contribution to the proton structure functions are currently used in global analyses of parton density functions (PDFs) [14]. Comparisons to measurements of charm production in DIS provide direct tests of these approaches [5]. It has also been shown recently that a combined analysis of charm production and inclusive DIS data can provide a competitive determination of the charm-quark mass [57].
Several measurements of charm production in DIS have been performed at HERA, exploiting reconstructed D0 [8], D [810] and D [1117] mesons, semi-leptonic decays [18], and inclusive lifetime methods [19, 20] to tag charm. In this paper, a new high-statistics measurement of D production via the reaction
e(k) p(P ) e(k) D(pD) X
1
JHEP05(2013)097
is presented. The symbols in parenthesis represent the four-momenta of the incoming (k) and outgoing electron (k), of the incoming proton (P ), and of the produced D (pD). The measurement is performed for photon virtualities, Q2 q2 = (kk)2, in the range 5 < Q2 < 1000 GeV2 and for inelasticities, y (P q)/(P k), in the range 0.02 < y < 0.7.
The D+ mesons1 were reconstructed through the decay D+ D0+ with D0
K+. Dierential cross sections are presented as a function of Q2, y, the Bjorken-x variable, and of the fraction of the exchanged-photon energy transferred to the D+ meson in the proton rest frame, zD (P pD)/(P q), as well as of the D+ pseudorapidity,
D, and the transverse momentum, pDT, in the laboratory frame.2
Double-dierential cross sections in Q2 and y are presented and used to extract the charm contribution to the proton structure functions in the form of the reduced charm cross section, ccred. Previous measurements and theoretical calculations are compared to the results.
2 Experimental set-up
The measurement was based on ep collisions collected with the ZEUS detector at HERA in the period 20042007 with an electron3 beam energy, Ee, of 27.5 GeV and a proton beam energy, Ep, of 920 GeV, corresponding to a centre-of-mass energy s = 318 GeV. The corresponding integrated luminosity, L = 363 7 pb1, is four times larger than that
used for the previous ZEUS measurement [11].
A detailed description of the ZEUS detector can be found elsewhere [21]. In the kinematic range of the analysis, charged particles were tracked in the central tracking detector (CTD) [2224] and in the microvertex detector (MVD) [25]. These components operated in a magnetic eld of 1.43 T provided by a thin superconducting solenoid. The CTD consisted of 72 cylindrical drift chamber layers, organised in nine superlayers covering the polar-angle region 15 < < 164. The MVD consisted of a barrel (BMVD) and a forward (FMVD) section with three cylindrical layers and four vertical planes of single-sided silicon strip sensors in the BMVD and FMVD respectively. The BMVD provided polar-angle coverage for tracks crossing the three layers from 30 to 150. The FMVD extended the polar-angle coverage in the forward region down to 7. For CTD-MVD tracks that pass through all nine CTD superlayers, the momentum resolution was (pT )/pT =
0.0029pT 0.0081 0.0012/pT , with pT in GeV.
The high-resolution uranium-scintillator calorimeter (CAL) [2629] consisted of three parts: the forward, the barrel, and the rear (RCAL) calorimeters. Under test-beam conditions, the CAL single-particle relative energy resolutions were (E)/E = 0.18/E for electrons and (E)/E = 0.35/E for hadrons, with E in GeV. The energy of electrons
1Hereafter the charge conjugated states are implied.
2The ZEUS coordinate system is a right-handed Cartesian system, with the Z axis pointing in the proton beam direction, referred to as the forward direction, and the X axis pointing towards the centre of HERA. The coordinate origin is at the nominal interaction point. The pseudorapidity is dened as = ln[notdef][notdef]tan
where the polar angle, , is measured with respect to the proton beam direction.
3Hereafter electron refers to both electrons and positrons unless otherwise stated.
2
JHEP05(2013)097
2
,
hitting the RCAL was corrected for the presence of dead material using the rear presampler detector [30] and the small angle rear tracking detector (SRTD) [31].
The luminosity was measured using the Bethe-Heitler reaction ep e p by a lumi
nosity detector which consisted of two independent systems: a lead-scintillator calorimeter [3234] and a magnetic spectrometer [35].
3 QCD calculations
Cross sections for heavy-quark production in DIS were calculated at next-to-leading order (NLO), i.e. O( 2s), in the xed-avour-number scheme (FFNS), in which only light avours and gluons are present as partons in the proton and heavy quarks are produced in the hard interaction [36]. The program Hvqdis [37, 38] was used to compute single- and double-dierential D+ cross sections.
The parameters used as input to Hvqdis are listed below, together with the variations used to evaluate the uncertainty on the theoretical prediction:
charm-quark pole mass: mc = 1.50 0.15 GeV;
renormalisation (R) and factorisation (F ) scales: R = F =
independently up and down by a factor two;
strong coupling constant in the three-avour FFNS: nf=3s(MZ) = 0.105 0.002;
the PDFs and their uncertainties, taken from a FFNS variant [5] of the HERA-
PDF1.0 t [39]. The central PDF set was obtained from a t performed using the same values of mc, R, F and s as used in the Hvqdis program. For each variation of these parameters in Hvqdis, a dierent PDF set was used, in which the parameters were varied consistently.
The NLO calculation provided dierential cross sections for charm quarks. The fragmentation model described in a previous publication [5] was used to compare to the measured D+ cross sections. This model is based on the fragmentation function of Kartvelishvili et al. [40], controlled by the parameter K, to describe the fraction of the charm momentum transferred to the D+ mesons. It also implements a transverse fragmentation component by assigning to the D+ meson a transverse momentum, kT , with respect to the charm-quark direction. The uncertainty on the fragmentation model was estimated by varying K and the average kT according to the original prescription [5]. The fraction of charm quarks hadronising into D+ mesons was set to f(c D+) = 0.2287 0.0056 [41].
For the inclusive cross section, theoretical predictions were also obtained in the generalised-mass variable-avour-number scheme (GM-VFNS). In this scheme, charm quarks are treated as massive particles for Q2 m2c and as massless partons for Q2 m2c,
interpolating in the intermediate region [4244]. The calculation was performed using the Roberts-Thorne (RT) standard [45, 46] variant of the GM-VFNS at NLO, corresponding to O( 2s) for the Q2 m2c part and to O( s) for the Q2 m2c part. PDFs obtained from
the HERAPDF1.5 [47, 48] t to inclusive HERA data were used. The central prediction
3
JHEP05(2013)097
pQ2 + 4m2c, varied
was obtained for mc = 1.5 GeV. To evaluate the theoretical uncertainty, the calculation was repeated varying the PDF set and its parameters according to the systematic variations associated with the HERAPDF1.5 t. The dominant source of uncertainty was the charm-quark mass, which was varied in the range 1.35 < mc < 1.65 GeV.
4 Monte Carlo samples
Monte Carlo (MC) samples were used to calculate the experimental acceptance and to estimate the background contamination. MC samples of charm and beauty DIS events were generated using Rapgap 3.00 [49]. The main sample consisted of events generated according to the LO BGF process. Radiative QED corrections to the BGF process were included through Heracles 4.6 [50]. Additional Rapgap samples were generated for diractive charm production and for the resolved-photon processes gg cc and cg
cg, in which one of the incoming partons originates from the exchanged photon. Charm photoproduction was simulated using Pythia 6.2 [51].
Both Rapgap and Pythia use parton showers to simulate higher-order QCD eects and use the Pythia/Jetset hadronisation model [51]. All samples were generated using the CTEQ5L [52] proton PDFs and, for resolved-photon processes, the GRV-G LO [53] photon PDFs. The diractive samples were generated using the H1 t 2 [54] diractive PDFs. The heavy-quark masses were set to mc = 1.5 GeV and mb = 4.75 GeV. Masses, widths and lifetimes of charmed mesons were taken from PDG2010 [55].
The MC samples correspond to about four times the luminosity of the data and were passed through a full simulation of the ZEUS detector based on Geant 3.21 [56]. They were then subjected to the same trigger criteria and reconstructed with the same programs as used for the data.
5 Event selection and signal extraction
5.1 DIS event selection
A three-level trigger system was used to select DIS events online [21, 57, 58] by requiring electromagnetic energy deposits in the CAL at the rst level and applying loose DIS selection criteria at the second and third levels.
Oine, the hadronic system was reconstructed using energy-ow objects (EFOs) [59] which combine tracking and calorimeter information. The electron was identied using a neural-network algorithm [60]. The kinematical variables Q2, y, and x were reconstructed using the method [61]. The variable zD was reconstructed according to zD = (ED pDZ)/(2EeyJB), where yJB is the inelasticity reconstructed with the Jacquet-
Blondel method [62] and ED and pDZ are the D+ energy and longitudinal momentum, respectively.
The following criteria were applied to select DIS events [63]:
Ee
> 10 GeV, where Ee is the energy of the scattered electron;
4
JHEP05(2013)097
ye < 0.7, yJB > 0.02, where ye is the inelasticity reconstructed from the scattered
electron;
40 <EPZ < 70 GeV, where EPZ is the global dierence of energy and longitudinal
momentum, obtained by summing the electron and the hadronic nal state, which is expected to be 2Ee = 55 GeV for fully contained events;
the Z position of the primary vertex, Zvtx, was required to be in the range |Zvtx| <
30 cm;
the impact point of the scattered electron on the RCAL was required to lie outside a
square region around the beam-pipe hole: |Xe| > 15 cm or |Ye| > 15 cm;
5 < Q2 < 1000 GeV2, where Q2 is reconstructed with the method.
5.2 Selection of D+ candidates and signal extraction
The D+ mesons were identied using the decay channel D+ D0+s with the subsequent
decay D0 K+, where +s refers to a low-momentum (slow) pion accompanying
the D0.
Tracks from the D+ decay products were required to have at least one hit in the MVD or in the inner superlayer of the CTD and to reach at least the third superlayer. Tracks with opposite charge and with transverse momentum pK,T > 0.4 GeV were combined in pairs to form D0 candidates. The track parameters were improved by tting the two tracks to a common vertex. Pairs incompatible with coming from the same decay were removed by requiring a distance of closest approach of the two tracks of less than 1 mm, and the ~2 of the two-track vertex t smaller than 20 for one degree of freedom. The tracks were alternately assigned the kaon and pion mass and the invariant mass of the pair, M(K), was calculated. Each additional track, with charge opposite to that of the kaon track and a transverse momentum psT > 0.12 GeV, was assigned the pion mass and combined with the D0 candidate to form a D+ candidate. The s track was then tted to the primary vertex of the event, obtained exploiting the other tracks reconstructed in the event and the constraint from the average position of the interaction point [8]. The mass dierence M M(Ks) M(K) was used to extract the D+ signal. The D+
candidates were required to have 1.80 < M(K) < 1.92 GeV, 143.2 < M < 147.7 MeV, 1.5 < pDT < 20 GeV and | D| < 1.5.
The distribution of M(K) for D+ candidates, without the requirement on M(K), is shown in gure 1. Also shown is the distribution of wrong-sign (WS) candidates, obtained by combining two tracks with the same charge. The WS distribution provides an estimate of combinatorial backgrounds. A clear peak at the D0 mass is visible in the correct-sign (CS) distribution. The excess of CS candidates at masses below the D0 peak is due to partly-reconstructed D0 decays, mostly D0 K+0.
The distribution of M for D+ candidates, without the requirement on M, is shown in gure 2. A clear D+ peak is seen. The D+ signal was extracted by subtracting the background estimate from the number of candidates in the signal window 143.2 < M <
5
JHEP05(2013)097
147.7 MeV. The background estimate was obtained by tting simultaneously the CS and WS distributions to the parametrisation
WS : fws( ) = A B eC ,
CS : fcs( ) = D fws( ),
where A, B, C, D are free parameters of the t [64] and = M m
+ . The t was
performed in the region M < 168 MeV. The region with a possible signal contribution, 140 < M < 150 MeV, was removed from the t to the CS distribution. The parameter D, which represents the normalisation of the CS background with respect to the WS distribution, is slightly larger than unity, D = 1.0210.005. This is consistent with the MC
estimation of the additional combinatorial background component in the CS distribution due to real D0 K decays associated with a random track to form a CS D+ candidate.
The total signal is NDdata = 12893 185.
The amount of signal lost due to the tails of the D0 mass peak leaking outside the M(K) window was estimated by enlarging the mass window to 1.7 < M(K) < 2.0 GeV. The fraction of additional D+ found within the enlarged window was 13%, including the contribution from partly reconstructed D0. This fraction, as well as its dependence on pDT and D and on the width of the M(K) window, was found to be well reproduced by MC.
The signal in the tails of the D+ peak outside the M window was estimated similarly, enlarging the signal window to 140 < M < 150 MeV. The fraction of additional D+ was
6% on average, with a dependence on the transverse momentum of the slow pion, due to the momentum and angular resolution degrading at low pST. This eect is not completely reproduced by the MC. An acceptance correction [63] dependent on psT was then applied, ranging from 10% at psT = 0.12 GeV to 1% at large psT.
6 Cross-section extraction
The dierential cross sections, dvis/d, for producing a D+ in the visible phase space 1.5 < pDT < 20 GeV, | D| < 1.5, 5 < Q2 < 1000 GeV2 and 0.02 < y < 0.7 was obtained as dvis
d =
where NDdata is the signal extracted in a bin of a given variable , ND p is the photoproduction background, is the bin size, A is the acceptance, BR = B(D+ D0+) B(D0
K+) = 0.0263 0.0004 [65] is the branching ratio, L is the integrated luminosity and
Cr is the QED radiative correction.
The background from charm photoproduction (Q2 < 1.5 GeV2) was evaluated using the photoproduction MC sample, normalised to the luminosity using the cross sections previously measured by ZEUS [66, 67].
The acceptance, A, was calculated as the ratio between the number of reconstructed
and generated D+ in the bin, using a signal MC based on a mix of charm and beauty production. The beauty MC was normalised to 1.6 times the cross section given by Rapgap,
6
JHEP05(2013)097
NDdata ND p A BR L
Cr,
consistent with ZEUS measurements [18, 6870]. The charm MC contained non-diractive and diractive components, summed according to the relative cross sections as given by Rapgap. The normalisation of the charm MC was adjusted such that the sum of all the MC components reproduced the number of D+ mesons in the data. Resolved-photon processes were not included. They were only used for systematic checks. The D and pDT distributions of the charm MC were reweighted [63] to improve the agreement with data, with the pDT weights dependent on Q2.
The acceptance as determined by the MC was corrected to account for imperfections in the simulation of the trigger and track-reconstruction eciencies. One of the main sources of track-reconstruction ineciency for charged pions and kaons were hadronic interactions in the material between the interaction point and the CTD. This eect was studied using special tracks from ep e0 with 0 + events, reconstructed from MVD hit
information alone [71]. For these tracks, an extension into the CTD was searched for. In addition, the pT dependence of the tracking eciency was studied by exploiting the isotropic angular distribution of pions from K0S decays. The studies showed that the MC slightly underestimated the eect of nuclear interactions. For central pions with pT 1 GeV, the
track-reconstruction ineciency due to hadronic interactions was measured to be (7 1)%
while the MC predicted 5%. The track-eciency correction was applied as a function of and pT of each track. For pT > 1.5 GeV, no correction was necessary.
The acceptance ranges from A 10% in the lowest pDT and Q2 bins to A 45% in the
highest pDT and Q2 bins. Figure 3 shows NDdata/ for = pDT, D , Q2, y and zD. The sum of the dierent MC samples is compared to the data. The agreement is satisfactory.
The cross sections were corrected to the QED Born level, using a running coupling constant em(Q2), such that they can be compared directly to the QCD predictions from the Hvqdis program. The radiative corrections were obtained as Cr = Bornvis/radvis, where Bornvis is the Rapgap cross section with the QED corrections turned o but keeping em running and radvis is the Rapgap cross section with the full QED corrections, as in the standard MC samples.
7 Systematic uncertainties
The experimental systematic uncertainties are listed below [63], with their typical eect on the measured cross sections is given in parenthesis:
1 energy-scale uncertainty on the hadronic system of 2% (1%, up to 10% at low y); 2 electron energy-scale uncertainty of 1% [72] (1%, up to 7% at low y);
3 alignment uncertainty on the electron impact point on the RCAL, estimated by varying the cut on the electron position in the MC by 2 mm separately for the Xe and
Ye coordinates [72] (7% at low Q2 and low y, negligible at large Q2); 4 uncertainty on the position of the electron impact point on the RCAL due to imperfections in the simulation of the shower shape and of the detector resolution, estimated by loosening the cut on the electron position by 1 cm (|Xe| > 14 cm or
7
JHEP05(2013)097
|Ye| > 14 cm) both in data and in MC (up to 10% at low y and low Q2, negligible
at large Q2);
5 uncertainty on the background shape in M, estimated by replacing the function fcs( ) by fcs( ) = A
2 (+0.3%); 6 a further uncertainty on the background shape, evaluated by reducing the t range from M < 168 MeV to M < 165 MeV (+0.5%);
7 uncertainty on the amount of signal outside the M window, evaluated by varying the pST-dependent correction by its uncertainty (1.5%, up to 3% at low pT );
8 uncertainty on the amount of signal outside the M(K) window, estimated by comparing data and MC in an enlarged mass range (+2%);
9 uncertainty on the track eciency, evaluated by varying the track eciency correction applied to MC by the associated uncertainty (2%);
10 uncertainty on the trigger eciency, evaluated using independent triggers (0.5%); 11 statistical uncertainty on the calculation of the acceptance (1%);
12 uncertainty on the normalisation of the beauty MC of 50% to cover the range
allowed by ZEUS measurements [68, 70] (0.3%); 13 uncertainty on the normalisation of the photoproduction MC of 100% (up to 3%
at high y, but negligible elsewhere);
14 uncertainty on the normalisation of the diractive charm MC of 50% to cover the
range allowed by data-MC comparison and by previous ZEUS results [73] (up to
4.5% at low y, but negligible elsewhere);
15 uncertainty due to the resolved-photon component, evaluated by adding the resolved-photon samples to the charm MC normalised according to the generator cross section (+2%);
16 uncertainty on the MC reweighting as a function of pDT and Q2, which was varied by
50% (2%); 17 uncertainty on the MC reweighting as a function of D which was replaced by a MC reweighting as a function of y (from 2% to +3%, depending on y);
18 uncertainty on the integrated luminosity of 1.9%; 19 uncertainty on the branching ratio BR of 1.5%.
All the systematic uncertainties, except the overall normalisations 18 and 19, were added in quadrature to the statistical uncertainties to obtain the total error bars in the gures.
8
2 3 + B + C
1
JHEP05(2013)097
8 Results
Single- and double-dierential cross sections have been measured in the phase space
5 < Q2 < 1000 GeV2; 0.02 < y < 0.7; 1.5 < pDT < 20 GeV; | D| < 1.5.
Dierential cross sections in pDT, D and zD are reported in tables 13 and in gure 4. The cross section decreases steeply with pDT and is almost constant in D. The NLO calculations based on Hvqdis and the Rapgap MC implementing the leading-order BGF process are compared to the data. As the Rapgap MC is based on leading-order matrix elements, it is not expected to estimate the normalisation correctly. Therefore the Rapgap prediction was normalised to the data, scaling it by 1.1, to allow a direct comparison of the shapes. The data are well described by the NLO calculation and by Rapgap with the exception of the shape in zD, which is not well reproduced by the NLO calculation, suggesting possible imperfections in the fragmentation model.
Dierential cross sections in Q2, y and x are reported in tables 46 and in gure 5. The results are reasonably well described by the NLO calculation. The MC predictions reproduce the shapes of the data, except for the high-Q2 tail, where the MC prediction is too high, and for d/dy, where the prediction is too low at low y and too high at large y. These imperfections in the MC are to be expected in the absence of higher-order terms in Rapgap.
Visible cross sections in two-dimensional bins of Q2 and y, vis, are given in table 7. The corresponding bin-averaged double-dierential cross sections are shown in gures 6 and 7. The values of the individual systematic uncertainties on the double-dierential cross sections are given in table 8. Measurements performed in the same phase space by the H1 Collaboration [16, 17], which are the most precise previous measurement of D+
production in DIS, are compared to the present results. The two data sets are in agreement and have similar precision. The double-dierential cross sections are well described by the NLO calculation.
In a previous ZEUS measurement [11], a possible excess in the D+ yield in ep collisions was observed with respect to e+p collisions. The ratio of observed rates, increasing with Q2, was rep/re+p = 1.67 0.21(stat.) for 40 < Q2 < 1000 GeV2. The measurement
was based on a luminosity of 17 (65) pb1 of ep (e+p) collisions. The present measurement is based on an independent data set, consisting of 187 (174) pb1 of ep (e+p) collisions. Figure 8 shows the cross-section ratio as a function of Q2. Only statistical uncertainties are shown since systematic eects mostly cancel in the ratio. No deviation from unity is observed, conrming the original interpretation of the ep excess as a statistical uctuation.
9
JHEP05(2013)097
9 Charm reduced cross sections
The reduced cross section for charm, ccred, and the charm contribution to the proton structure functions, F cc2 and F ccL, are dened as:
d2cc
dx dQ2 =
2 2emxQ4 Y+ ccred(x, Q2, s),
ccred(x, Q2, s) = F cc2(x, Q2)
y2Y+ F ccL(x, Q2),
JHEP05(2013)097
where Y+ = 1 + (1 y)2.
The Hvqdis program was used to extrapolate the measured visible D+ cross sections in bins of y and Q2, vis, to the full phase space:
ccred(x, Q2) =
vis beautyvis[parenrightBig][parenleftBigg]ccred,Hvqdis(x, Q2) vis,Hvqdis
!,
where beautyvis is the beauty contribution as predicted by the Rapgap MC, normalised as discussed in section 6, and ccred,Hvqdis, vis,Hvqdis are the charm reduced and the visible
D+ cross sections, respectively, as given by Hvqdis. The reference values of x and Q2 were chosen close to the average x and Q2 of the bins. The kinematic acceptance of the visible phase space, dened as Aps = vis/(cc 2 f(c D+)), where cc is the charm production total cross section in the y and Q2 bin, ranges from 17% to 64%, depending on the bin.
Following the method used in the previously published combination of ZEUS and H1 results [5], the Hvqdis and fragmentation variations described in section 3 were used to determine the theoretical uncertainty on the extraction of ccred. The scales R and F were varied simultaneously rather than independently as in the theoretical uncertainty for the dierential cross sections. An additional uncertainty originates from the subtracted beauty component that was varied by 50%. The theoretical uncertainties due the extrap
olation on ccred(x, Q2) are given in table 9. The experimental part of the uncertainties on ccred(x, Q2) is dened as the quadratic sum of the statistical and the experimental systematic uncertainties described in section 7.
The results are reported in table 10 and are shown in gure 9. The combined result based on previous H1 and ZEUS charm measurements [5] and a recent ZEUS measurement with D+ mesons [9], not included in the combined results, are also shown. All three measurements are in good agreement. The D measurement has a precision close to that of the combined result in some parts of the phase space. The GM-VFNS calculation, based on the HERAPDF1.5 parton-density t to inclusive HERA data, is compared to the present measurement and shown in gure 10. The uncertainty on the prediction is dominated by the charm-quark mass. The prediction is in good agreement with the data.
10
10 Conclusions
Dierential cross sections for the production of D mesons in DIS have been measured with the ZEUS detector in the kinematic range
5 < Q2 < 1000 GeV2; 0.02 < y < 0.7; 1.5 < pDT < 20 GeV; | D| < 1.5,
using data from an integrated luminosity of 363 pb1. The new data represent one of the most precise measurements of charm production in DIS obtained to date. The data are reasonably well described by NLO QCD calculations and are in agreement with previously published results.
The measurements have been used to extract the reduced cross sections for charm ccred. A GM-VFNS calculation based on a PDF t to inclusive DIS HERA data agrees well with the results. This demonstrates a consistent description of charm and inclusive data within the NLO QCD framework.
Acknowledgments
We appreciate the contributions to the construction and maintenance of the ZEUS detector of many people who are not listed as authors. The HERA machine group and the DESY computing sta are especially acknowledged for their success in providing excellent operation of the collider and the data-analysis environment. We thank the DESY directorate for their strong support and encouragement.
Open Access. This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.
References
[1] S. Kretzer, H. Lai, F. Olness and W. Tung, Cteq6 parton distributions with heavy quark mass e ects, http://dx.doi.org/10.1103/PhysRevD.69.114005
Web End =Phys. Rev. D 69 (2004) 114005 [http://arxiv.org/abs/hep-ph/0307022
Web End =hep-ph/0307022 ] [http://inspirehep.net/search?p=find+J+Phys.Rev.,D69,114005
Web End =INSPIRE ].
[2] A. Martin, W. Stirling, R. Thorne and G. Watt, Parton distributions for the LHC, http://dx.doi.org/10.1140/epjc/s10052-009-1072-5
Web End =Eur. Phys. J. C 63 (2009) 189 [arXiv:0901.0002] [http://inspirehep.net/search?p=find+J+Eur.Phys.J.,C63,189
Web End =INSPIRE ].
[3] S. Alekhin, J. Blumlein, S. Klein and S. Moch, The 3, 4 and 5-avor NNLO Parton from Deep-Inelastic-Scattering Data and at Hadron Colliders, http://dx.doi.org/10.1103/PhysRevD.81.014032
Web End =Phys. Rev. D 81 (2010) 014032 [arXiv:0908.2766] [http://inspirehep.net/search?p=find+J+Phys.Rev.,D81,014032
Web End =INSPIRE ].
[4] R.D. Ball et al., Impact of Heavy Quark Masses on Parton Distributions and LHC Phenomenology, http://dx.doi.org/10.1016/j.nuclphysb.2011.03.021
Web End =Nucl. Phys. B 849 (2011) 296 [arXiv:1101.1300] [http://inspirehep.net/search?p=find+J+Nucl.Phys.,B849,296
Web End =INSPIRE ].
[5] H1, ZEUS collaborations, H. Abramowicz et al., Combination and QCD Analysis of Charm Production Cross section Measurements in Deep-Inelastic ep Scattering at HERA,http://dx.doi.org/10.1140/epjc/s10052-013-2311-3
Web End =Eur. Phys. J. C 73 (2013) 2311 [arXiv:1211.1182] [http://inspirehep.net/search?p=find+J+Eur.Phys.J.,C73,2311
Web End =INSPIRE ].
[6] S. Alekhin and S. Moch, Heavy-quark deep-inelastic scattering with a running mass, http://dx.doi.org/10.1016/j.physletb.2011.04.026
Web End =Phys. Lett. B 699 (2011) 345 [arXiv:1011.5790] [http://inspirehep.net/search?p=find+J+Phys.Lett.,B699,345
Web End =INSPIRE ].
11
JHEP05(2013)097
[7] S. Alekhin, K. Daum, K. Lipka and S. Moch, Determination of the charm-quark mass in the MS-bar scheme using charm production data from deep inelastic scattering at HERA,http://dx.doi.org/10.1016/j.physletb.2012.11.010
Web End =Phys. Lett. B 718 (2012) 550 [arXiv:1209.0436] [http://inspirehep.net/search?p=find+J+Phys.Lett.,B718,550
Web End =INSPIRE ].
[8] ZEUS collaboration, S. Chekanov et al., Measurement of D and D0 production in deep inelastic scattering using a lifetime tag at HERA, http://dx.doi.org/10.1140/epjc/s10052-009-1088-x
Web End =Eur. Phys. J. C 63 (2009) 171 [arXiv:0812.3775] [http://inspirehep.net/search?p=find+J+Eur.Phys.J.,C63,171
Web End =INSPIRE ].
[9] ZEUS collaboration, H. Abramowicz et al., Measurement of D production in deep inelastic ep scattering with the ZEUS detector at HERA, http://dx.doi.org/10.1007/JHEP05(2013)023
Web End =JHEP 05 (2013) 023 [arXiv:1302.5058] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1302.5058
Web End =INSPIRE ].[10] ZEUS collaboration, H. Abramowicz et al., Measurement of D+ and +c production in deep inelastic scattering at HERA, http://dx.doi.org/10.1007/JHEP11(2010)009
Web End =JHEP 11 (2010) 009 [arXiv:1007.1945] [http://inspirehep.net/search?p=find+J+JHEP,1011,009
Web End =INSPIRE ].
[11] ZEUS collaboration, S. Chekanov et al., Measurement of D production in deep inelastic ep scattering at HERA, http://dx.doi.org/10.1103/PhysRevD.69.012004
Web End =Phys. Rev. D 69 (2004) 012004 [http://arxiv.org/abs/hep-ex/0308068
Web End =hep-ex/0308068 ] [http://inspirehep.net/search?p=find+J+Phys.Rev.,D69,012004
Web End =INSPIRE ].
[12] ZEUS collaboration, J. Breitweg et al., D production in deep inelastic scattering at HERA, http://dx.doi.org/10.1016/S0370-2693(97)00847-2
Web End =Phys. Lett. B 407 (1997) 402 [http://arxiv.org/abs/hep-ex/9706009
Web End =hep-ex/9706009 ] [http://inspirehep.net/search?p=find+J+Phys.Lett.,B407,402
Web End =INSPIRE ].
[13] ZEUS collaboration, J. Breitweg et al., Measurement of D production and the charm contribution to F2 in deep inelastic scattering at HERA, http://dx.doi.org/10.1007/s100529900244
Web End =Eur. Phys. J. C 12 (2000) 35 [http://arxiv.org/abs/hep-ex/9908012
Web End =hep-ex/9908012 ] [http://inspirehep.net/search?p=find+J+Eur.Phys.J.,C12,35
Web End =INSPIRE ].
[14] H1 collaboration, C. Adlo et al., Measurement of D meson production and F c2 in deep inelastic scattering at HERA, http://dx.doi.org/10.1016/S0370-2693(02)01195-4
Web End =Phys. Lett. B 528 (2002) 199 [http://arxiv.org/abs/hep-ex/0108039
Web End =hep-ex/0108039 ] [http://inspirehep.net/search?p=find+J+Phys.Lett.,B528,199
Web End =INSPIRE ].
[15] H1 collaboration, A. Aktas et al., Inclusive production of D+, D0, D+s and D mesons in deep inelastic scattering at HERA, http://dx.doi.org/10.1140/epjc/s2004-02069-x
Web End =Eur. Phys. J. C 38 (2005) 447 [http://arxiv.org/abs/hep-ex/0408149
Web End =hep-ex/0408149 ]
[http://inspirehep.net/search?p=find+J+Eur.Phys.J.,C38,447
Web End =INSPIRE ].[16] H1 collaboration, F. Aaron et al., Measurement of the D Meson Production Cross section and F cc2, at High Q2, in ep Scattering at HERA, http://dx.doi.org/10.1016/j.physletb.2010.02.024
Web End =Phys. Lett. B 686 (2010) 91 [arXiv:0911.3989] [http://inspirehep.net/search?p=find+J+Phys.Lett.,B686,91
Web End =INSPIRE ].
[17] H1 collaboration, F. Aaron et al., Measurement of D Meson Production and Determination of F cc2 at low Q2 in Deep-Inelastic Scattering at HERA,
http://dx.doi.org/10.1140/epjc/s10052-011-1769-0
Web End =Eur. Phys. J. C 71 (2011) 1769 [Erratum ibid. C 72 (2012) 2252] [arXiv:1106.1028] [http://inspirehep.net/search?p=find+J+Eur.Phys.J.,C71,1769
Web End =INSPIRE ].[18] ZEUS collaboration, S. Chekanov et al., Measurement of charm and beauty production in deep inelastic ep scattering from decays into muons at HERA, http://dx.doi.org/10.1140/epjc/s10052-009-1193-x
Web End =Eur. Phys. J. C 65 (2010) 65 [arXiv:0904.3487] [http://inspirehep.net/search?p=find+Eur.Phys.J,C65,65
Web End =INSPIRE ].
[19] H1 collaboration, A. Aktas et al., Measurement of F cc2 and F bb2 at low Q2 and x using the H1 vertex detector at HERA, http://dx.doi.org/10.1140/epjc/s2005-02415-6
Web End =Eur. Phys. J. C 45 (2006) 23 [http://arxiv.org/abs/hep-ex/0507081
Web End =hep-ex/0507081 ] [http://inspirehep.net/search?p=find+J+Eur.Phys.J.,C45,23
Web End =INSPIRE ].
[20] H1 collaboration, F. Aaron et al., Measurement of the Charm and Beauty Structure Functions using the H1 Vertex Detector at HERA, http://dx.doi.org/10.1140/epjc/s10052-009-1190-0
Web End =Eur. Phys. J. C 65 (2010) 89 [arXiv:0907.2643] [http://inspirehep.net/search?p=find+J+Eur.Phys.J.,C65,89
Web End =INSPIRE ].
[21] ZEUS collaboration, The ZEUS Detector, U. Holm ed., DESY (1993), unpublished, available on http://www-zeus.desy.de/bluebook/bluebook.html
Web End =http://www-zeus.desy.de/bluebook/bluebook.html .
[22] N. Harnew et al., Vertex Triggering Using Time Di erence Measurements in the ZEUS Central Tracking Detector, http://dx.doi.org/10.1016/0168-9002(89)91096-6
Web End =Nucl. Instrum. Meth. A 279 (1989) 290 [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A279,290
Web End =INSPIRE ].
12
JHEP05(2013)097
[23] B. Foster et al., The performance of the ZEUS central tracking detector z-by-timing electronics in a transputer based data acquisition system,http://dx.doi.org/10.1016/0920-5632(93)90023-Y
Web End =Nucl. Phys. Proc. Suppl. B 32 (1993) 181 .
[24] B. Foster et al., The Design and construction of the ZEUS central tracking detector, http://dx.doi.org/10.1016/0168-9002(94)91313-7
Web End =Nucl. Instrum. Meth. A 338 (1994) 254 [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A338,254
Web End =INSPIRE ].
[25] A. Polini et al., The design and performance of the ZEUS Micro Vertex detector, http://dx.doi.org/10.1016/j.nima.2007.08.167
Web End =Nucl. Instrum. Meth. A 581 (2007) 656 [arXiv:0708.3011] [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A581,656
Web End =INSPIRE ].
[26] M. Derrick et al., Design and construction of the ZEUS barrel calorimeter., http://dx.doi.org/10.1016/0168-9002(91)90094-7
Web End =Nucl. Instrum. Meth. A 309 (1991) 77 [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A309,77
Web End =INSPIRE ].
[27] A. Andresen et al., Construction and beam test of the ZEUS forward and rear calorimeter, http://dx.doi.org/10.1016/0168-9002(91)90095-8
Web End =Nucl. Instrum. Meth. A 309 (1991) 101 [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A309,101
Web End =INSPIRE ].
[28] A. Caldwell et al., Design and implementation of a high precision readout system for the ZEUS calorimeter, http://dx.doi.org/10.1016/0168-9002(92)90413-X
Web End =Nucl. Instrum. Meth. A 321 (1992) 356 [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A321,356
Web End =INSPIRE ].
[29] A. Bernstein et al., Beam tests of the ZEUS barrel calorimeter,
http://dx.doi.org/10.1016/0168-9002(93)91078-2
Web End =Nucl. Instrum. Meth. A 336 (1993) 23 [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A336,23
Web End =INSPIRE ].
[30] A. Bamberger et al., The Presampler for the forward and rear calorimeter in the ZEUS detector, http://dx.doi.org/10.1016/S0168-9002(96)00776-0
Web End =Nucl. Instrum. Meth. A 382 (1996) 419 [http://arxiv.org/abs/hep-ex/9609006
Web End =hep-ex/9609006 ] [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A382,419
Web End =INSPIRE ].
[31] A. Bamberger et al., The Small angle rear tracking detector of ZEUS, http://dx.doi.org/10.1016/S0168-9002(97)01029-2
Web End =Nucl. Instrum. Meth. A 401 (1997) 63 [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A401,63
Web End =INSPIRE ].
[32] J. Andruszkw et al., First measurement of HERA luminosity by ZEUS lumi monitor, preprint DESY-92-066 (1992) [http://inspirehep.net/search?p=find+IRN+2544008
Web End =INSPIRE ].
[33] ZEUS collaboration, M. Derrick et al., Measurement of total and partial photon proton cross-sections at 180-GeV center-of-mass energy, http://dx.doi.org/10.1007/BF01580320
Web End =Z. Phys. C 63 (1994) 391 [http://inspirehep.net/search?p=find+J+Z.Physik,C63,391
Web End =INSPIRE ].
[34] J. Andruszkow et al., Luminosity measurement in the ZEUS experiment, Acta Phys. Polon. B 32 (2001) 2025 [http://inspirehep.net/search?p=find+J+ActaPhys.Pol.,B32,2025
Web End =INSPIRE ].
[35] M. Helbich et al., The Spectrometer system for measuring ZEUS luminosity at HERA, http://dx.doi.org/10.1016/j.nima.2006.06.049
Web End =Nucl. Instrum. Meth. A 565 (2006) 572 [http://arxiv.org/abs/physics/0512153
Web End =physics/0512153 ] [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A565,572
Web End =INSPIRE ].
[36] J. Smith and W. van Neerven, QCD corrections to heavy avor photoproduction and electroproduction, http://dx.doi.org/10.1016/0550-3213(92)90476-R
Web End =Nucl. Phys. B 374 (1992) 36 [http://inspirehep.net/search?p=find+J+Nucl.Phys.,B374,36
Web End =INSPIRE ].
[37] B. Harris and J. Smith, Heavy quark correlations in deep inelastic electroproduction, http://dx.doi.org/10.1016/0550-3213(95)00256-R
Web End =Nucl. Phys. B 452 (1995) 109 [http://arxiv.org/abs/hep-ph/9503484
Web End =hep-ph/9503484 ] [http://inspirehep.net/search?p=find+J+Nucl.Phys.,B452,109
Web End =INSPIRE ].
[38] B. Harris and J. Smith, Invariant mass distributions for heavy quarkantiquark pairs in deep inelastic electroproduction, http://dx.doi.org/10.1016/0370-2693(95)00571-2
Web End =Phys. Lett. B 353 (1995) 535 [Erratum ibid. B 359 (1995) 423] [http://arxiv.org/abs/hep-ph/9502312
Web End =hep-ph/9502312 ] [http://inspirehep.net/search?p=find+J+Phys.Lett.,B353,535
Web End =INSPIRE ].
[39] H1 and ZEUS collaborations, F.D. Aaron et al., Combined Measurement and QCD Analysis of the Inclusive ep Scattering Cross Sections at HERA, http://dx.doi.org/10.1007/JHEP01(2010)109
Web End =JHEP 01 (2010) 109 [arXiv:0911.0884] [http://inspirehep.net/search?p=find+J+JHEP,1001,109
Web End =INSPIRE ].
[40] V. Kartvelishvili, A. Likhoded and V. Petrov, On the Fragmentation Functions of Heavy Quarks Into Hadrons, http://dx.doi.org/10.1016/0370-2693(78)90653-6
Web End =Phys. Lett. B 78 (1978) 615 [http://inspirehep.net/search?p=find+J+Phys.Lett.,B78,615
Web End =INSPIRE ].
[41] E. Lohrmann, A Summary of Charm Hadron Production Fractions, arXiv:1112.3757 [http://inspirehep.net/search?p=find+EPRINT+arXiv:1112.3757
Web End =INSPIRE ].
13
JHEP05(2013)097
[42] M. Aivazis, J.C. Collins, F.I. Olness and W.-K. Tung, Leptoproduction of heavy quarks. 2. A Unied QCD formulation of charged and neutral current processes from xed target to collider energies, http://dx.doi.org/10.1103/PhysRevD.50.3102
Web End =Phys. Rev. D 50 (1994) 3102 [http://arxiv.org/abs/hep-ph/9312319
Web End =hep-ph/9312319 ] [http://inspirehep.net/search?p=find+J+Phys.Rev.,D50,3102
Web End =INSPIRE ].
[43] M. Buza, Y. Matiounine, J. Smith, R. Migneron and W. van Neerven, Heavy quark coe cient functions at asymptotic values Q2 m2, http://dx.doi.org/10.1016/0550-3213(96)00228-3
Web End =Nucl. Phys. B 472 (1996) 611
[http://arxiv.org/abs/hep-ph/9601302
Web End =hep-ph/9601302 ] [http://inspirehep.net/search?p=find+J+Nucl.Phys.,B472,611
Web End =INSPIRE ].
[44] J.C. Collins, Hard scattering factorization with heavy quarks: a General treatment, http://dx.doi.org/10.1103/PhysRevD.58.094002
Web End =Phys. Rev. D 58 (1998) 094002 [http://arxiv.org/abs/hep-ph/9806259
Web End =hep-ph/9806259 ] [http://inspirehep.net/search?p=find+J+Phys.Rev.,D58,094002
Web End =INSPIRE ].
[45] R. Thorne and R. Roberts, A Practical procedure for evolving heavy avor structure functions, http://dx.doi.org/10.1016/S0370-2693(97)01580-3
Web End =Phys. Lett. B 421 (1998) 303 [http://arxiv.org/abs/hep-ph/9711223
Web End =hep-ph/9711223 ] [http://inspirehep.net/search?p=find+J+Phys.Lett.,B421,303
Web End =INSPIRE ].
[46] R. Thorne and R. Roberts, An Ordered analysis of heavy avor production in deep inelastic scattering, http://dx.doi.org/10.1103/PhysRevD.57.6871
Web End =Phys. Rev. D 57 (1998) 6871 [http://arxiv.org/abs/hep-ph/9709442
Web End =hep-ph/9709442 ] [http://inspirehep.net/search?p=find+J+Phys.Rev.,D57,6871
Web End =INSPIRE ].
[47] H1 and ZEUS collaborations, HERAPDF1.5 LHPDF grid, available on https://www.desy.de/h1zeus/combined_results/index.php?do=proton_structure
Web End =https://www.desy.de/h1zeus/combined results/index.php?do=proton structure .
[48] V. Radescu, Combination and QCD Analysis of the HERA Inclusive Cross sections, in proceedings of 35th International Conference of High Energy Physics, http://pos.sissa.it/cgi-bin/reader/contribution.cgi?id=PoS(ICHEP 2010)168
Web End =PoS(ICHEP 2010)168 .
[49] H. Jung, Hard di ractive scattering in high-energy e p collisions and the Monte Carlo generator RAPGAP, http://dx.doi.org/10.1016/0010-4655(94)00150-Z
Web End =Comput. Phys. Commun. 86 (1995) 147 [http://inspirehep.net/search?p=find+J+Comp.Phys.Comm.,86,147
Web End =INSPIRE ].
[50] A. Kwiatkowski, H. Spiesberger and H. Mhring, HERACLES: an event generator for e p interactions at HERA energies including radiative processes: version 1.0,http://dx.doi.org/10.1016/0010-4655(92)90136-M
Web End =Comput. Phys. Commun. 69 (1992) 155 [W. Buchmller and G.Ingelman eds., Proceedings of Workshop Physics at HERA, DESY, Hamburg (1991)] [http://inspirehep.net/search?p=find+J+Comp.Phys.Comm.,69,155
Web End =INSPIRE ].
[51] T. Sjstrand, L. Lnnblad and S. Mrenna, PYTHIA 6.2: physics and manual, http://arxiv.org/abs/hep-ph/0108264
Web End =hep-ph/0108264 [http://inspirehep.net/search?p=find+EPRINT+hep-ph/0108264
Web End =INSPIRE ].
[52] CTEQ collaboration, H. Lai et al., Global QCD analysis of parton structure of the nucleon: CTEQ5 parton distributions, http://dx.doi.org/10.1007/s100529900196
Web End =Eur. Phys. J. C 12 (2000) 375 [http://arxiv.org/abs/hep-ph/9903282
Web End =hep-ph/9903282 ] [http://inspirehep.net/search?p=find+J+Eur.Phys.J.,C12,375
Web End =INSPIRE ].
[53] M. Glck, E. Reya and A. Vogt, Parton structure of the photon beyond the leading order, http://dx.doi.org/10.1103/PhysRevD.45.3986
Web End =Phys. Rev. D 45 (1992) 3986 [http://inspirehep.net/search?p=find+J+Phys.Rev.,D45,3986
Web End =INSPIRE ].
[54] H1 collaboration, C. Adlo et al., D meson production in deep inelastic di ractive interactions at HERA, http://dx.doi.org/10.1016/S0370-2693(01)01155-8
Web End =Phys. Lett. B 520 (2001) 191 [http://arxiv.org/abs/hep-ex/0108047
Web End =hep-ex/0108047 ] [http://inspirehep.net/search?p=find+J+Phys.Lett.,B520,191
Web End =INSPIRE ].
[55] Particle Data Group collaboration, K. Nakamura et al., Review of particle physics,http://dx.doi.org/10.1088/0954-3899/37/7A/075021
Web End =J. Phys. G 37 (2010) 075021 [http://inspirehep.net/search?p=find+J+J.Phys.,G37,075021
Web End =INSPIRE ].
[56] R. Brun et al., Geant3, Technical Report CERN-DD-EE-84-1, CERN (1987) [http://inspirehep.net/search?p=find+IRN+1776738
Web End =INSPIRE ].
[57] W.H. Smith, K. Tokushuku and L.W. Wiggers, The ZEUS trigger system, in proceedings of Computing in High-Energy Physics (CHEP), Annecy, France, September 1992, [C. Verkerk and W. Wojcik eds., CERN, Geneva, Switzerland (1992), pg. 222, DESY 92-150B] [http://inspirehep.net/search?p=find+IRN+2657406
Web End =INSPIRE ].
[58] P.D. Allfrey et al., The design and performance of the ZEUS global tracking trigger, http://dx.doi.org/10.1016/j.nima.2007.06.106
Web End =Nucl. Instrum. Meth. A 580 (2007) 1257 [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A580,1257
Web End =INSPIRE ].
[59] G.M. Briskin, Di ractive dissociation in ep deep inelastic scattering, Ph.D. thesis, Tel Aviv University, Israel, DESY-THESIS 1998-036 (1998) [http://inspirehep.net/search?p=find+IRN+3938123
Web End =INSPIRE ].
[60] H. Abramowicz, A. Caldwell and R. Sinkus, Neural network based electron identication in the ZEUS calorimeter, http://dx.doi.org/10.1016/0168-9002(95)00612-5
Web End =Nucl. Instrum. Meth. A 365 (1995) 508 [http://arxiv.org/abs/hep-ex/9505004
Web End =hep-ex/9505004 ] [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A365,508
Web End =INSPIRE ].
14
JHEP05(2013)097
[61] U. Bassler and G. Bernardi, On the kinematic reconstruction of deep inelastic scattering at HERA: the Sigma method, http://dx.doi.org/10.1016/0168-9002(95)00173-5
Web End =Nucl. Instrum. Meth. A 361 (1995) 197 [http://arxiv.org/abs/hep-ex/9412004
Web End =hep-ex/9412004 ] [http://inspirehep.net/search?p=find+J+Nucl.Inst.Meth.,A361,197
Web End =INSPIRE ].[62] F. Jacquet and A. Blondel, Detection of the charge current events - Method II, in proceedings of Study for an ep Facility for Europe, [U. Amaldi ed., Hamburg, Germany (1979), pg. 391, preprint DESY-79-48].
[63] O. Bachynska, Measurement of D meson production in deep-inelastic scattering at HERA, Ph.D. thesis, Hamburg University, Germany, http://www-library.desy.de/preparch/desy/thesis/desy-thesis-12-045.pdf
Web End =DESY-THESIS 2012-045 (2012).
[64] French-Soviet, CERN-Soviet collaborations, P. Granet et al., Inclusive Production Cross-Sections of Resonances in 32-GeV/c K+ p Interactions,http://dx.doi.org/10.1016/0550-3213(78)90002-0
Web End =Nucl. Phys. B 140 (1978) 389 [http://inspirehep.net/search?p=find+J+Nucl.Phys.,B140,389
Web End =INSPIRE ].
[65] Particle Data Group collaboration, J. Beringer et al., Review of Particle Physics, http://dx.doi.org/10.1103/PhysRevD.86.010001
Web End =Phys. Rev. D 86 (2012) 010001 [http://inspirehep.net/search?p=find+J+Phys.Rev.,D86,010001
Web End =INSPIRE ].
[66] ZEUS collaboration, J. Breitweg et al., Di erential cross-sections of D photoproduction in ep collisions at HERA, http://dx.doi.org/10.1016/S0370-2693(97)00422-X
Web End =Phys. Lett. B 401 (1997) 192 [http://arxiv.org/abs/hep-ex/9704011
Web End =hep-ex/9704011 ] [http://inspirehep.net/search?p=find+J+Phys.Lett.,B401,192
Web End =INSPIRE ].
[67] ZEUS collaboration, J. Breitweg et al., Measurement of inclusive D and associated dijet cross-sections in photoproduction at HERA, http://dx.doi.org/10.1007/s100529801017
Web End =Eur. Phys. J. C 6 (1999) 67 [http://arxiv.org/abs/hep-ex/9807008
Web End =hep-ex/9807008 ] [http://inspirehep.net/search?p=find+J+Eur.Phys.J.,C6,67
Web End =INSPIRE ].[68] ZEUS collaboration, S. Chekanov et al., Measurement of beauty production in deep inelastic scattering at HERA, http://dx.doi.org/10.1016/j.physletb.2004.08.048
Web End =Phys. Lett. B 599 (2004) 173 [http://arxiv.org/abs/hep-ex/0405069
Web End =hep-ex/0405069 ] [http://inspirehep.net/search?p=find+J+Phys.Lett.,B599,173
Web End =INSPIRE ].
[69] ZEUS collaboration, H. Abramowicz et al., Measurement of beauty production in DIS and F bb2 extraction at ZEUS, http://dx.doi.org/10.1140/epjc/s10052-010-1423-2
Web End =Eur. Phys. J. C 69 (2010) 347 [arXiv:1005.3396] [http://inspirehep.net/search?p=find+J+Eur.Phys.J.,C69,347
Web End =INSPIRE ].
[70] ZEUS collaboration, H. Abramowicz et al., Measurement of beauty production in deep inelastic scattering at HERA using decays into electrons, http://dx.doi.org/10.1140/epjc/s10052-011-1573-x
Web End =Eur. Phys. J. C 71 (2011) 1573 [arXiv:1101.3692] [http://inspirehep.net/search?p=find+J+Eur.Phys.J.,C71,1573
Web End =INSPIRE ].
[71] V. Libov, Measurement of charm and beauty production in deep inelastic scattering at HERA, Ph.D. thesis, Hamburg University, Germany (2013).
[72] S. Shimizu, Measurement of the Proton Longitudinal Structure Function FL at HERA, Ph.D. thesis, KEK, Tokyo University, Japan, http://www-zeus.desy.de/physics/sfe/theses/shimaFL.pdf
Web End =KEK-2009-1 .
[73] ZEUS collaboration, S. Chekanov et al., Measurement of the open charm contribution to the di ractive proton structure function, http://dx.doi.org/10.1016/j.nuclphysb.2003.09.001
Web End =Nucl. Phys. B 672 (2003) 3 [http://arxiv.org/abs/hep-ex/0307068
Web End =hep-ex/0307068 ] [http://inspirehep.net/search?p=find+J+Nucl.Phys.,B672,3
Web End =INSPIRE ].
15
JHEP05(2013)097
pDT
ddpDT stat syst Cr
( GeV) (nb/ GeV) (%) (%)1.50 : 1.88 2.16 9.9 +7.0
5.5 1.031.88 : 2.28 2.30 5.8 +5.4
5.8 1.042.28 : 2.68 1.95 4.4 +5.0
4.4 1.032.68 : 3.08 1.63 4.0 +4.7
4.0 1.033.08 : 3.50 1.22 3.8 +4.9
4.2 1.043.50 : 4.00 9.71101 3.4
+4.4
3.7 1.03
JHEP05(2013)097
4.00 : 4.75 6.26101 3.2
+4.2
3.5 1.05
4.75 : 6.00 3.32101 3.0
+4.3
3.7 1.01
6.00 : 8.00 1.21101 4.1
+4.1
3.8 1.06
8.00 : 11.00 3.31102 6.0
+4.4
3.7 1.11
6.1 1.11
Table 1. Dierential cross section for D production in pD T, in the kinematic range 5 < Q2 < 1000 GeV2, 0.02 < y < 0.7, 1.5 < pD T < 20 GeV, | D | < 1.5. The columns list the bin range,
the bin-averaged dierential cross section, the statistical, stat, and systematic, syst, uncertainties, and the QED correction factors, Cr. The overall normalization uncertainties from the luminosity (1.9%) and branching ratio of the D decay channel (1.5%) are not included.
D d
d D stat syst Cr
(nb) (%) (%)
1.50 : 1.25 1.48 7.5
+6.8
6.7 1.06
11.00 : 20.00 3.60103 12
+5.3
1.25 : 1.00 1.66 5.4
+5.6
5.3 1.05
1.00 : 0.75 1.61 4.9
+6.1
4.4 1.05
0.75 : 0.50 1.85 4.2
+4.6
3.8 1.03
3.5 1.03
0.25 : 0.00 2.02 4.0 +4.33.7 1.04
0.00 : 0.25 1.90 4.4 +4.2
3.4 1.04 0.25 : 0.50 1.97 4.4 +4.3
3.3 1.05 0.50 : 0.75 1.96 4.7 +4.5
3.6 1.03 0.75 : 1.00 2.02 4.9 +4.8
4.2 1.02 1.00 : 1.25 2.00 5.8 +5.3
5.1 1.01 1.25 : 1.50 1.84 7.7 +7.4
5.6 1.01
Table 2. Dierential cross section of D production in D . See table 1 for other details.
16
0.50 : 0.25 1.94 4.2
+4.3
zD d
dzD stat syst Cr
(nb) (%) (%)0.000 : 0.100 3.02 12 +8.6
7.1 1.000.100 : 0.200 6.83 6.1 +6.1
5.0 1.010.200 : 0.325 8.18 3.5 +5.5
4.9 1.020.325 : 0.450 9.20 2.5 +4.6
3.8 1.030.450 : 0.575 9.14 2.3 +4.6
4.0 1.050.575 : 0.800 5.12 2.4 +6.5
5.1 1.070.800 : 1.000 0.063 9.1 +9.9
8.5 1.07
Table 3. Dierential cross section of D production in zD . See table 1 for other details.
JHEP05(2013)097
dQ2 stat syst Cr
( GeV2) (nb/ GeV2) (%) (%)5.0 : 8.0 0.499 3.9 +6.7
6.1 1.038.0 : 10.0 0.307 4.3 +6.0
5.2 1.0310.0 : 13.0 0.222 4.0 +4.9
4.1 1.0213.0 : 19.0 0.125 3.5 +5.6
5.0 1.0319.0 : 27.5 0.752101 3.7
Q2 d
+4.9
4.0 1.04
27.5 : 40.0 0.415101 3.9
+4.8
3.8 1.04
40.0 : 60.0 0.169101 4.7
+5.6
5.6 1.05
5.1 1.06 100.0 : 200.0 0.171102 7.8
+6.6
60.0 : 100.0 0.747102 5.0
+7.1
5.2 1.14
Table 4. Dierential cross section of D production in Q2. See table 1 for other details.
17
4.4 1.07 200.0 : 1000.0 0.140103 13
+6.1
y d
dy stat syst Cr
(nb) (%) (%)0.02 : 0.05 1.20 101 7.9
+16
12 1.07
0.05 : 0.09 2.07 101 3.4
+6.7
6.5 1.05
0.09 : 0.13 1.79 101 3.4
+4.5
4.0 1.04
JHEP05(2013)097
0.13 : 0.18 1.37 101 3.6
+4.6
4.8 1.04
3.7 1.040.26 : 0.36 8.03 3.7 +4.8
4.0 1.030.36 : 0.50 5.09 4.2 +5.2
4.5 1.020.50 : 0.70 2.90 6.0 +9.3
7.1 1.01
Table 5. Dierential cross section of D production in y. See table 1 for other details.
0.18 : 0.26 1.13 101 3.3
+4.8
dx stat syst Cr
(nb) (%) (%)(0.8 : 4.0) 104 0.475 104 3.5
x d
+6.0
5.3 1.06
(0.4 : 1.6) 103 0.198 104 2.1
+4.8
3.9 1.03
(1.6 : 5.0) 103 0.357 103 2.6
+4.9
3.9 1.02
(0.5 : 1.0) 102 0.553 102 5.7
+6.3
5.1 0.99
8.4 1.08
Table 6. Dierential cross section of D production in x. See table 1 for other details.
18
(0.1 : 1.0) 101 0.159 101 10.7
+9.2
Q2 y vis stat syst beautyvis Cr ( GeV2) (pb) (%) (%) (pb)
0.020 : 0.050 120 23 +19
20 0.0 1.040.050 : 0.090 279 10 +11
11 1.5 1.040.090 : 0.160 421 6.0 +6.8
7.0 5.2 1.040.160 : 0.320 550 5.3 +6.5
5.8 11.0 1.030.320 : 0.700 456 6.8 +6.3
5.5 18.2 1.02
0.020 : 0.050 108 14 +17
12 0.1 1.050.050 : 0.090 178 6.5 +7.0
6.0 1.2 1.040.090 : 0.160 220 5.8 +4.7
4.6 2.9 1.030.160 : 0.320 352 5.1 +4.5
3.7 8.1 1.020.320 : 0.700 307 7.2 +6.6
5.0 12.5 1.00
0.020 : 0.050 65.1 15 +16
12 0.2 1.070.050 : 0.090 160 6.4 +6.2
7.2 1.2 1.040.090 : 0.160 205 5.6 +4.7
4.7 3.1 1.030.160 : 0.320 267 5.9 +4.9
4.4 9.0 1.030.320 : 0.700 250 7.4 +5.7
6.7 13.5 1.01
0.020 : 0.050 37.1 29 +18
18 0.1 1.080.050 : 0.090 134 7.0 +7.5
7.8 0.9 1.060.090 : 0.160 196 5.3 +4.4
4.3 3.6 1.050.160 : 0.320 275 5.1 +4.1
3.4 10.2 1.030.320 : 0.700 284 6.1 +6.4
4.5 14.7 1.02
0.020 : 0.050 14.2 38 +35
18 0.0 1.250.050 : 0.090 72.1 9.6 +8.0
7.2 1.2 1.070.090 : 0.160 87.0 8.4 +4.9
4.6 3.9 1.040.160 : 0.320 182 5.7 +5.3
3.9 9.4 1.040.320 : 0.700 175 7.6 +6.6
5.6 14.0 1.02
0.020 : 0.350 80.2 11 +7.6
4.2 5.8 1.10.350 : 0.700 45.1 16 +7.6
7.8 5.0 0.99
0.020 : 0.300 59.8 14 +4.8
0.300 : 0.700 37.3 17 +6.6
0.020 : 0.275 28.4 24 +8.2
10 2.4 1.260.275 : 0.700 46.7 21 +8.7
5.1 6.9 1.07
Table 7. Visible cross sections, vis, for D production in bins of Q2 and y. The second but last column reports the estimated contribution from beauty decays, based on the Rapgap beauty MC rescaled to ZEUS data. See table 1 for other details.
19
5 : 9
JHEP05(2013)097
9 : 14
14 : 23
23 : 45
45 : 100
100 : 158
6.3 3.5 1.16
158 : 251
4.9 4.3 1.04
251 : 1000
Q2 ( GeV2) y 1 2 3 4 5 6 7 9 11 12 13 14 15 16 17 (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%)
0.020 : 0.050 +11
12
+1.8 +0.6
+7.4 2.7
+9.09.0 -7.0 -3.4
+2.5 2.4
+2.5 2.5
+8.8 8.8
+0.0 0.0
+0.0 +0.0
4.2+4.2 +1.8
+0.10.1 +2.2
0.050 : 0.090 +3.5
4.0
+5.1 4.8
+2.3 3.0
+6.66.6 +0.7 -1.9
+2.4 2.2
+2.1 2.1
+3.4 3.4
0.1 +0.1
+0.0 +0.0
1.9+2.3 +3.0
0.7+0.8 -1.6
5 : 9
0.090 : 0.160 +1.5
3.4
+3.3 4.0
+2.6 1.5
+1.11.1 +1.0 +0.5
+2.3 2.2
+1.8 1.8
+2.3 2.3
+0.1 0.1
+0.0 +0.0
+0.60.8 +1.8
1.4+1.5 -2.0
0.160 : 0.320 +0.9
+0.1
+2.9 2.7
+1.1 0.8
+3.53.5 +0.6 +0.3
+2.2 2.1
+1.8 1.8
+1.6 1.6
0.0 0.0
+0.3 0.5
+0.70.9 -0.5
1.7+1.8 +0.7
JHEP05(2013)097
0.320 : 0.700 1.5
+1.7
+1.9 0.7
+0.5 0.6
+1.91.9 +0.2 -1.5
+2.0 1.9
+1.9 1.9
+1.7 1.7
0.0 0.0
+1.4 2.8
+0.30.4 -0.6
1.4+1.5 +3.1
4.8 +7.3
+1.5 2.5
2.5+2.5 -0.1 -2.1
+2.2 2.1
+2.4 2.4
+6.1 6.1
+0.1 0.1
+0.0 +0.0
4.5+4.7 +3.0
0.7+0.7 +1.4
0.050 : 0.090 +3.1
3.2
+0.2 +1.9
+1.0 1.3
+2.12.1 +0.6 +0.1
+2.2 2.1
+2.0 2.0
+2.4 2.4
+0.0 0.0
+0.0 0.0
1.2+1.5 +2.7
1.2+1.2 -1.6
9 : 14
0.020 : 0.050 +11
6.9
0.090 : 0.160 +0.5
0.6
0.1 +0.3
+1.2 0.6
+1.61.6 +0.5 -0.3
+2.1 2.0
+1.7 1.7
+1.7 1.7
0.2 +0.2
0.0 +0.0
0.1+0.1 +0.8
1.6+1.7 -2.0
0.160 : 0.320 +0.0
+0.5
+0.2 +0.5
+0.3 0.7
0.5+0.5 +0.3 +0.5
+2.1 2.0
+1.8 1.8
+1.5 1.5
0.1 +0.1
+0.1 0.1
+0.60.7 +1.1
1.8+1.9 +0.4
0.320 : 0.700 2.8
+3.8
+1.1 0.7
+0.1 0.1
0.4+0.4 +0.4 -0.2
+1.9 1.9
+1.8 1.8
+1.9 1.9
+0.2 0.3
+0.8 1.6
+0.40.5 +0.2
1.8+2.0 +2.8
3.8 +6.4
+0.4 0.2
0.0+0.0 +0.3 +2.5
+2.1 2.0
+2.4 2.4
+6.0 6.0
+0.2 0.2
+0.0 +0.0
2.7+2.4 +4.1
0.8+0.8 +1.7
0.050 : 0.090 +2.5
3.9
3.8 +1.5
+0.3 0.3
0.9+0.9 +0.2 +1.0
+2.1 2.0
+2.0 2.0
+2.3 2.3
+0.1 0.1
+0.0 +0.0
0.9+1.1 +2.3
1.9+1.8 -1.7
14 : 23
0.020 : 0.050 +12
8.8
0.090 : 0.160 +1.3
+0.4
0.4 +0.8
+0.2 0.3
0.3+0.3 -1.0 -1.6
+2.0 1.9
+1.7 1.7
+1.6 1.6
0.1 +0.1
+0.0 0.0
+0.30.4 +0.7
2.3+2.2 -2.0
0.160 : 0.320 0.9
+0.5
0.6 0.2
+0.0 0.0
+0.60.6 -0.9 +1.7
+1.9 1.9
+1.7 1.7
+1.4 1.4
+0.1 0.2
+0.2 0.3
+1.01.3 +0.4
2.6+2.6 +0.4
0.320 : 0.700 2.9
+1.3
0.3 1.7
+0.0 0.0
+0.10.1 -0.3 -3.1
+1.9 1.8
+1.8 1.8
+1.8 1.8
+0.2 0.3
+1.0 1.9
+0.30.4 -1.5
2.7+2.7 +2.9
6.7 +12
+0.0 0.0
0.0+0.0 +1.3 -13
+1.9 1.8
+2.2 2.2
+7.0 7.0
0.3 +0.3
+0.0 +0.0
2.3+2.4 +3.7
0.6+0.6 +1.7
0.050 : 0.090 +4.3
4.6
4.8 +4.3
+0.0 0.0
0.0+0.0 -0.3 -0.2
+1.8 1.7
+1.9 1.9
+2.3 2.3
+0.0 0.0
+0.0 +0.0
0.4+0.5 +0.1
1.5+1.6 -1.4
23 : 45
0.020 : 0.050 +9.5
8.4
0.090 : 0.160 +0.9
1.1
1.4 +1.8
+0.0 0.0
0.0+0.0 +0.3 -0.1
+1.8 1.7
+1.6 1.6
+1.5 1.5
+0.2 0.3
0.0 +0.0
0.3+0.3 +0.0
1.7+1.7 -2.1
0.160 : 0.320 1.0
+1.2
0.3 0.4
+0.0 0.0
0.0+0.0 +0.2 +0.1
+1.8 1.7
+1.6 1.6
+1.3 1.3
+0.1 0.2
+0.1 0.2
+0.00.1 +0.7
1.8+1.8 +0.4
0.320 : 0.700 2.6
+3.5
+0.0 +1.1
+0.0 0.0
0.0+0.0 +1.0 +0.0
+1.8 1.7
+1.8 1.8
+1.5 1.5
0.2 +0.1
+0.6 1.3
+0.20.2 +2.1
1.7+1.7 +2.4
9.7 +18
+0.0 0.0
0.0+0.0 -0.1 +2.3
+1.5 1.4
+2.0 2.0
+13 13
+0.0 +0.0
+0.0 +0.0
2.6+3.4 +5.0
2.2+2.0 +3.5
0.050 : 0.090 +4.2
3.5
4.0 +3.7
+0.0 0.0
0.0+0.0 -2.0 -0.1
+1.5 1.5
+1.8 1.8
+3.1 3.1
+0.1 0.1
+0.0 +0.0
0.2+0.0 +3.3
1.4+1.3 -1.6
45 : 100
0.020 : 0.050 +26
6.4
0.090 : 0.160 +1.1
0.7
2.0 +2.4
+0.0 0.0
0.0+0.0 -0.8 -0.3
+1.5 1.4
+1.5 1.5
+1.7 1.7
+0.3 0.4
+0.0 0.0
0.0+0.0 +1.5
1.9+1.7 -2.1
0.160 : 0.320 0.7
0.1
1.5 +1.9
+0.0 0.0
0.0+0.0 +0.3 +0.5
+1.6 1.5
+1.5 1.5
+1.4 1.4
+0.6 0.7
+0.0 0.0
0.0+0.0 +3.0
2.3+2.1 +0.2
0.320 : 0.700 2.8
+3.2
0.8 0.3
+0.0 0.0
0.0+0.0 -0.6 -2.4
+1.7 1.6
+1.6 1.6
+1.6 1.6
+0.5 0.7
+0.4 0.9
0.6+0.7 +2.4
2.7+2.5 +2.9
1.3 +4.4
+0.0 0.0
0.0+0.0 -2.2 +4.4
+1.3 1.3
+1.4 1.4
+1.8 1.8
+0.9 1.1
+0.0 0.0
0.2+0.2 +1.3
1.3+1.2 -0.2
100 : 158
0.020 : 0.350 +1.7
0.6
0.350 : 0.700 5.3
+0.8
2.5 0.9
+0.0 0.0
0.0+0.0 +1.8 +4.4
+1.4 1.4
+1.5 1.5
+2.9 2.9
+2.6 3.2
+0.5 1.1
+0.10.4 -0.2
1.3+1.1 +2.9
4.3 +2.0
+0.0 0.0
0.0+0.0 -1.9 -0.3
+1.2 1.2
+1.3 1.3
+3.0 3.0
+0.8 1.0
+0.1 0.1
+0.40.6 -1.3
0.9+0.8 +0.1
158 : 251
0.020 : 0.300 +0.3
0.8
0.300 : 0.700 2.6
+2.6
0.2 +0.6
+0.0 0.0
0.0+0.0 +1.8 +1.7
+1.4 1.3
+1.4 1.4
+3.0 3.0
+0.1 0.7
+0.5 1.0
+0.30.5 +1.1
1.0+0.9 +3.0
5.8 +5.9
+0.0 0.0
0.0+0.0 -4.6 -0.0
+1.2 1.2
+1.3 1.3
+4.6 4.6
+0.8 1.3
+0.0 +0.0
1.0+0.9 -3.3
+0.10.1 -0.3
251 : 1000
0.020 : 0.275 0.6
2.2
0.275 : 0.700 0.8
+4.3
1.7 +3.8
+0.0 0.0
0.0+0.0 +2.5 +3.5
+1.4 1.3
+1.4 1.4
+3.6 3.6
0.1 0.1
+0.7 1.4
0.5+0.4 -1.4
1.0+0.9 +0.9
Table 8. Individual systematical uncertainties as dened in section 7 for the double-dierential cross sections in bins of Q2 and y. The uncertainty 8 and 10 are not reported as 8 is constant (+2 %) and 10 was found to be negligible. The overall normalisation uncertanties 18 = 1.9%
and 19 = 1.5% are also not listed.
20
Q2 x mc s K kT b ( GeV2) (%) (%) (%) (%) (%) (%)
0.00160 +8.3
5.6
6.5 +14
+0.6 +0.2
4.5 +7.5
0.2 +0.6
0.0
0.00080 +0.3
+1.0
3.9 +7.8
0.3 +0.6
3.5 +6.1
1.3 +1.3
0.3
7 0.00050
1.3 +2.0
3.2 +5.0
+0.1 +0.8
2.9 +6.5
1.3 +1.8
0.6
0.00030
3.2 +3.3
1.4 +0.2
0.9 +1.2
2.6 +5.9
2.5 +2.2
1.0
0.00013
3.7 +5.7
+4.7
6.3
1.6 +2.5
2.4 +5.9
4.0 +4.2
2.2
JHEP05(2013)097
0.00300 +9.5
6.2
6.5 +15
+1.4 +0.0
3.6 +8.0
+1.6 +0.1
0.0
0.00150 +0.1
1.1
5.4 +7.8
0.1
0.6
3.3 +5.3
0.7
0.1
0.3
12 0.00080
0.6 +0.8
3.8 +5.7
0.1 +0.1
2.5 +5.5
0.9 +1.0
0.7
0.00050
2.5 +2.2
2.5 +2.0
0.5 +0.0
2.4 +5.0
1.9 +1.2
1.2
0.00022
3.2 +3.9
+3.1
4.4
1.6 +1.7
2.2 +5.4
3.1 +1.8
2.2
0.00450 +8.8
6.1
6.5 +13
+0.9 +0.7
3.2 +6.2
+1.1
1.0
0.1
0.00250 +0.3
0.9
5.7 +7.0
+0.4
0.6
3.2 +3.7
0.3
0.6
0.4
18 0.00135
0.4 +0.8
4.4 +6.1
+0.6 +0.1
2.4 +4.8
0.5 +0.6
0.8
0.00080
1.5 +1.0
4.0 +3.2
+0.3 +0.3
1.9 +4.4
0.9 +0.7
1.8
0.00035
3.0 +2.7
+1.8
3.7
1.0 +1.0
2.5 +4.5
2.9 +1.4
3.0
0.00800 +8.4
7.3
7.0 +11
+0.6
0.5
3.5 +5.1
+0.3
1.7
0.1
0.00550 +1.3
0.0
5.8 +8.4
+0.5
0.3
1.9 +3.2
+0.3
0.3
0.3
32 0.00240 +0.5
+0.5
3.6 +6.4
0.1 +0.3
1.7 +3.9
0.2 +0.0
0.9
0.00140
0.5 +1.3
3.5 +4.6
+0.2 +0.1
1.6 +3.9
0.4 +0.6
2.0
0.00080
2.9 +3.0
0.4
1.6
0.8 +0.5
2.2 +3.6
2.2 +1.1
2.9
0.01500 +9.3
6.5
5.2 +10
+0.6 +0.4
1.8 +6.2
+1.6 +0.4
0.0
0.00800 +0.6
1.7
4.8 +6.0
0.3
0.7
1.9 +2.3
0.1
0.6
0.9
60 0.00500
0.2 +0.8
3.9 +5.2
+0.1
0.0
1.4 +2.7
0.3 +0.3
2.4
0.00320
0.9 +1.4
3.7 +5.0
0.1
0.2
1.6 +2.8
0.4 +0.0
2.9
0.00140
2.4 +1.8
1.5 +1.3
0.1
0.0
1.8 +2.8
1.3 +0.6
4.8
0.01000 +0.2
+0.8
4.6 +5.3
+0.4 +0.1
1.5 +2.3
+0.0 +0.3
4.2
120 0.00200
0.8 +1.3
2.0 +2.3
+0.4
0.5
1.3 +1.9
1.0 +0.8
7.2
0.01300
0.1
0.1
3.7 +3.8
+0.4
0.1
0.9 +1.4
+0.1 +0.0
4.1
200 0.00500
1.9 +1.3
3.8 +3.8
0.3
0.6
1.5 +1.2
0.1 +0.1
7.5
0.02500
0.5 +0.4
3.8 +3.4
0.4
0.0
0.7 +1.2
+0.4
0.4
5.1
350 0.01000
0.2 +1.3
2.8 +3.7
+0.0 +0.3
0.6 +0.9
+0.0 +0.1
10.6
Table 9. Breakdown of the theoretical uncertainty on ccred(x, Q2), showing the uncertainty from the variation of charm mass ( mc), of the renormalisation and factorisation scales ( ), of S ( s), of the fragmentation function ( K ), of the transverse fragmentation ( kT ), and of the expected beauty component ( b). The upper (lower) value gives the eect of a positive (negative) variation of the parameter.
21
Q2 x ccred stat. syst. theo. Aps ( GeV2) (%) (%) (%) (%)
0.00160 0.057 23 +19
20
+18
9.7 0.227
5.4 0.377 7 0.00050 0.164 6.2 +6.8
7.1
+8.7
4.7 0.440
0.00080 0.124 10 +11
11
+10
0.00030 0.187 5.5 +6.7
6.0
+7.3
5.2 0.440
0.00013 0.248 7.4 +6.6
5.7
+11
9.0 0.299
JHEP05(2013)097
0.00300 0.098 14 +17
12
+19
9.7 0.256
6.5 0.423 12 0.00080 0.175 6.0 +4.7
4.6
+8.1
4.7 0.490
0.00150 0.152 6.6 +7.1
6.0
+9.4
0.00050 0.239 5.4 +4.6
3.8
+6.0
4.9 0.492
0.00022 0.335 7.8 +6.9
5.3
+8.1
7.2 0.332
0.00450 0.081 15 +16
12
+17
9.5 0.262
6.7 0.456 18 0.00135 0.199 5.8 +4.7
4.8
+7.9
5.1 0.529
0.00250 0.168 6.5 +6.2
7.2
+8.0
0.00080 0.216 6.3 +5.1
4.6
+5.9
5.0 0.544
0.00035 0.324 8.3 +6.1
7.1
+6.5
6.8 0.370
0.00800 0.068 29 +18
19
+15
11 0.236
6.2 0.478 32 0.00240 0.234 5.5 +4.5
4.4
+7.6
4.1 0.560
0.00550 0.159 7.1 +7.5
7.9
+9.1
0.00140 0.266 5.5 +4.3
3.6
+6.5
4.4 0.594
0.00080 0.390 6.8 +6.8
4.7
+5.7
5.5 0.430
0.01500 0.068 38 +35
18
+15
8.6 0.166
5.6 0.465 60 0.00500 0.161 9.2 +5.2
4.9
+6.4
4.8 0.570
0.00800 0.173 9.9 +8.1
7.3
+6.6
0.00320 0.258 6.4 +5.6
4.1
+6.6
5.1 0.624
0.00140 0.327 9.0 +7.2
6.2
+6.0
6.0 0.516
6.4 0.491 120 0.00200 0.287 21 +8.7
8.9
+7.9
7.7 0.583
0.01000 0.130 12 +8.2
4.6
+7.2
5.6 0.465 200 0.00500 0.239 22 +7.6
5.6
+8.6
8.8 0.624
0.01300 0.176 17 +5.2
6.8
+5.8
6.4 0.433 350 0.01000 0.193 29 +11
6.2
+11
0.02500 0.103 29 +9.0
11
+6.2
11 0.636
Table 10. The reduced cross-section ccred(x, Q2) with statistical, systematic and theoretical uncertainties. The last column shows the kinematical acceptance.
22
JHEP05(2013)097
ZEUS
2000
Combinations per 4 MeV
D
p
0
K
ZEUS D* 363 pb
Wrong-sign combinations
Signal region
-1
1800
1600
1400
1200
1000
800
600
400
200
0 1400 1500 1600 1700 1800 1900 2000 2100 2200
M(K
p
) (MeV)
Figure 1. Distribution of M(K) for D candidates with 143.2<M <147.7 MeV (lled circles) and for wrong-sign combinations (empty circles). The D0 signal region is marked as a shaded area.
23
ZEUS
JHEP05(2013)097
6000
Combinations per 0.45 MeV
D*
K
p
p
s
ZEUS D* 363 pb Wrong-sign combinations
Signal regionBackground fit (correct-sign) Background fit (wrong-sign)
-1
) = 12893
N(D*
185
5000
4000
3000
2000
1000
0 140 145 150 155 160 165 170
M(K
p
p
)-M(K
) (MeV)
s
p
Figure 2. Distribution of the mass dierence, M = M(Ks)M(K), for the D candidates
with 1.80 < M(K) < 1.92 GeV (lled circles) and for wrong-sign combinations (empty circles). The background t described in the text is shown as a dashed (continuous) line for correct-sign (wrong-sign) combinations. The D signal region is marked as a shaded area.
24
ZEUS
)
-1
D*
6000
(GeV
3
10
JHEP05(2013)097
h
D
5000
2
10
D*
/ 4000
D*
T
N
10
3000
p
D
2000
/
1
D*
1000
N
-1
10
2 3 4 5 6 7 8 10
0 -1.5 -1 -0.5 0 0.5 1 1.5
p
D* (GeV)
T
h
D*
)
-2
3
10
y
/ 40000
D
(GeV
2
10
D*
N
30000
2
10
Q
20000
D
1
/
10000
D*
N
-1
10
10 2
10 3
10
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
Q
2 (GeV
2
)
y
30000
D*
ZEUS D* 363 pb
charm(non-diff)
charm(diff)
beauty
photoproduction
z
25000
-1
D
D*
/ 20000
N
15000
10000
5000
0 0 0.2 0.4 0.6 0.8 1
z D*
Figure 3. Number of reconstructed D (lled circles), divided by bin size, as a function of pD T, D , Q2, y and zD . Data are compared to a MC mixture containing non-diractive and diractive charm production in DIS, beauty production, and charm photoproduction. The sum of the MC samples is normalised to the number of D in the data.
25
ZEUS
10
4
2500
(pb/GeV)
(a)
(b)
JHEP05(2013)097
(pb)
2000
10
3
D*
1500
10
h/d s d
2
D*
T
1000
/dp s d
10
500
0
1 2 3 4 5 6 7 10 20
-1.5 -1 -0.5 0 0.5 1 1.5
p
D* (GeV)
h D*
T
12000
(pb)
(c)
10000
ep
e D* X
D*
8000
ZEUS D* 363 pb
-1
/dz s d
6000
HVQDIS + RAPGAP b
1.6
4000
1.1 + b
1.6
2000
RAPGAP BGF c
1.6
RAPGAP b
0 0 0.2 0.4 0.6 0.8 1
z
D*
Figure 4. Dierential D cross sections as a function of (a) pD T, (b) D and (c) zD (lled circles). The error bars show the statistical and systematic uncertainties added in quadrature, the inner bars show the statistical uncertainties alone. Also shown are NLO QCD predictions calculated using Hvqdis (dashed line and shaded area for the uncertainties) and Rapgap MC prediction for charm creation via boson-gluon fusion (long-dashed line). The contribution from b-quark decays, calculated with the Rapgap MC (continuous line), is included in the predictions. The MC cross sections for charm (beauty) are scaled by 1.1 (1.6) as described in the text.
26
ZEUS
JHEP05(2013)097
3
/dy (pb) s d
)
10
25000
2
(a)
(b)
(pb/GeV
10
2
20000
15000
10
10000
2
1
/dQ s d
5000
-1
10
10 2
10 3
10
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
Q
2 (GeV
2
)
y
10
7
(c)
/dx (pb) s d
ep
e D* X
10
6
ZEUS D* 363 pb
1.6
-1
10
HVQDIS + RAPGAP b
RAPGAP BGF c
1.6
RAPGAP b
10
5
4
1.1 + b
1.6
10 -3
10 -2
10 -1
10
-4
x
Figure 5. Dierential D cross sections as a function of (a) Q2, (b) y and (c) x. Other details as in gure 4.
27
JHEP05(2013)097
Figure 6. Double-dierential D cross sections as a function of Q2 and y for 5 < Q2 < 100 GeV 2 (lled circles). The measurements from the H1 collaboration (empty squares) are also shown [17]. Other details as in gure 4.
28
JHEP05(2013)097
Figure 7. Double-dierential D cross sections as a function of Q2 and y for 100 < Q2 < 1000 GeV 2 (lled circles). The measurements from the H1 collaboration (empty triangles) are also shown [16]. Other details as in gure 4.
29
ZEUS
JHEP05(2013)097
p
+
e
2
s/d
1.8
ZEUS D* 363 pb
-1
p
e
- 1.6
s
d
1.4
1.2
1
0.8
0.6
0.4
0.2
0
10 2
10 3
10
2 (GeV
Q
2
)
Figure 8. Ratio of ep to e+p visible D cross sections as a function of Q2. Only statistical uncertainties are shown. Bin boundaries are as in table 4.
30
ZEUS
_ cc
red
Q2= 7 GeV2
Q2= 12 GeV2
Q2= 18 GeV2
s 0.4
0.3
JHEP05(2013)097
0.2
0.1
0
Q2= 32 GeV2
Q2= 60 GeV2
Q2= 120 GeV2
0.4
0.3
0.2
0.1
0
Q2= 200 GeV2
Q2= 350 GeV2
10
-4 10
-3 10
-2
x
0.4
0.3
0.2
ZEUS D* 363 pb-1
ZEUS D+ 354 pb-1
HERA
0.1
0
10
-4 10
-3 10
-2
10
-4 10
-3 10
-2
x
Figure 9. Reduced charm cross sections from D (lled circles) compared to the ZEUS D+ measurement [9] (empty squares) and the combination of previous HERA results [5] (empty circles). The outer error bars include experimental and theoretical uncertainties added in quadrature. The inner error bars in the ZEUS D and D+ measurements show the experimental uncertainties. The inner error bars of the combined HERA data represent the uncorrelated part of the uncertainty.
31
ZEUS
_ cc
red
Q2= 7 GeV2
Q2= 12 GeV2
Q2= 18 GeV2
s 0.4
0.3
JHEP05(2013)097
0.2
0.1
0
Q2= 32 GeV2
Q2= 60 GeV2
Q2= 120 GeV2
0.4
0.3
0.2
0.1
0
Q2= 200 GeV2
Q2= 350 GeV2
10
-4 10
-3 10
-2
x
0.4
ZEUS D* 363 pb-1
0.3
0.2
HERAPDF1.5 NLO mc=1.5 GeV total uncertainty excluding mc
0.1
0
10
-4 10
-3 10
-2
10
-4 10
-3 10
-2
x
Figure 10. Reduced charm cross sections (lled circles) compared to a GM-VFNS calculation based on HERAPDF1.5 parton densities. The inner error bars show the experimental uncertainties and the outer error bars show the experimental and theoretical uncertainties added in quadrature. The outer bands on the HERAPDF1.5 predicition show the total uncertainty while the inner bands correspond to the sum in quadrature of all uncertainties excluding the charm-mass variation.
32
The ZEUS collaboration
H. Abramowicz45,aj, I. Abt35, L. Adamczyk13, M. Adamus54, R. Aggarwal7,c, S. Antonelli4,P. Antonioli3, A. Antonov33, M. Arneodo50, O. Arslan5, V. Aushev26,27,aa, Y. Aushev,27,aa,ab,O. Bachynska15, A. Bamberger19, A.N. Barakbaev25, G. Barbagli17, G. Bari3, F. Barreiro30,N. Bartosik15, D. Bartsch5, M. Basile4, O. Behnke15, J. Behr15, U. Behrens15, L. Bellagamba3,A. Bertolin39, S. Bhadra57, M. Bindi4, C. Blohm15, V. Bokhonov26,aa, T. Bo ld13, E.G. Boos25,K. Borras15, D. Boscherini3, D. Bot15, I. Brock5, E. Brownson56, R. Brugnera40, N. Brmmer37,A. Bruni3, G. Bruni3, B. Brzozowska53, P.J. Bussey20, B. Bylsma37, A. Caldwell35, M. Capua8,R. Carlin40, C.D. Catterall57, S. Chekanov1, J. Chwastowski12,e, J. Ciborowski53,an,R. Ciesielski15,h, L. Cifarelli4, F. Cindolo3, A. Contin4, A.M. Cooper-Sarkar38, N. Coppola15,i,M. Corradi3, F. Corriveau31, M. Costa49, G. DAgostini43, F. Dal Corso39, J. del Peso30, R.K. Dementiev34, S. De Pasquale4,a, M. Derrick1, R.C.E. Devenish38, D. Dobur19,u,B.A. Dolgoshein 33,, G. Dolinska15, A.T. Doyle20, V. Drugakov16, L.S. Durkin37, S. Dusini39,Y. Eisenberg55, P.F. Ermolov 34,, A. Eskreys 12,, S. Fang15,j, S. Fazio8, J. Ferrando20,M.I. Ferrero49, J. Figiel12, B. Foster38,af, G. Gach13, A. Galas12, E. Gallo17, A. Garfagnini40,A. Geiser15, I. Gialas21,x, A. Gizhko15, L.K. Gladilin34, D. Gladkov33, C. Glasman30,O. Gogota27, Yu.A. Golubkov34, P. Gttlicher15,k, I. Grabowska-Bo ld13, J. Grebenyuk15,I. Gregor15, G. Grigorescu36, G. Grzelak53, O. Gueta45, M. Guzik13, C. Gwenlan38,ag, T. Haas15,W. Hain15, R. Hamatsu48, J.C. Hart44, H. Hartmann5, G. Hartner57, E. Hilger5, D. Hochman55,R. Hori47, A. Httmann15, Z.A. Ibrahim10, Y. Iga42, R. Ingbir45, M. Ishitsuka46, A. Iudin27,ac,H.-P. Jakob5, F. Januschek15, T.W. Jones52, M. Jngst5, I. Kadenko27, B. Kahle15, S. Kananov45,T. Kanno46, U. Karshon55, F. Karstens19,v, I.I. Katkov15,l, M. Kaur7, P. Kaur7,c, A. Keramidas36,L.A. Khein34, J.Y. Kim9, D. Kisielewska13, S. Kitamura48,al, R. Klanner22, U. Klein15,m,E. Koeman36, N. Kondrashova27,ad, O. Kononenko27, P. Kooijman36, Ie. Korol15,I.A. Korzhavina34, A. Kotaski14,f, U. Ktz15, N. Kovalchuk27,ae, H. Kowalski15, O. Kuprash15,M. Kuze46, A. Lee37, B.B. Levchenko34, A. Levy45, V. Libov15, S. Limentani40, T.Y. Ling37,M. Lisovyi15, E. Lobodzinska15, W. Lohmann16, B. Lhr15, E. Lohrmann22, K.R. Long23,A. Longhin39,ah, D. Lontkovskyi15, O.Yu. Lukina34, J. Maeda46,ak, S. Magill1, I. Makarenko15,J. Malka15, R. Mankel15, A. Margotti3, G. Marini43, J.F. Martin51, A. Mastroberardino8, M.C.K. Mattingly2, I.-A. Melzer-Pellmann15, S. Mergelmeyer5, S. Miglioranzi15,n, F. Mohamad Idris10, V. Monaco49, A. Montanari15, J.D. Morris6,b, K. Mujkic15,o, B. Musgrave1, K. Nagano24,T. Namsoo15,p, R. Nania3, A. Nigro43, Y. Ning11, T. Nobe46, D. Notz15, R.J. Nowak53, A.E. Nuncio-Quiroz5, B.Y. Oh41, N. Okazaki47, K. Olkiewicz12, Yu. Onishchuk27,K. Papageorgiu21, A. Parenti15, E. Paul5, J.M. Pawlak53, B. Pawlik12, P. G. Pelfer18,A. Pellegrino36, W. Perlaski53,ao, H. Perrey15, K. Piotrzkowski29, P. Pluciski54,ap,N.S. Pokrovskiy25, A. Polini3, A.S. Proskuryakov34, M. Przybycie13, A. Raval15, D.D. Reeder56,B. Reisert35, Z. Ren11, J. Repond1, Y.D. Ri48,am, A. Robertson38, P. Rolo15,n, I. Rubinsky15,M. Ruspa50, R. Sacchi49, U. Samson5, G. Sartorelli4, A.A. Savin56, D.H. Saxon20, M. Schioppa8,S. Schlenstedt16, P. Schleper22, W.B. Schmidke35, U. Schneekloth15, V. Schnberg5,T. Schrner-Sadenius15, J. Schwartz31, F. Sciulli11, L.M. Shcheglova34, R. Shehzadi5,S. Shimizu47,n, I. Singh7,c, I.O. Skillicorn20, W. S lomiski14,g, W.H. Smith56, V. Sola22,A. Solano49, D. Son28, V. Sosnovtsev33, A. Spiridonov15,q, H. Stadie22, L. Stanco39,N. Stefaniuk27, A. Stern45, T.P. Stewart51, A. Stifutkin33, P. Stopa12, S. Suchkov33, G. Susinno8,L. Suszycki13, J. Sztuk-Dambietz22, D. Szuba22, J. Szuba15,r, A.D. Tapper23, E. Tassi8,d,J. Terrn30, T. Theedt15, H. Tiecke36, K. Tokushuku24,y, J. Tomaszewska15,s, A. Trofymov27,ae,V. Trusov27, T. Tsurugai32, M. Turcato22, O. Turkot27,ae,t, T. Tymieniecka54, M. Vzquez36,n,A. Verbytskyi15, O. Viazlo27, N.N. Vlasov19,w, R. Walczak38, W.A.T. Wan Abdullah10,
33
JHEP05(2013)097
J.J. Whitmore41,ai, K. Wichmann15,t, L. Wiggers36, M. Wing52, M. Wlasenko5, G. Wolf15,H. Wolfe56, K. Wrona15, A.G. Yages-Molina15, S. Yamada24, Y. Yamazaki24,z, R. Yoshida1,C. Youngman15, N. Zakharchuk27,ae, A.F. Zarnecki53, L. Zawiejski12, O. Zenaiev15,W. Zeuner15,n, B.O. Zhautykov25, N. Zhmak26,aa, A. Zichichi4, Z. Zolkapli10, D.S. Zotkin34
1 Argonne National Laboratory, Argonne, Illinois 60439-4815, USA A
2 Andrews University, Berrien Springs, Michigan 49104-0380, USA
3 INFN Bologna, Bologna, Italy B
4 University and INFN Bologna, Bologna, Italy B
5 Physikalisches Institut der Universitat Bonn, Bonn, Germany C
6 H.H. Wills Physics Laboratory, University of Bristol, Bristol, United Kingdom D
7 Panjab University, Department of Physics, Chandigarh, India
8 Calabria University, Physics Department and INFN, Cosenza, Italy B
9 Institute for Universe and Elementary Particles, Chonnam National University, Kwangju, South Korea
10 Jabatan Fizik, Universiti Malaya, 50603 Kuala Lumpur, Malaysia E
11 Nevis Laboratories, Columbia University, Irvington on Hudson, New York 10027, USA F
12 The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland G
13 AGH-University of Science and Technology, Faculty of Physics and Applied Computer Science, Krakow, Poland H
14 Department of Physics, Jagellonian University, Cracow, Poland
15 Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
16 Deutsches Elektronen-Synchrotron DESY, Zeuthen, Germany
17 INFN Florence, Florence, Italy B
18 University and INFN Florence, Florence, Italy B
19 Fakultat fr Physik der Universitat Freiburg i.Br., Freiburg i.Br., Germany
20 School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom D
21 Department of Engineering in Management and Finance, Univ. of the Aegean, Chios, Greece
22 Hamburg University, Institute of Experimental Physics, Hamburg, Germany I
23 Imperial College London, High Energy Nuclear Physics Group, London, United Kingdom D
24 Institute of Particle and Nuclear Studies, KEK, Tsukuba, Japan J
25 Institute of Physics and Technology of Ministry of Education and Science of Kazakhstan, Almaty, Kazakhstan
26 Institute for Nuclear Research, National Academy of Sciences, Kyiv, Ukraine
27 Department of Nuclear Physics, National Taras Shevchenko University of Kyiv, Kyiv, Ukraine
28 Kyungpook National University, Center for High Energy Physics, Daegu, South Korea K
29 Institut de Physique Nuclaire, Universit Catholique de Louvain, Louvain-la-Neuve, Belgium L
30 Departamento de Fsica Terica, Universidad Autnoma de Madrid, Madrid, Spain M
31 Department of Physics, McGill University, Montral, Qubec, Canada H3A 2T8 N
32 Meiji Gakuin University, Faculty of General Education, Yokohama, Japan J
33 Moscow Engineering Physics Institute, Moscow, Russia O
34 Lomonosov Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow, Russia P
35 Max-Planck-Institut fr Physik, Mnchen, Germany
36 NIKHEF and University of Amsterdam, Amsterdam, Netherlands Q
37 Physics Department, Ohio State University, Columbus, Ohio 43210, USA A
38 Department of Physics, University of Oxford, Oxford, United Kingdom D
39 INFN Padova, Padova, Italy B
40 Dipartimento di Fisica dell Universit and INFN, Padova, Italy B
41 Department of Physics, Pennsylvania State University, University Park, Pennsylvania 16802, USA F
34
JHEP05(2013)097
42 Polytechnic University, Tokyo, Japan J
43 Dipartimento di Fisica, Universit La Sapienza and INFN, Rome, Italy B
44 Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, United Kingdom D
45 Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics, Tel Aviv University, Tel Aviv, Israel R
46 Department of Physics, Tokyo Institute of Technology, Tokyo, Japan J
47 Department of Physics, University of Tokyo, Tokyo, Japan J
48 Tokyo Metropolitan University, Department of Physics, Tokyo, Japan J
49 Universit di Torino and INFN, Torino, Italy B
50 Universit del Piemonte Orientale, Novara, and INFN, Torino, Italy B
51 Department of Physics, University of Toronto, Toronto, Ontario, Canada M5S 1A7 N
52 Physics and Astronomy Department, University College London, London, United Kingdom D
53 Faculty of Physics, University of Warsaw, Warsaw, Poland
54 National Centre for Nuclear Research, Warsaw, Poland
55 Department of Particle Physics and Astrophysics, Weizmann Institute, Rehovot, Israel
56 Department of Physics, University of Wisconsin, Madison, Wisconsin 53706, USA A
57 Department of Physics, York University, Ontario, Canada M3J 1P3 N
A supported by the US Department of Energy
B supported by the Italian National Institute for Nuclear Physics (INFN)
C supported by the German Federal Ministry for Education and Research (BMBF), under contractNo. 05 H09PDF
D supported by the Science and Technology Facilities Council, UK
E supported by HIR and UMRG grants from Universiti Malaya, and an ERGS grant from theMalaysian Ministry for Higher Education
F supported by the US National Science Foundation. Any opinion, ndings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reect the views of the National Science Foundation.
G supported by the Polish Ministry of Science and Higher Education as a scientic project No.DPN/N188/DESY/2009
H supported by the Polish Ministry of Science and Higher Education and its grants for ScienticResearch
I supported by the German Federal Ministry for Education and Research (BMBF), under contractNo. 05h09GUF, and the SFB 676 of the Deutsche Forschungsgemeinschaft (DFG)
J supported by the Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT) and its grants for Scientic Research
K supported by the Korean Ministry of Education and Korea Science and Engineering Foundation
L supported by FNRS and its associated funds (IISN and FRIA) and by an Inter-UniversityAttraction Poles Programme subsidised by the Belgian Federal Science Policy Oce
M supported by the Spanish Ministry of Education and Science through funds provided by CICYT
N supported by the Natural Sciences and Engineering Research Council of Canada (NSERC)
O partially supported by the German Federal Ministry for Education and Research (BMBF)
P supported by RF Presidential grant N 3920.2012.2 for the Leading Scientic Schools and by theRussian Ministry of Education and Science through its grant for Scientic Research on High Energy Physics
Q supported by the Netherlands Foundation for Research on Matter (FOM)
R supported by the Israel Science Foundation
a now at University of Salerno, Italy
b now at Queen Mary University of London, United Kingdom
c also funded by Max Planck Institute for Physics, Munich, Germany
d also Senior Alexander von Humboldt Research Fellow at Hamburg University, Institute ofExperimental Physics, Hamburg, Germany
35
JHEP05(2013)097
e also at Cracow University of Technology, Faculty of Physics, Mathematics and Applied ComputerScience, Poland
f supported by the research grant No. 1 P03B 04529 (2005-2008)
g partially supported by the Polish National Science Centre projects DEC-2011/01/B/ST2/03643 andDEC-2011/03/B/ST2/00220
h now at Rockefeller University, New York, NY 10065, USA
i now at DESY group FS-CFEL-1
j now at Institute of High Energy Physics, Beijing, China
k now at DESY group FEB, Hamburg, Germany
l also at Moscow State University, Russia
m now at University of Liverpool, United Kingdom
n now at CERN, Geneva, Switzerland
o also aliated with University College London, UK
p now at Goldman Sachs, London, UK
q also at Institute of Theoretical and Experimental Physics, Moscow, Russia
r also at FPACS, AGH-UST, Cracow, Poland
s partially supported by Warsaw University, Poland
t supported by the Alexander von Humboldt Foundation
u now at Istituto Nazionale di Fisica Nucleare (INFN), Pisa, Italy
v now at Haase Energie Technik AG, Neumnster, Germany
w now at Department of Physics, University of Bonn, Germany
x also aliated with DESY, Germany
y also at University of Tokyo, Japan
z now at Kobe University, Japan
deceased
aa supported by DESY, Germany
ab member of National Technical University of Ukraine, Kyiv Polytechnic Institute, Kyiv, Ukraine
ac member of National Technical University of Ukraine, Kyiv, Ukraine
ad now at DESY ATLAS group
ae member of National University of Kyiv - Mohyla Academy, Kyiv, Ukraine
af Alexander von Humboldt Professor; also at DESY and University of Oxford
ag STFC Advanced Fellow
ah now at LNF, Frascati, Italy
ai This material was based on work supported by the National Science Foundation, while working at the Foundation.
aj also at Max Planck Institute for Physics, Munich, Germany, External Scientic Member
ak now at Tokyo Metropolitan University, Japan
al now at Nihon Institute of Medical Science, Japan
am now at Osaka University, Osaka, Japan
an also at
Ld University, Poland
ao member of
Ld University, Poland
ap now at Department of Physics, Stockholm University, Stockholm, Sweden
36
JHEP05(2013)097
You have requested "on-the-fly" machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Show full disclaimer
Neither ProQuest nor its licensors make any representations or warranties with respect to the translations. The translations are automatically generated "AS IS" and "AS AVAILABLE" and are not retained in our systems. PROQUEST AND ITS LICENSORS SPECIFICALLY DISCLAIM ANY AND ALL EXPRESS OR IMPLIED WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES FOR AVAILABILITY, ACCURACY, TIMELINESS, COMPLETENESS, NON-INFRINGMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Your use of the translations is subject to all use restrictions contained in your Electronic Products License Agreement and by using the translation functionality you agree to forgo any and all claims against ProQuest or its licensors for your use of the translation functionality and any output derived there from. Hide full disclaimer
SISSA, Trieste, Italy 2013
Abstract
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image)
The production of D ^sup *±^ mesons in deep inelastic ep scattering has been measured for exchanged photon virtualities 5<Q ^sup 2^<1000 GeV^sup 2^, using an integrated luminosity of 363 pb^sup -1^ with the ZEUS detector at HERA. Differential cross sections have been measured and compared to next-to-leading-order QCD calculations. The cross-sections are used to extract the charm contribution to the proton structure functions, expressed in terms of the reduced charm cross section, .... Theoretical calculations based on fits to inclusive HERA data are compared to the results.
You have requested "on-the-fly" machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Show full disclaimer
Neither ProQuest nor its licensors make any representations or warranties with respect to the translations. The translations are automatically generated "AS IS" and "AS AVAILABLE" and are not retained in our systems. PROQUEST AND ITS LICENSORS SPECIFICALLY DISCLAIM ANY AND ALL EXPRESS OR IMPLIED WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES FOR AVAILABILITY, ACCURACY, TIMELINESS, COMPLETENESS, NON-INFRINGMENT, MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Your use of the translations is subject to all use restrictions contained in your Electronic Products License Agreement and by using the translation functionality you agree to forgo any and all claims against ProQuest or its licensors for your use of the translation functionality and any output derived there from. Hide full disclaimer