Study of ... production and cold nuclear matter effects in pPb collisions at ... = 5 TeV

Abstract

Abstract

Production of ... mesons in proton-lead collisions at a nucleon-nucleon centre-of-mass energy ... = 5 TeV is studied with the LHCb detector. The analysis is based on a data sample corresponding to an integrated luminosity of 1.6 nb^-1. The ... mesons of transverse momenta up to 15 GeV/c are reconstructed in the dimuon decay mode. The rapidity coverage in the centre-of-mass system is 1.5 < y < 4.0 (forward region) and -5.0 < y < -2.5 (backward region). The forward-backward production ratio and the nuclear modification factor for ...(1S) mesons are determined. The data are compatible with the predictions for a suppression of ...(1S) production with respect to proton-proton collisions in the forward region, and an enhancement in the backward region. The suppression is found to be smaller than in the case of prompt J/[psi] mesons. [Figure not available: see fulltext.]

Published for SISSA by Springer

Received: May 21, 2014

Accepted: July 2, 2014 Published: July 21, 2014

Study of production and cold nuclear matter e ects in pPb collisions at psNN = 5 TeV

JHEP07(2014)094

The LHCb collaboration

E-mail: mailto:[email protected]

Web End [email protected]

Abstract: Production of mesons in proton-lead collisions at a nucleon-nucleon centreof-mass energy psNN = 5 TeV is studied with the LHCb detector. The analysis is based on a data sample corresponding to an integrated luminosity of 1.6 nb1. The mesons of transverse momenta up to 15 GeV/c are reconstructed in the dimuon decay mode. The rapidity coverage in the centre-of-mass system is 1.5 < y < 4.0 (forward region) and 5.0 <

y < 2.5 (backward region). The forward-backward production ratio and the nuclear

modication factor for (1S) mesons are determined. The data are compatible with the predictions for a suppression of (1S) production with respect to proton-proton collisions in the forward region, and an enhancement in the backward region. The suppression is found to be smaller than in the case of prompt J/ mesons.

Keywords: Relativistic heavy ion physics, Quarkonium, Heavy quark production, Heavy Ions, Particle and resonance production

ArXiv ePrint: 1405.5152

Open Access, Copyright CERN,for the benet of the LHCb Collaboration. Article funded by SCOAP3.

doi:http://dx.doi.org/10.1007/JHEP07(2014)094

Web End =10.1007/JHEP07(2014)094

Contents

1 Introduction 1

2 Detector and data set 2

3 Cross-section determination 3

4 Systematic uncertainties 5

5 Results 6

6 Conclusions 8

The LHCb collaboration 14

JHEP07(2014)094

1 Introduction

Heavy quarkonia are produced at the early stage of ultra-relativistic heavy-ion collisions and probe the existence of the quark-gluon plasma (QGP), a hot and dense nuclear medium. Due to colour screening e ects in the QGP, the yield of heavy quarkonia in heavy-ion collisions is expected to be suppressed with respect to proton-proton (pp) collisions [1]. Heavy quarkonium production can also be suppressed by normal nuclear matter e ects, often referred to as cold nuclear matter (CNM) e ects, such as nuclear shadowing (antishadowing) e ects, energy loss of the heavy quark or the heavy quark pair in the medium or nuclear absorption. Shadowing and antishadowing e ects [26] describe how the parton densities are modied when a nucleon is bound inside a nucleus. A coherent treatment of energy loss for the inital state partons and nal state cc or bb pairs in nuclear matter is described in refs. [7, 8]. Nuclear absorption is a nal-state e ect caused by the break-up of these pairs due to the inelastic scattering with the nucleons. The importance of studying absorption e ects for quarkonia in the high energy heavy-ion proton collisions is discussed in refs. [911], and the energy and rapidity dependence was studied in ref. [12]. The main models describing quarkonium production in hadron collisions are the colour-singlet model (CSM) [1316], the colour-evaporation model (CEM) [17] and non-relativistic quantum chromodynamics (NRQCD) [1821].

The pA collisions in which a QGP is not expected to be created, provide a unique opportunity to study CNM e ects and to constrain the nuclear parton distribution functions describing the partonic structure of matter. These measurements o er crucial information to disentangle CNM e ects from the e ects of QGP in nucleus-nucleus collisions. Several measurements of CNM e ects were performed by the xed-target experiments at the SPS [2225], Fermilab [26] and DESY [27]. With the proton-lead (pPb) data collected

1

in 2013, CNM e ects have been studied by the LHCb experiment with measurements of the di erential production cross-sections of prompt J/ mesons and J/ from b-hadron decays [28], and by the ALICE experiment using measurements of inclusive J/ production [29]. Unambiguous CNM e ects have been observed, in agreement with theoretical predictions.

The study of bottomonia, (1S), (2S) and (3S) mesons, denoted generically by in the following, provides complementary information about CNM e ects to that from J/ production. For example, the (1S) meson can survive in the QGP at higher temperatures than other heavy quarkonia owing to its higher binding energy [30, 31]. As a consequence, based on the prediction that the dissociation of states in the QGP occurs sequentially according to their di erent binding energies [31], it is interesting to determine the production ratios of excited mesons,

RnS/1S

( (nS)) B( (nS) ! [notdef]+[notdef])

( (1S)) B( (1S) ! [notdef]+[notdef])

JHEP07(2014)094

, n = 2, 3, (1.1)

where represents the cross-section for the production of the indicated meson and B

represents the branching fraction for its dimuon decay mode. The production ratios RnS/1S

have been measured in pPb [32] and PbPb [33] collisions for central rapidities by the CMS experiment and the ratios of these quantities to RnS/1S measured in pp collisions show clear sequential suppression of production, which indicates stronger (cold or hot) nuclear matter e ects on the excited states. LHCb can extend those studies to the forward and backward rapidity regions. From the theoretical point of view, predictions for bottomonia are more reliable than those for charmonia owing to the heavier quark masses and lower quark velocities.

In this analysis, the inclusive production cross-sections of mesons are measured in pPb collisions at a nucleon-nucleon centre-of-mass energy psNN = 5 TeV at LHCb. Based

on the cross-section measurements, the production ratios RnS/1S are evaluated and the CNM e ects for (1S) mesons are studied. The LHCb detector is a single-arm forward spectrometer [34] that covers the pseudorapidity region 2 < < 5 in pp collisions. To allow for measurements of pA collisions at both positive and negative rapidity, where rapidity is dened with respect to the direction of the proton, the proton and lead beams were interchanged approximately halfway during the pPb data taking period. Owing to the asymmetry in the energy per nucleon in the two beams, the nucleon-nucleon centre-of-mass system has a rapidity of +0.465 (0.465) in the laboratory frame for the forward

(backward) collisions, where forward (backward) is dened as positive (negative) rapidity. For the measurements described here rapidity ranges of 1.5 < y < 4.0 and 5.0 < y < 2.5

are studied.

2 Detector and data set

The LHCb detector [34] is designed for the study of particles containing b or c quarks. The detector includes a high-precision tracking system consisting of a silicon-strip vertex detector (VELO) surrounding the interaction region, a large-area silicon-strip detector located

2

upstream of a dipole magnet with a bending power of about 4 Tm, and three stations of silicon-strip detectors and straw drift tubes [35] placed downstream of the magnet. The combined tracking system provides a momentum resolution with a relative uncertainty that varies from 0.4% at low momentum to 0.6% at 100 GeV/c, and an impact parameter measurement with a resolution of 20 m for charged particles with large transverse momentum, pT. Di erent types of charged hadrons are distinguished using information from two ring-imaging Cherenkov (RICH) detectors [36]. Photon, electron and hadron candidates are identied by a calorimeter system consisting of scintillating-pad and preshower detectors, an electromagnetic calorimeter and a hadronic calorimeter. Muons are identied by a system composed of alternating layers of iron and multiwire proportional chambers [37]. The trigger [38] consists of a hardware stage, based on information from the calorimeter and muon systems, followed by a software stage, which applies a full event reconstruction.

The data sample used for this analysis was acquired during the pPb run in early 2013 and corresponds to an integrated luminosity of 1.1 nb1 (0.5 nb1) for forward (backward) collisions. The hardware trigger was employed as an interaction trigger that rejected empty events. The software trigger required one well-reconstructed charged particle with hits in the muon system and a transverse momentum greater than 600 MeV/c.

Simulated samples based on pp collisions at 8 TeV are reweighted according to the track multiplicity to reproduce the experimental data at 5 TeV. The e ect of the asymmetric beam energies in pPb collisions and di erent detector occupancies have been taken into account for the determination of the e ciencies. In the simulation, pp collisions are generated using Pythia 6.4 [39] with a specic LHCb conguration [40]. Hadron decays are described by EvtGen [41], where nal-state radiation is generated using Photos [42]. The interactions of the generated particles with the detector and its response are implemented using the Geant4 toolkit [43, 44] as described in ref. [45].

3 Cross-section determination

The total cross-section is measured for (1S), (2S) and (3S) mesons in the kinematic region pT < 15 GeV/c and 1.5 < y < 4.0 (5.0 < y < 2.5) for the forward (backward)

sample. The cross-section is also measured in the common rapidity coverage of the forward and backward samples, 2.5 < |y| < 4.0, to study CNM e ects. The product of the total

production cross-sections and the branching fractions for (nS) mesons is given by

( (nS)) B( (nS) ! [notdef]+[notdef]) =

Ncor( (nS) ! [notdef]+[notdef])

L

JHEP07(2014)094

, n = 1, 2, 3, (3.1)

where Ncor( (nS) ! [notdef]+[notdef]) is the e ciency-corrected number of signal candidates recon

structed with dimuon nal states in the given pT and y region, and L is the integrated

luminosity, calibrated by means of van der Meer scans [28, 46] for each beam conguration separately.

The strategy for the cross-section measurement follows refs. [4749]. The candidates are reconstructed from two oppositely charged particles consistent with a muon hypothesis based on particle identication information from the RICH detectors, the calorime-

3

2

Candidates per 60 MeV/c

2

Candidates per 60 MeV/c

120

100

80

60

40

20

0

LHCb

90

80

LHCb

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0

9000 10000 11000

+

9000 10000 11000

JHEP07(2014)094

m

m

- [MeV/c

- [MeV/c

2

2

]

Figure 1. Invariant mass distribution of [notdef]+[notdef] pairs in the (left) forward and (right) backward samples of pPb collisions. The transverse momentum range is pT < 15 GeV/c. The rapidity range is 1.5 < y < 4.0 (5.0 < y < 2.5) for the forward (backward) sample. The black dots are

the data points, the blue dashed curve indicates the signal component, the green dotted curve represents the combinatorial background, and the red solid curve is the sum of the signal and background components.

ters and the muon system. Each particle must have a pT above 1 GeV/c and a good track t quality. The two muon candidates are required to originate from a common vertex.

An unbinned extended maximum likelihood t to the invariant mass distribution of the selected candidates is performed to determine the signal yields of (1S), (2S) and (3S) mesons in a t range 8400 < m+ < 11400 MeV/c2. To describe the (1S), (2S)

and (3S) signal components, a sum of three Crystal Ball (CB) functions [50] is used, while the combinatorial background is modelled with an exponential function.

The shape parameters of the CB functions have been xed using large samples collected in pp collisions [48], which determine the mass resolution for the (1S) to be 43.0 MeV/c2.

The resolutions for the (2S) and (3S) signals are obtained by scaling this value by the ratio of their masses to the (1S) meson mass [51].

Figure 1 shows the dimuon invariant mass distributions in the pPb forward and backward samples, with the t results superimposed. In the backward sample higher combinatorial background is observed due to the larger track multiplicity. The signal yields obtained from the t are N (1S) = 189 16 (72 14), N (2S) = 41 9 (17 10), and

N (3S) = 137 (48) in the forward (backward) sample. The yields of (1S) mesons with

2.5 < |y| < 4.0 are 122 13 in the forward sample and 70 13 in the backward sample.

The uncertainties are statistical only.

A signal weight factor, !i, is assigned to each candidate using the sPlot technique [52] with the dimuon invariant mass as the discriminating variable. The e ciency-corrected signal yield Ncor is then calculated through an event-by-event e ciency correction [epsilon1]i as

Ncor =

Xi!i/[epsilon1]i, (3.2)

where the sum runs over all events. The total signal e ciency, which depends on the pT and y of the mesons, is the product of the geometric acceptance, reconstruction and

4

+

]

selection, muon identication, and trigger e ciencies. The product of the acceptance, reconstruction and selection e ciencies is determined in ne pT and y bins with simulated samples. The simulated events are reweighted according to the track multiplicity observed in data and corrected to account for small di erences in the track-reconstruction e ciency between data and simulation [53, 54]. In the selected rapidity range the reconstruction and selection e ciency varies between 30% and 81%. The muon identication e ciency is obtained as a function of momentum and transverse momentum by a data-driven tagand-probe approach using a J/ ! [notdef]+[notdef] sample [53]. For candidates this e ciency is

generally larger than 90%. The trigger e ciency was determined using a sample of (1S) decays into muon pairs that did not require the muons to be in the trigger, and is around 95%. The corresponding uncertainty is described in the following section. Here the much more abundant J/ decays are not used since the trigger e ciency depends on the muon transverse momentum.

4 Systematic uncertainties

The systematic uncertainties of this analysis are summarised in table 1. They are added in quadrature to obtain the total systematic uncertainty.

Due to the nite size of the J/ calibration sample, the systematic uncertainty of the muon identication e ciency obtained from the tag-and-probe approach is 1.3%. The uncertainty due to the track reconstruction e ciency is estimated to be 1.5% by varying within its uncertainty the correction applied to the muon reconstruction e ciency.

The systematic uncertainty due to the choice of the t model used to describe the shape of the dimuon mass distribution is estimated by varying the xed parameters of the CB function, or by using a polynomial function, whose parameters are determined by the t, to describe the background shape. The largest di erence in yields of each resonance with respect to the nominal result is considered as the systematic uncertainty.

The luminosity is determined with an uncertainty of 1.9% (2.1%) for the pPb forward (backward) sample from the rate of interactions that yield at least one reconstructed track in the VELO. The absolute calibration is determined with van der Meer scans, as described in ref. [28].

The trigger e ciency in the forward sample is determined directly from the data using a sample unbiased by the trigger decision. The corresponding uncertainty is 2.1%. Due to the limited sample size, the trigger e ciency in the backward sample is estimated using the forward sample, since it has been observed that the dependence of trigger e ciencies on the charged-particle multiplicity is small [28]. The systematic uncertainty is 5.0%, taking into account the di erence between the trigger e ciencies obtained using the forward and backward samples.

An uncertainty is introduced by the possible di erence between the data and simulation samples of the pT and y spectra inside each bin. This is estimated by doubling the number of pT or y bins in the e ciency tables based on the simulated samples. In the forward (backward) sample, the di erence to the nominal binning is 3.9% (7.6%) in the full rapidity

5

JHEP07(2014)094

Forward Backward

Source (1S) (2S) (3S) (1S) (2S) (3S) Muon identication 1.3 1.3 1.3 1.3 1.3 1.3 Tracking e ciency 1.5 1.5 1.5 1.5 1.5 1.5 Mass t model 1.1 (1.0) 4.9 13 1.8 (1.7) 19 90 Luminosity 1.9 1.9 1.9 2.1 2.1 2.1 Trigger 2.1 2.1 2.1 5.0 5.0 5.0 MC generation kinematics 3.9 (3.8) 3.9 3.9 7.6 (6.3) 7.6 7.6 Reconstruction 1.5 1.5 1.5 1.5 1.5 1.5 Total 5.5 (5.4) 7.3 14 9.8 (8.8) 21 91

Table 1. Relative systematic uncertainties on the cross-sections, in percent, in the full rapidity range. The values in parenthesis refer specically to (1S) measurements when systematic uncertainties in the common rapidity range 2.5 < |y| < 4.0 are notably di erent.

range, and 3.8% (6.3%) in the common rapidity coverage. These di erences are taken as

systematic uncertainties.

The systematic uncertainties due to reconstruction e ects, e.g. track and vertexing quality, have been studied in the J/ analysis in pPb collisions [28] and determined to be 1.5%.

Although the initial polarisation of the vector meson a ects the e ciency, recent results show that the polarisations of the (1S), (2S) and (3S) mesons are small in pp collisions [55]. In this analysis, we take them to be zero and do not assign any systematic uncertainty to account for this assumption.

5 Results

The products of production cross-sections and branching fractions for mesons with pT <

15 GeV/c are measured for the di erent rapidity ranges to be

( (1S), 5.0 < y < 2.5) B(1S) = 295 56 29 nb,

( (2S), 5.0 < y < 2.5) B(2S) = 81 39 18 nb,

( (3S), 5.0 < y < 2.5) B(3S) = 5 26 5 nb,

( (1S), 1.5 < y < 4.0) B(1S) = 380 35 21 nb,

( (2S), 1.5 < y < 4.0) B(2S) = 75 19 5 nb,

( (3S), 1.5 < y < 4.0) B(3S) = 27 16 4 nb,where the rst uncertainty is statistical and the second systematic, a convention also used in the following. The variation in relative size of the statistical uncertainty compared to the signal yields is due to the variation of the event-by-event e ciencies and the variation of the signal-to-background ratio over the accessible phase space. In the common rapidity

6

JHEP07(2014)094

range 2.5 < |y| < 4.0, the results for (1S) production are( (1S), 4.0 < y < 2.5) B(1S) = 282 53 25 nb,

( (1S), 2.5 < y < 4.0) B(1S) = 211 23 11 nb.

Using the results described above, the production ratios RnS/1S are measured to be

R2S/1S(5.0 < y < 2.5) = 0.28 0.14 0.05,

R3S/1S(5.0 < y < 2.5) = 0.02 0.09 0.02,

R2S/1S( 1.5 < y < 4.0) = 0.20 0.05 0.01,

R3S/1S( 1.5 < y < 4.0) = 0.07 0.04 0.01.

In these ratios all the systematic uncertainties cancel except for those due to the mass t model. The measurements of RnS/1S in pPb collisions are compatible with those in pp collisions [4749].

The nuclear modication factor RpPb(psNN ) pPb(ps

NN )/(A pp(ps

NN )) is used

to study the CNM e ects, where A is the atomic mass number of the nucleus and psNN

is the centre-of-mass energy of the nucleon-nucleon system. The determination of RpPb

requires the value of the production cross-section in pp collisions at 5 TeV, for which no data is yet available. Following the same approach as in the measurement of RpPb for J/

mesons [28], this cross-section is obtained by a power-law interpolation from previous LHCb measurements [4749] in the range pT < 15 GeV/c and 2.5 < y < 4.0 [56]. The product of the production cross-section and the dimuon branching fraction for (1S) mesons in pp collisions at 5 TeV, with pT < 15 GeV/c and 2.5 < y < 4.0, is pp B(1S) = 1.12 0.11 nb,

from which the nuclear modication factors RpPb for (1S) mesons in the ranges 4.0 <

y < 2.5 and 2.5 < y < 4.0 are determined to be

RpPb( (1S), 4.0 < y < 2.5) = 1.21 0.23 0.12,

RpPb( (1S), 2.5 < y < 4.0) = 0.90 0.10 0.09.

Figure 2 shows the measurement of RpPb for (1S) mesons as a function of rapidity. Relative to the (1S) production in pp collisions, the data are consistent with a suppression in the forward region and an enhancement due to antishadowing e ects in the backward hemisphere. In the forward region, the data suggest that the suppression of (1S) production is smaller than that of prompt J/ production. The central value of RpPb for (1S)

mesons is close to that for J/ from b-hadron decays, which reects the CNM e ects on b hadrons. Within the sizable uncertainties of the current measurements, the result agrees with existing theoretical predictions [3, 6, 7]. The calculations in ref. [6] are based on the leading-order CSM, taking into account the modication of the gluon distribution functions in the nucleus with the parameterisation EPS09 [57]. The predictions in ref. [3] use the next-to-leading-order CEM and the parton shadowing is calculated with the EPS09 parameterisation. Theoretical predictions of the coherent energy loss e ect are provided in ref. [7], both with and without additional parton shadowing e ects as parameterised with EPS09.

7

JHEP07(2014)094

pPb

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EPS09 at LO in Ref.[6]

(1S)

U

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U

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EPS09 at NLO in Ref.[3]

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Prompt J/

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JHEP07(2014)094

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Energy loss in Ref.[7]

(1S)

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E.loss+EPS09 NLO in Ref.[7]

(1S)

U

y

0.2

0.2

Prompt J/

Prompt J/

0 -4 -2 0 2 4

0 -4 -2 0 2 4

y

y

Figure 2. Nuclear modication factor, RpPb, compared to other measurements and theoretical predictions. The black dots, red squares, and blue triangles indicate the LHCb measurements for (1S) mesons, prompt J/ mesons, and J/ from b-hadron decays, respectively [28]. The inner error bars (delimited by the horizontal lines) show the statistical uncertainties; the outer ones show the statistical and systematic uncertainties added in quadrature. The data are compared with theoretical predictions for and prompt J/ mesons from di erent models, one per panel. The shaded areas indicate the uncertainties of the theoretical calculations.

Another observable that characterises CNM e ects is the forward-backward production ratio, dened as RFB(psNN , |y|) (ps

NN , +|y|)/(ps

NN , |y|). The ratio does not depend

on the reference pp cross-section, and part of the experimental and theoretical uncertainties cancel. The forward-backward production ratio of (1S) mesons is

RFB(2.5 < |y| < 4.0) = 0.75 0.16 0.08.

Figure 3 shows the measured value of RFB for (1S) mesons as a function of absolute rapidity, together with the theoretical predictions [3, 6, 7] and RFB, measured by LHCb, for prompt J/ mesons and J/ from b hadrons [28]. Measurements and theoretical predictions agree.

6 Conclusions

The production of mesons is studied in pPb collisions with the LHCb detector at a nucleon-nucleon centre-of-mass energy psNN = 5 TeV in the transverse momentum range of pT < 15 GeV/c and rapidity range 5.0 < y < 2.5 and 1.5 < y < 4.0.

8

FB

R

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LHCb

FB

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pPb

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= 5 TeV

NN

pPb

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= 5 TeV

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1

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LHCb,

U

(1S)

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EPS09 at LO in Ref.[9]

(1S)

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EPS09 at NLO in Ref.[4]

(1S)

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y

Prompt J/

Prompt J/

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0 0 1 2 3 4 5

0 0 1 2 3 4 5

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JHEP07(2014)094

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pPb

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Energy loss in Ref.[3]

(1S)

U

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E.loss+EPS09 NLO in Ref.[3]

(1S)

U

y

Prompt J/

Prompt J/

0 0 1 2 3 4 5

0 0 1 2 3 4 5

|y|

|y|

Figure 3. Forward-backward production ratio, RFB, as a function of absolute rapidity. The black dots, red squares, and blue triangles indicate the LHCb measurements for (1S) mesons, prompt J/ mesons, and J/ from b-hadron decays, respectively [28]. The inner error bars (delimited by the horizontal lines) show the statistical uncertainties; the outer ones show the statistical and systematic uncertainties added in quadrature. The data are compared with theoretical predictions for and prompt J/ mesons from di erent models, one per panel. The shaded areas indicate the uncertainties of the theoretical calculations.

The nuclear modication factor for the (1S) meson is determined using the cross-section of (1S) production in pp collisions at 5 TeV interpolated from previous LHCb measurements. It is compatible with predictions of a suppression of (1S)production with respect to pp collisions in the forward region and antishadowing e ects in the backward region. The forward-backward production ratio of the (1S) is also measured, and the result is consistent with existing theoretical predictions, where the nuclear shadowing effects are taken into account with the EPS09 parameterisation, or a coherent energy loss is considered. A rst measurement of the production ratios of excited mesons relative to the ground state has been performed. Due to the small integrated luminosity of the available data sample, the measurements presented here, though very promising, have relatively large uncertainties. More pPb data would allow a precise quantitative investigation of cold nuclear matter e ects, to establish a reliable baseline for the interpretations of related quark-gluon plasma signatures in nucleus-nucleus collisions and constrain the parameterisations of theoretical models.

9

Acknowledgments

We thank F. Arleo, J. P. Lansberg and R. Vogt for providing us with the theoretical predictions and for the stimulating and helpful discussions. We express our gratitude to our colleagues in the CERN accelerator departments for the excellent performance of the LHC. We thank the technical and administrative sta at the LHCb institutes. We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); NSFC (China); CNRS/IN2P3 and Region Auvergne (France); BMBF, DFG, HGF and MPG (Germany); SFI (Ireland); INFN (Italy); FOM and NWO (The Netherlands); SCSR (Poland); MEN/IFA (Romania); MinES, Rosatom, RFBR and NRC Kurchatov Institute (Russia); MinECo, XuntaGal and GENCAT (Spain); SNSF and SER (Switzerland); NASU (Ukraine); STFC and the Royal Society (United Kingdom); NSF (U.S.A.). We also acknowledge the support received from EPLANET, Marie Curie Actions and the ERC under FP7. The Tier1 computing centres are supported by IN2P3 (France), KIT and BMBF (Germany), INFN (Italy), NWO and SURF (The Netherlands), PIC (Spain), GridPP (United Kingdom). We are indebted to the communities behind the multiple open source software packages on which we depend. We are also thankful for the computing resources and the access to software R&D tools provided by Yandex LLC (Russia).

Open Access. This article is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/

Web End =CC-BY 4.0 ), which permits any use, distribution and reproduction in any medium, provided the original author(s) and source are credited.

References

[1] T. Matsui and H. Satz, J/ suppression by quark-gluon plasma formation, http://dx.doi.org/10.1016/0370-2693(86)91404-8

Web End =Phys. Lett. B 178 http://dx.doi.org/10.1016/0370-2693(86)91404-8

Web End =(1986) 416 [http://inspirehep.net/search?p=find+J+Phys.Lett.,B178,416

Web End =INSPIRE ].

[2] E.G. Ferreiro, F. Fleuret, J.P. Lansberg and A. Rakotozandrabe, Impact of the nuclear modication of the gluon densities on J/ production in pPb collisions at psNN = 5 TeV,

http://dx.doi.org/10.1103/PhysRevC.88.047901

Web End =Phys. Rev. C 88 (2013) 047901 [http://arxiv.org/abs/1305.4569

Web End =arXiv:1305.4569 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1305.4569

Web End =INSPIRE ].

[3] J.L. Albacete et al., Predictions for p+Pb collisions at psNN = 5 TeV, http://dx.doi.org/10.1142/S0218301313300075

Web End =Int. J. Mod. Phys. E http://dx.doi.org/10.1142/S0218301313300075

Web End =22 (2013) 1330007 [http://arxiv.org/abs/1301.3395

Web End =arXiv:1301.3395 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1301.3395

Web End =INSPIRE ].

[4] A. Adeluyi and T. Nguyen, Coherent photoproduction of and mesons in ultraperipheral pPb and PbPb collisions at the CERN Large Hadron Collider at pSNN = 5 TeV and

pSNN = 2.76 TeV, http://dx.doi.org/10.1103/PhysRevC.87.027901

Web End =Phys. Rev. C 87 (2013) 027901 [http://arxiv.org/abs/1302.4288

Web End =arXiv:1302.4288 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1302.4288

Web End =INSPIRE ].

[5] G.A. Chirilli, B.-W. Xiao and F. Yuan, Inclusive hadron productions in pA collisions, http://dx.doi.org/10.1103/PhysRevD.86.054005

Web End =Phys. http://dx.doi.org/10.1103/PhysRevD.86.054005

Web End =Rev. D 86 (2012) 054005 [http://arxiv.org/abs/1203.6139

Web End =arXiv:1203.6139 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1203.6139

Web End =INSPIRE ].

[6] E.G. Ferreiro, F. Fleuret, J.P. Lansberg, N. Matagne and A. Rakotozandrabe, production in p(d)A collisions at RHIC and the LHC, http://dx.doi.org/10.1140/epjc/s10052-013-2427-5

Web End =Eur. Phys. J. C 73 (2011) 2427 [http://arxiv.org/abs/1110.5047

Web End =arXiv:1110.5047 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1110.5047

Web End =INSPIRE ].

[7] F. Arleo and S. Peign, Heavy-quarkonium suppression in p-A collisions from parton energy loss in cold QCD matter, http://dx.doi.org/10.1007/JHEP03(2013)122

Web End =JHEP 03 (2013) 122 [http://arxiv.org/abs/1212.0434

Web End =arXiv:1212.0434 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1212.0434

Web End =INSPIRE ].

10

JHEP07(2014)094

[8] F. Arleo, R. Kolevatov, S. Peign and M. Rustamova, Centrality and p? dependence of J/

suppression in proton-nucleus collisions from parton energy loss, http://dx.doi.org/10.1007/JHEP05(2013)155

Web End =JHEP 05 (2013) 155 [http://arxiv.org/abs/1304.0901

Web End =arXiv:1304.0901 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1304.0901

Web End =INSPIRE ].

[9] D. Kharzeev and H. Satz, Charmonium composition and nuclear suppression, http://dx.doi.org/10.1016/0370-2693(95)01328-8

Web End =Phys. Lett. B http://dx.doi.org/10.1016/0370-2693(95)01328-8

Web End =366 (1996) 316 [http://arxiv.org/abs/hep-ph/9508276

Web End =hep-ph/9508276 ] [http://inspirehep.net/search?p=find+EPRINT+hep-ph/9508276

Web End =INSPIRE ].

[10] D. Kharzeev and H. Satz, Charmonium interaction in nuclear matter, http://dx.doi.org/10.1016/0370-2693(95)00798-P

Web End =Phys. Lett. B 356 http://dx.doi.org/10.1016/0370-2693(95)00798-P

Web End =(1995) 365 [http://arxiv.org/abs/hep-ph/9504397

Web End =hep-ph/9504397 ] [http://inspirehep.net/search?p=find+EPRINT+hep-ph/9504397

Web End =INSPIRE ].

[11] D. Kharzeev, C. Loureno, M. Nardi and H. Satz, A quantitative analysis of charmonium suppression in nuclear collisions, http://dx.doi.org/10.1007/s002880050392

Web End =Z. Phys. C 74 (1997) 307 [http://arxiv.org/abs/hep-ph/9612217

Web End =hep-ph/9612217 ] [http://inspirehep.net/search?p=find+EPRINT+hep-ph/9612217

Web End =INSPIRE ].

[12] C. Loureno, R. Vogt and H.K. Whri, Energy dependence of J/ absorption in proton-nucleus collisions, http://dx.doi.org/10.1088/1126-6708/2009/02/014

Web End =JHEP 02 (2009) 014 [http://arxiv.org/abs/0901.3054

Web End =arXiv:0901.3054 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:0901.3054

Web End =INSPIRE ].

[13] C.-H. Chang, Hadronic production of J/ associated with a gluon, http://dx.doi.org/10.1016/0550-3213(80)90175-3

Web End =Nucl. Phys. B 172 (1980) http://dx.doi.org/10.1016/0550-3213(80)90175-3

Web End =425 [http://inspirehep.net/search?p=find+J+Nucl.Phys.,B172,425

Web End =INSPIRE ].

[14] R. Baier and R. Rckl, Hadronic production of J/ and : transverse momentum distributions, http://dx.doi.org/10.1016/0370-2693(81)90636-5

Web End =Phys. Lett. B 102 (1981) 364 [http://inspirehep.net/search?p=find+J+Phys.Lett.,B102,364

Web End =INSPIRE ].

[15] J.M. Campbell, F. Maltoni and F. Tramontano, QCD corrections to J/ and production at hadron colliders, http://dx.doi.org/10.1103/PhysRevLett.98.252002

Web End =Phys. Rev. Lett. 98 (2007) 252002 [http://arxiv.org/abs/hep-ph/0703113

Web End =hep-ph/0703113 ] [http://inspirehep.net/search?p=find+EPRINT+hep-ph/0703113

Web End =INSPIRE ].

[16] P. Artoisenet, J.M. Campbell, J.P. Lansberg, F. Maltoni and F. Tramontano, production at Fermilab Tevatron and LHC energies, http://dx.doi.org/10.1103/PhysRevLett.101.152001

Web End =Phys. Rev. Lett. 101 (2008) 152001 [http://arxiv.org/abs/0806.3282

Web End =arXiv:0806.3282 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:0806.3282

Web End =INSPIRE ].

[17] M. Glck, J.F. Owens and E. Reya, Gluon contribution to hadronic J/ production, http://dx.doi.org/10.1103/PhysRevD.17.2324

Web End =Phys. http://dx.doi.org/10.1103/PhysRevD.17.2324

Web End =Rev. D 17 (1978) 2324 [http://inspirehep.net/search?p=find+J+Phys.Rev.,D17,2324

Web End =INSPIRE ].

[18] G.T. Bodwin, E. Braaten and G.P. Lepage, Rigorous QCD analysis of inclusive annihilation and production of heavy quarkonium, http://dx.doi.org/10.1103/PhysRevD.55.5853

Web End =Phys. Rev. D 51 (1995) 1125 [Erratum ibid. D 55 (1997) 5853] [http://arxiv.org/abs/hep-ph/9407339

Web End =hep-ph/9407339 ] [http://inspirehep.net/search?p=find+EPRINT+hep-ph/9407339

Web End =INSPIRE ].

[19] G.T. Bodwin, E. Braaten and G.P. Lepage, Rigorous QCD analysis of inclusive annihilation and production of heavy quarkonium, http://dx.doi.org/10.1103/PhysRevD.55.5853

Web End =Phys. Rev. D 51 (1995) 1125 [Erratum ibid. D 55 (1997) 5853] [http://arxiv.org/abs/hep-ph/9407339

Web End =hep-ph/9407339 ] [http://inspirehep.net/search?p=find+Phys.Rev.,D55,5853

Web End =INSPIRE ].

[20] P.L. Cho and A.K. Leibovich, Color octet quarkonia production, http://dx.doi.org/10.1103/PhysRevD.53.150

Web End =Phys. Rev. D 53 (1996) 150 [http://arxiv.org/abs/hep-ph/9505329

Web End =hep-ph/9505329 ] [http://inspirehep.net/search?p=find+EPRINT+hep-ph/9505329

Web End =INSPIRE ].

[21] P.L. Cho and A.K. Leibovich, Color octet quarkonia production. 2., http://dx.doi.org/10.1103/PhysRevD.53.6203

Web End =Phys. Rev. D 53 (1996) http://dx.doi.org/10.1103/PhysRevD.53.6203

Web End =6203 [http://arxiv.org/abs/hep-ph/9511315

Web End =hep-ph/9511315 ] [http://inspirehep.net/search?p=find+EPRINT+hep-ph/9511315

Web End =INSPIRE ].

[22] NA38 collaboration, M.C. Abreu et al., Charmonia production in 450 GeV/c proton induced reactions, http://dx.doi.org/10.1016/S0370-2693(98)01398-7

Web End =Phys. Lett. B 444 (1998) 516 [http://inspirehep.net/search?p=find+J+Phys.Lett.,B444,516

Web End =INSPIRE ].

[23] NA50 collaboration, B. Alessandro et al., J/ and [prime] production and their normal nuclear absorption in proton-nucleus collisions at 400 GeV, http://dx.doi.org/10.1140/epjc/s10052-006-0079-4

Web End =Eur. Phys. J. C 48 (2006) 329 [http://arxiv.org/abs/nucl-ex/0612012

Web End =nucl-ex/0612012 ] [http://inspirehep.net/search?p=find+EPRINT+nucl-ex/0612012

Web End =INSPIRE ].

[24] NA51 collaboration, M.C. Abreu et al., J/ , [prime] and Drell-Yan production in p p and p d interactions at 450 GeV/c, http://dx.doi.org/10.1016/S0370-2693(98)01014-4

Web End =Phys. Lett. B 438 (1998) 35 [http://inspirehep.net/search?p=find+J+Phys.Lett.,B438,35

Web End =INSPIRE ].

[25] NA60 collaboration, R. Arnaldi et al., J/ production in proton-nucleus collisions at 158 and 400 GeV, http://dx.doi.org/10.1016/j.physletb.2011.11.042

Web End =Phys. Lett. B 706 (2012) 263 [http://arxiv.org/abs/1004.5523

Web End =arXiv:1004.5523 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1004.5523

Web End =INSPIRE ].

11

JHEP07(2014)094

[26] NuSea collaboration, M.J. Leitch et al., Measurement of J/ and [prime] suppression in p-A collisions at 800 GeV/c, http://dx.doi.org/10.1103/PhysRevLett.84.3256

Web End =Phys. Rev. Lett. 84 (2000) 3256 [http://arxiv.org/abs/nucl-ex/9909007

Web End =nucl-ex/9909007 ] [http://inspirehep.net/search?p=find+EPRINT+nucl-ex/9909007

Web End =INSPIRE ].

[27] HERA-B collaboration, I. Abt et al., Kinematic distributions and nuclear e ects of J/ production in 920 GeV xed-target proton-nucleus collisions, http://dx.doi.org/10.1140/epjc/s10052-009-0965-7

Web End =Eur. Phys. J. C 60 (2009) 525 [http://arxiv.org/abs/0812.0734

Web End =arXiv:0812.0734 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:0812.0734

Web End =INSPIRE ].

[28] LHCb collaboration, Study of J/ production and cold nuclear matter e ects in pP b collisions at psNN = 5 TeV, http://dx.doi.org/10.1007/JHEP02(2014)072

Web End =JHEP 02 (2014) 072 [http://arxiv.org/abs/1308.6729

Web End =arXiv:1308.6729 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1308.6729

Web End =INSPIRE ].

[29] ALICE collaboration, J/ production and nuclear e ects in p-Pb collisions at pSNN = 5.02 TeV, http://dx.doi.org/10.1007/JHEP02(2014)073

Web End =JHEP 02 (2014) 073 [http://arxiv.org/abs/1308.6726

Web End =arXiv:1308.6726 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1308.6726

Web End =INSPIRE ].

[30] F. Karsch and H. Satz, The spectral analysis of strongly interacting matter, http://dx.doi.org/10.1007/BF01475790

Web End =Z. Phys. C 51 http://dx.doi.org/10.1007/BF01475790

Web End =(1991) 209 [http://inspirehep.net/search?p=find+J+Z.Physik,C51,209

Web End =INSPIRE ].

[31] S. Digal, P. Petreczky and H. Satz, Quarkonium feed down and sequential suppression, http://dx.doi.org/10.1103/PhysRevD.64.094015

Web End =Phys. http://dx.doi.org/10.1103/PhysRevD.64.094015

Web End =Rev. D 64 (2001) 094015 [http://arxiv.org/abs/hep-ph/0106017

Web End =hep-ph/0106017 ] [http://inspirehep.net/search?p=find+EPRINT+hep-ph/0106017

Web End =INSPIRE ].

[32] CMS collaboration, Event activity dependence of (nS) production in psNN = 5.02 TeV

pPb and ps = 2.76 TeV pp collisions, http://dx.doi.org/10.1007/JHEP04(2014)103

Web End =JHEP 04 (2014) 103 [http://arxiv.org/abs/1312.6300

Web End =arXiv:1312.6300 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1312.6300

Web End =INSPIRE ].

[33] CMS collaboration, Observation of sequential suppression in PbPb collisions, http://dx.doi.org/10.1103/PhysRevLett.109.222301

Web End =Phys. Rev. http://dx.doi.org/10.1103/PhysRevLett.109.222301

Web End =Lett. 109 (2012) 222301 [http://arxiv.org/abs/1208.2826

Web End =arXiv:1208.2826 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1208.2826

Web End =INSPIRE ].

[34] LHCb collaboration, The LHCb detector at the LHC, http://dx.doi.org/10.1088/1748-0221/3/08/S08005

Web End =2008 JINST 3 S08005 [http://inspirehep.net/search?p=find+J+JINST,3,S08005

Web End =INSPIRE ].

[35] R. Arink et al., Performance of the LHCb outer tracker, http://dx.doi.org/10.1088/1748-0221/9/10/01002

Web End =2014 JINST 9 01002 [http://arxiv.org/abs/1311.3893

Web End =arXiv:1311.3893 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1311.3893

Web End =INSPIRE ].

[36] M. Adinol et al., Performance of the LHCb RICH detector at the LHC, http://dx.doi.org/10.1140/epjc/s10052-013-2431-9

Web End =Eur. Phys. J. C 73 http://dx.doi.org/10.1140/epjc/s10052-013-2431-9

Web End =(2013) 2431 [http://arxiv.org/abs/1211.6759

Web End =arXiv:1211.6759 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1211.6759

Web End =INSPIRE ].

[37] A.A. Alves Jr. et al., Performance of the LHCb muon system, http://dx.doi.org/10.1088/1748-0221/8/02/P02022

Web End =2013 JINST 8 P02022 [http://arxiv.org/abs/1211.1346

Web End =arXiv:1211.1346 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1211.1346

Web End =INSPIRE ].

[38] R. Aaij et al., The LHCb trigger and its performance in 2011, http://dx.doi.org/10.1088/1748-0221/8/04/P04022

Web End =2013 JINST 8 P04022 [http://arxiv.org/abs/1211.3055

Web End =arXiv:1211.3055 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1211.3055

Web End =INSPIRE ].

[39] T. Sjstrand, S. Mrenna and P.Z. Skands, PYTHIA 6.4 physics and manual, http://dx.doi.org/10.1088/1126-6708/2006/05/026

Web End =JHEP 05 http://dx.doi.org/10.1088/1126-6708/2006/05/026

Web End =(2006) 026 [http://arxiv.org/abs/hep-ph/0603175

Web End =hep-ph/0603175 ] [http://inspirehep.net/search?p=find+EPRINT+hep-ph/0603175

Web End =INSPIRE ].

[40] I. Belyaev et al., Handling of the generation of primary events in Gauss, the LHCb simulation framework, http://dx.doi.org/10.1109/NSSMIC.2010.5873949

Web End =IEEE Nucl. Sci. Symp. Conf. Rec. (NSS/MIC) (2010) 1155 .

[41] D.J. Lange, The EvtGen particle decay simulation package, http://dx.doi.org/10.1016/S0168-9002(01)00089-4

Web End =Nucl. Instrum. Meth. A 462 http://dx.doi.org/10.1016/S0168-9002(01)00089-4

Web End =(2001) 152 [http://inspirehep.net/search?p=find+J+Nucl.Instrum.Meth.,A462,152

Web End =INSPIRE ].

[42] P. Golonka and Z. Was, PHOTOS Monte Carlo: a precision tool for QED corrections in Z and W decays, http://dx.doi.org/10.1140/epjc/s2005-02396-4

Web End =Eur. Phys. J. C 45 (2006) 97 [http://arxiv.org/abs/hep-ph/0506026

Web End =hep-ph/0506026 ] [http://inspirehep.net/search?p=find+EPRINT+hep-ph/0506026

Web End =INSPIRE ].

[43] Geant4 collaboration, J. Allison et al., GEANT4 developments and applications, http://dx.doi.org/10.1109/TNS.2006.869826

Web End =IEEE http://dx.doi.org/10.1109/TNS.2006.869826

Web End =Trans. Nucl. Sci. 53 (2006) 270 .

[44] GEANT4 collaboration, S. Agostinelli et al., GEANT4: a simulation toolkit, http://dx.doi.org/10.1016/S0168-9002(03)01368-8

Web End =Nucl. Instrum. http://dx.doi.org/10.1016/S0168-9002(03)01368-8

Web End =Meth. A 506 (2003) 250 [http://inspirehep.net/search?p=find+J+Nucl.Instrum.Meth.,A506,250

Web End =INSPIRE ].

[45] M. Clemencic et al., The LHCb simulation application, Gauss: design, evolution and experience, http://dx.doi.org/10.1088/1742-6596/331/3/032023

Web End =J. Phys. Conf. Ser. 331 (2011) 032023 [http://inspirehep.net/search?p=find+J+J.Phys.Conf.Ser.,331,032023

Web End =INSPIRE ].

12

JHEP07(2014)094

[46] S. van der Meer, Calibration of the e ective beam height in the ISR, http://cdsweb.cern.ch/record/296752

Web End =CERN-ISR-PO-68-31 (1968).

[47] LHCb collaboration, Measurement of production in pp collisions at ps = 7 TeV, http://dx.doi.org/10.1140/epjc/s10052-012-2025-y

Web End =Eur. http://dx.doi.org/10.1140/epjc/s10052-012-2025-y

Web End =Phys. J. C 72 (2012) 2025 [http://arxiv.org/abs/1202.6579

Web End =arXiv:1202.6579 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1202.6579

Web End =INSPIRE ].

[48] LHCb collaboration, Production of J/ and mesons in pp collisions at ps = 8 TeV, http://dx.doi.org/10.1007/JHEP06(2013)064

Web End =JHEP http://dx.doi.org/10.1007/JHEP06(2013)064

Web End =06 (2013) 064 [http://arxiv.org/abs/1304.6977

Web End =arXiv:1304.6977 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1304.6977

Web End =INSPIRE ].

[49] LHCb collaboration, Measurement of production in pp collisions at ps = 2.76 TeV, http://dx.doi.org/10.1140/epjc/s10052-014-2835-1

Web End =Eur. http://dx.doi.org/10.1140/epjc/s10052-014-2835-1

Web End =Phys. J. C 74 (2014) 2835 [http://arxiv.org/abs/1402.2539

Web End =arXiv:1402.2539 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1402.2539

Web End =INSPIRE ].

[50] T. Skwarnicki, A study of the radiative cascade transitions between the [prime] and resonances, Ph.D. thesis, Institute of Nuclear Physics, Krakow, Poland (1986), http://inspirehep.net/record/230779/files/230779.pdf

Web End =DESY-F31-86-02 .

[51] Particle Data Group collaboration, J. Beringer et al., Review of particle physics, http://dx.doi.org/10.1103/PhysRevD.86.010001

Web End =Phys. http://dx.doi.org/10.1103/PhysRevD.86.010001

Web End =Rev. D 86 (2012) 010001 [http://inspirehep.net/search?p=find+J+Phys.Rev.,D86,010001

Web End =INSPIRE ].

[52] M. Pivk and F.R. Le Diberder, SPlot: a statistical tool to unfold data distributions, http://dx.doi.org/10.1016/j.nima.2005.08.106

Web End =Nucl. http://dx.doi.org/10.1016/j.nima.2005.08.106

Web End =Instrum. Meth. A 555 (2005) 356 [http://arxiv.org/abs/physics/0402083

Web End =physics/0402083 ] [http://inspirehep.net/search?p=find+EPRINT+physics/0402083

Web End =INSPIRE ].

[53] A. Jaeger et al., Measurement of the track nding e ciency, http://cds.cern.ch/record/1402577

Web End =CERN-LHCb-PUB-2011-025 (2011).

[54] F. Archilli et al., Performance of the muon identication at LHCb, http://dx.doi.org/10.1088/1748-0221/8/10/P10020

Web End =2013 JINST 8 P10020 [http://arxiv.org/abs/1306.0249

Web End =arXiv:1306.0249 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1306.0249

Web End =INSPIRE ].

[55] CMS collaboration, Measurement of the (1S), (2S) and (3S) polarizations in pp collisions at ps = 7 TeV, http://dx.doi.org/10.1103/PhysRevLett.110.081802

Web End =Phys. Rev. Lett. 110 (2013) 081802 [http://arxiv.org/abs/1209.2922

Web End =arXiv:1209.2922 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:1209.2922

Web End =INSPIRE ].

[56] ALICE and LHCb collaborations, Reference pp cross-sections for J/ studies in proton-lead collisions at psNN = 5.02 TeV and comparisons between ALICE and LHCb results,

https://cds.cern.ch/record/1639617

Web End =LHCb-CONF-2013-013 [https://cds.cern.ch/record/1639617

Web End =ALICE-PUBLIC-2013-002 ].

[57] K.J. Eskola, H. Paukkunen and C.A. Salgado, EPS09: a new generation of NLO and LO nuclear parton distribution functions, http://dx.doi.org/10.1088/1126-6708/2009/04/065

Web End =JHEP 04 (2009) 065 [http://arxiv.org/abs/0902.4154

Web End =arXiv:0902.4154 ] [http://inspirehep.net/search?p=find+EPRINT+arXiv:0902.4154

Web End =INSPIRE ].

13

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The LHCb collaboration

R. Aaij41, B. Adeva37, M. Adinol46, A. A older52, Z. Ajaltouni5, J. Albrecht9, F. Alessio38,M. Alexander51, S. Ali41, G. Alkhazov30, P. Alvarez Cartelle37, A.A. Alves Jr25,38, S. Amato2,S. Amerio22, Y. Amhis7, L. An3, L. Anderlini17,g, J. Anderson40, R. Andreassen57,M. Andreotti16,f, J.E. Andrews58, R.B. Appleby54, O. Aquines Gutierrez10, F. Archilli38,A. Artamonov35, M. Artuso59, E. Aslanides6, G. Auriemma25,n, M. Baalouch5, S. Bachmann11, J.J. Back48, A. Badalov36, V. Balagura31, W. Baldini16, R.J. Barlow54, C. Barschel38, S. Barsuk7,W. Barter47, V. Batozskaya28, A. Bay39, L. Beaucourt4, J. Beddow51, F. Bedeschi23, I. Bediaga1,S. Belogurov31, K. Belous35, I. Belyaev31, E. Ben-Haim8, G. Bencivenni18, S. Benson38,J. Benton46, A. Berezhnoy32, R. Bernet40, M.-O. Bettler47, M. van Beuzekom41, A. Bien11,S. Bifani45, T. Bird54, A. Bizzeti17,i, P.M. Bjrnstad54, T. Blake48, F. Blanc39, J. Blouw10,S. Blusk59, V. Bocci25, A. Bondar34, N. Bondar30,38, W. Bonivento15,38, S. Borghi54, A. Borgia59,M. Borsato7, T.J.V. Bowcock52, E. Bowen40, C. Bozzi16, T. Brambach9, J. van den Brand42,J. Bressieux39, D. Brett54, M. Britsch10, T. Britton59, J. Brodzicka54, N.H. Brook46, H. Brown52,A. Bursche40, G. Busetto22,q, J. Buytaert38, S. Cadeddu15, R. Calabrese16,f, M. Calvi20,k,M. Calvo Gomez36,o, A. Camboni36, P. Campana18,38, D. Campora Perez38, A. Carbone14,d,G. Carboni24,l, R. Cardinale19,38,j, A. Cardini15, H. Carranza-Mejia50, L. Carson50,K. Carvalho Akiba2, G. Casse52, L. Cassina20, L. Castillo Garcia38, M. Cattaneo38, Ch. Cauet9,R. Cenci58, M. Charles8, Ph. Charpentier38, S. Chen54, S.-F. Cheung55, N. Chiapolini40,M. Chrzaszcz40,26, K. Ciba38, X. Cid Vidal38, G. Ciezarek53, P.E.L. Clarke50, M. Clemencic38, H.V. Cli 47, J. Closier38, V. Coco38, J. Cogan6, E. Cogneras5, P. Collins38,A. Comerma-Montells11, A. Contu15,38, A. Cook46, M. Coombes46, S. Coquereau8, G. Corti38,M. Corvo16,f, I. Counts56, B. Couturier38, G.A. Cowan50, D.C. Craik48, M. Cruz Torres60,S. Cunli e53, R. Currie50, C. DAmbrosio38, J. Dalseno46, P. David8, P.N.Y. David41, A. Davis57,K. De Bruyn41, S. De Capua54, M. De Cian11, J.M. De Miranda1, L. De Paula2, W. De Silva57,P. De Simone18, D. Decamp4, M. Deckenho 9, L. Del Buono8, N. Dlage4, D. Derkach55,O. Deschamps5, F. Dettori42, A. Di Canto38, H. Dijkstra38, S. Donleavy52, F. Dordei11,M. Dorigo39, A. Dosil Surez37, D. Dossett48, A. Dovbnya43, G. Dujany54, F. Dupertuis39,P. Durante38, R. Dzhelyadin35, A. Dziurda26, A. Dzyuba30, S. Easo49,38, U. Egede53,V. Egorychev31, S. Eidelman34, S. Eisenhardt50, U. Eitschberger9, R. Ekelhof9, L. Eklund51,38,I. El Rifai5, Ch. Elsasser40, S. Ely59, S. Esen11, T. Evans55, A. Falabella16,f, C. Farber11,C. Farinelli41, N. Farley45, S. Farry52, D. Ferguson50, V. Fernandez Albor37,F. Ferreira Rodrigues1, M. Ferro-Luzzi38, S. Filippov33, M. Fiore16,f, M. Fiorini16,f, M. Firlej27,C. Fitzpatrick38, T. Fiutowski27, M. Fontana10, F. Fontanelli19,j, R. Forty38, O. Francisco2,M. Frank38, C. Frei38, M. Frosini17,38,g, J. Fu21,38, E. Furfaro24,l, A. Gallas Torreira37,D. Galli14,d, S. Gallorini22, S. Gambetta19,j, M. Gandelman2, P. Gandini59, Y. Gao3, J. Garofoli59,J. Garra Tico47, L. Garrido36, C. Gaspar38, R. Gauld55, L. Gavardi9, E. Gersabeck11,M. Gersabeck54, T. Gershon48, Ph. Ghez4, A. Gianelle22, S. Giani39, V. Gibson47, L. Giubega29,V.V. Gligorov38, C. Gbel60, D. Golubkov31, A. Golutvin53,31,38, A. Gomes1,a, H. Gordon38,C. Gotti20, M. Grabalosa Gndara5, R. Graciani Diaz36, L.A. Granado Cardoso38, E. Graugs36,G. Graziani17, A. Grecu29, E. Greening55, S. Gregson47, P. Gri th45, L. Grillo11, O. Grnberg62,B. Gui59, E. Gushchin33, Yu. Guz35,38, T. Gys38, C. Hadjivasiliou59, G. Haefeli39, C. Haen38, S.C. Haines47, S. Hall53, B. Hamilton58, T. Hampson46, X. Han11, S. Hansmann-Menzemer11,N. Harnew55, S.T. Harnew46, J. Harrison54, T. Hartmann62, J. He38, T. Head38, V. Heijne41,K. Hennessy52, P. Henrard5, L. Henry8, J.A. Hernando Morata37, E. van Herwijnen38, M. He62,A. Hicheur1, D. Hill55, M. Hoballah5, C. Hombach54, W. Hulsbergen41, P. Hunt55, N. Hussain55,D. Hutchcroft52, D. Hynds51, M. Idzik27, P. Ilten56, R. Jacobsson38, A. Jaeger11, J. Jalocha55,

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E. Jans41, P. Jaton39, A. Jawahery58, M. Jezabek26, F. Jing3, M. John55, D. Johnson55, C.R. Jones47, C. Joram38, B. Jost38, N. Jurik59, M. Kaballo9, S. Kandybei43, W. Kanso6,M. Karacson38, T.M. Karbach38, M. Kelsey59, I.R. Kenyon45, T. Ketel42, B. Khanji20,C. Khurewathanakul39, S. Klaver54, O. Kochebina7, M. Kolpin11, I. Komarov39, R.F. Koopman42,P. Koppenburg41,38, M. Korolev32, A. Kozlinskiy41, L. Kravchuk33, K. Kreplin11, M. Kreps48,G. Krocker11, P. Krokovny34, F. Kruse9, M. Kucharczyk20,26,38,k, V. Kudryavtsev34, K. Kurek28,T. Kvaratskheliya31, V.N. La Thi39, D. Lacarrere38, G. La erty54, A. Lai15, D. Lambert50, R.W. Lambert42, E. Lanciotti38, G. Lanfranchi18, C. Langenbruch38, B. Langhans38,T. Latham48, C. Lazzeroni45, R. Le Gac6, J. van Leerdam41, J.-P. Lees4, R. Lefvre5, A. Leat32,J. Lefranois7, S. Leo23, O. Leroy6, T. Lesiak26, B. Leverington11, Y. Li3, M. Liles52,R. Lindner38, C. Linn38, F. Lionetto40, B. Liu15, G. Liu38, S. Lohn38, I. Longsta 51, J.H. Lopes2,N. Lopez-March39, P. Lowdon40, H. Lu3, D. Lucchesi22,q, H. Luo50, A. Lupato22, E. Luppi16,f,O. Lupton55, F. Machefert7, I.V. Machikhiliyan31, F. Maciuc29, O. Maev30, S. Malde55,G. Manca15,e, G. Mancinelli6, M. Manzali16,f, J. Maratas5, J.F. Marchand4, U. Marconi14,C. Marin Benito36, P. Marino23,s, R. Marki39, J. Marks11, G. Martellotti25, A. Martens8,A. Martn Snchez7, M. Martinelli41, D. Martinez Santos42, F. Martinez Vidal64,D. Martins Tostes2, A. Massa erri1, R. Matev38, Z. Mathe38, C. Matteuzzi20, A. Mazurov16,f,M. McCann53, J. McCarthy45, A. McNab54, R. McNulty12, B. McSkelly52, B. Meadows57,55,F. Meier9, M. Meissner11, M. Merk41, D.A. Milanes8, M.-N. Minard4, N. Moggi14,J. Molina Rodriguez60, S. Monteil5, D. Moran54, M. Morandin22, P. Morawski26, A. Mord6, M.J. Morello23,s, J. Moron27, A.-B. Morris50, R. Mountain59, F. Muheim50, K. Mller40,R. Muresan29, M. Mussini14, B. Muster39, P. Naik46, T. Nakada39, R. Nandakumar49, I. Nasteva2,M. Needham50, N. Neri21, S. Neubert38, N. Neufeld38, M. Neuner11, A.D. Nguyen39,T.D. Nguyen39, C. Nguyen-Mau39,p, M. Nicol7, V. Niess5, R. Niet9, N. Nikitin32, T. Nikodem11,A. Novoselov35, A. Oblakowska-Mucha27, V. Obraztsov35, S. Oggero41, S. Ogilvy51,O. Okhrimenko44, R. Oldeman15,e, G. Onderwater65, M. Orlandea29, J.M. Otalora Goicochea2,P. Owen53, A. Oyanguren64, B.K. Pal59, A. Palano13,c, F. Palombo21,t, M. Palutan18,J. Panman38, A. Papanestis49,38, M. Pappagallo51, C. Parkes54, C.J. Parkinson9, G. Passaleva17, G.D. Patel52, M. Patel53, C. Patrignani19,j, A. Pazos Alvarez37, A. Pearce54, A. Pellegrino41,M. Pepe Altarelli38, S. Perazzini14,d, E. Perez Trigo37, P. Perret5, M. Perrin-Terrin6,L. Pescatore45, E. Pesen66, K. Petridis53, A. Petrolini19,j, E. Picatoste Olloqui36, B. Pietrzyk4,T. Pila48, D. Pinci25, A. Pistone19, S. Playfer50, M. Plo Casasus37, F. Polci8, A. Poluektov48,34,E. Polycarpo2, A. Popov35, D. Popov10, B. Popovici29, C. Potterat2, A. Powell55,J. Prisciandaro39, A. Pritchard52, C. Prouve46, V. Pugatch44, A. Puig Navarro39, G. Punzi23,r,W. Qian4, B. Rachwal26, J.H. Rademacker46, B. Rakotomiaramanana39, M. Rama18, M.S. Rangel2, I. Raniuk43, N. Rauschmayr38, G. Raven42, S. Reichert54, M.M. Reid48, A.C. dos Reis1, S. Ricciardi49, A. Richards53, M. Rihl38, K. Rinnert52, V. Rives Molina36, D.A. Roa Romero5, P. Robbe7, A.B. Rodrigues1, E. Rodrigues54, P. Rodriguez Perez54,S. Roiser38, V. Romanovsky35, A. Romero Vidal37, M. Rotondo22, J. Rouvinet39, T. Ruf38,F. Ru ni23, H. Ruiz36, P. Ruiz Valls64, G. Sabatino25,l, J.J. Saborido Silva37, N. Sagidova30,P. Sail51, B. Saitta15,e, V. Salustino Guimaraes2, C. Sanchez Mayordomo64, B. Sanmartin Sedes37,R. Santacesaria25, C. Santamarina Rios37, E. Santovetti24,l, M. Sapunov6, A. Sarti18,m,C. Satriano25,n, A. Satta24, M. Savrie16,f, D. Savrina31,32, M. Schiller42, H. Schindler38,M. Schlupp9, M. Schmelling10, B. Schmidt38, O. Schneider39, A. Schopper38, M.-H. Schune7,R. Schwemmer38, B. Sciascia18, A. Sciubba25, M. Seco37, A. Semennikov31, K. Senderowska27,I. Sepp53, N. Serra40, J. Serrano6, L. Sestini22, P. Seyfert11, M. Shapkin35, I. Shapoval16,43,f,Y. Shcheglov30, T. Shears52, L. Shekhtman34, V. Shevchenko63, A. Shires9, R. Silva Coutinho48,G. Simi22, M. Sirendi47, N. Skidmore46, T. Skwarnicki59, N.A. Smith52, E. Smith55,49, E. Smith53,

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J. Smith47, M. Smith54, H. Snoek41, M.D. Sokolo 57, F.J.P. Soler51, F. Soomro39, D. Souza46,B. Souza De Paula2, B. Spaan9, A. Sparkes50, F. Spinella23, P. Spradlin51, F. Stagni38, S. Stahl11,O. Steinkamp40, O. Stenyakin35, S. Stevenson55, S. Stoica29, S. Stone59, B. Storaci40,S. Stracka23,38, M. Straticiuc29, U. Straumann40, R. Stroili22, V.K. Subbiah38, L. Sun57,W. Sutcli e53, K. Swientek27, S. Swientek9, V. Syropoulos42, M. Szczekowski28, P. Szczypka39,38,D. Szilard2, T. Szumlak27, S. TJampens4, M. Teklishyn7, G. Tellarini16,f, F. Teubert38,C. Thomas55, E. Thomas38, J. van Tilburg41, V. Tisserand4, M. Tobin39, S. Tolk42,L. Tomassetti16,f, D. Tonelli38, S. Topp-Joergensen55, N. Torr55, E. Tourneer4, S. Tourneur39,

M.T. Tran39, M. Tresch40, A. Tsaregorodtsev6, P. Tsopelas41, N. Tuning41, M. Ubeda Garcia38,A. Ukleja28, A. Ustyuzhanin63, U. Uwer11, V. Vagnoni14, G. Valenti14, A. Vallier7,R. Vazquez Gomez18, P. Vazquez Regueiro37, C. Vzquez Sierra37, S. Vecchi16, J.J. Velthuis46,M. Veltri17,h, G. Veneziano39, M. Vesterinen11, B. Viaud7, D. Vieira2, M. Vieites Diaz37,X. Vilasis-Cardona36,o, A. Vollhardt40, D. Volyanskyy10, D. Voong46, A. Vorobyev30,V. Vorobyev34, C. Vo62, H. Voss10, J.A. de Vries41, R. Waldi62, C. Wallace48, R. Wallace12,J. Walsh23, S. Wandernoth11, J. Wang59, D.R. Ward47, N.K. Watson45, D. Websdale53,M. Whitehead48, J. Wicht38, D. Wiedner11, G. Wilkinson55, M.P. Williams45, M. Williams56, F.F. Wilson49, J. Wimberley58, J. Wishahi9, W. Wislicki28, M. Witek26, G. Wormser7,S.A. Wotton47, S. Wright47, S. Wu3, K. Wyllie38, Y. Xie61, Z. Xing59, Z. Xu39, Z. Yang3,X. Yuan3, O. Yushchenko35, M. Zangoli14, M. Zavertyaev10,b, F. Zhang3, L. Zhang59, W.C. Zhang12, Y. Zhang3, A. Zhelezov11, A. Zhokhov31, L. Zhong3, A. Zvyagin38

1 Centro Brasileiro de Pesquisas Fsicas (CBPF), Rio de Janeiro, Brazil

2 Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil

3 Center for High Energy Physics, Tsinghua University, Beijing, China

4 LAPP, Universit de Savoie, CNRS/IN2P3, Annecy-Le-Vieux, France

5 Clermont Universit, Universit Blaise Pascal, CNRS/IN2P3, LPC, Clermont-Ferrand, France

6 CPPM, Aix-Marseille Universit, CNRS/IN2P3, Marseille, France

7 LAL, Universit Paris-Sud, CNRS/IN2P3, Orsay, France

8 LPNHE, Universit Pierre et Marie Curie, Universit Paris Diderot, CNRS/IN2P3, Paris, France

9 Fakultat Physik, Technische Universitat Dortmund, Dortmund, Germany

10 Max-Planck-Institut fr Kernphysik (MPIK), Heidelberg, Germany

11 Physikalisches Institut, Ruprecht-Karls-Universitat Heidelberg, Heidelberg, Germany

12 School of Physics, University College Dublin, Dublin, Ireland

13 Sezione INFN di Bari, Bari, Italy

14 Sezione INFN di Bologna, Bologna, Italy

15 Sezione INFN di Cagliari, Cagliari, Italy

16 Sezione INFN di Ferrara, Ferrara, Italy

17 Sezione INFN di Firenze, Firenze, Italy

18 Laboratori Nazionali dellINFN di Frascati, Frascati, Italy

19 Sezione INFN di Genova, Genova, Italy

20 Sezione INFN di Milano Bicocca, Milano, Italy

21 Sezione INFN di Milano, Milano, Italy

22 Sezione INFN di Padova, Padova, Italy

23 Sezione INFN di Pisa, Pisa, Italy

24 Sezione INFN di Roma Tor Vergata, Roma, Italy

25 Sezione INFN di Roma La Sapienza, Roma, Italy

26 Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences, Krakw, Poland

27 AGH - University of Science and Technology, Faculty of Physics and Applied Computer Science, Krakw, Poland

28 National Center for Nuclear Research (NCBJ), Warsaw, Poland

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29 Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele, Romania

30 Petersburg Nuclear Physics Institute (PNPI), Gatchina, Russia

31 Institute of Theoretical and Experimental Physics (ITEP), Moscow, Russia

32 Institute of Nuclear Physics, Moscow State University (SINP MSU), Moscow, Russia

33 Institute for Nuclear Research of the Russian Academy of Sciences (INR RAN), Moscow, Russia

34 Budker Institute of Nuclear Physics (SB RAS) and Novosibirsk State University, Novosibirsk, Russia

35 Institute for High Energy Physics (IHEP), Protvino, Russia

36 Universitat de Barcelona, Barcelona, Spain

37 Universidad de Santiago de Compostela, Santiago de Compostela, Spain

38 European Organization for Nuclear Research (CERN), Geneva, Switzerland

39 Ecole Polytechnique Fdrale de Lausanne (EPFL), Lausanne, Switzerland

40 Physik-Institut, Universitat Zrich, Zrich, Switzerland

41 Nikhef National Institute for Subatomic Physics, Amsterdam, The Netherlands

42 Nikhef National Institute for Subatomic Physics and VU University Amsterdam, Amsterdam, The Netherlands

43 NSC Kharkiv Institute of Physics and Technology (NSC KIPT), Kharkiv, Ukraine

44 Institute for Nuclear Research of the National Academy of Sciences (KINR), Kyiv, Ukraine

45 University of Birmingham, Birmingham, United Kingdom

46 H.H. Wills Physics Laboratory, University of Bristol, Bristol, United Kingdom

47 Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom

48 Department of Physics, University of Warwick, Coventry, United Kingdom

49 STFC Rutherford Appleton Laboratory, Didcot, United Kingdom

50 School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom

51 School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom

52 Oliver Lodge Laboratory, University of Liverpool, Liverpool, United Kingdom

53 Imperial College London, London, United Kingdom

54 School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom

55 Department of Physics, University of Oxford, Oxford, United Kingdom

56 Massachusetts Institute of Technology, Cambridge, MA, United States

57 University of Cincinnati, Cincinnati, OH, United States

58 University of Maryland, College Park, MD, United States

59 Syracuse University, Syracuse, NY, United States

60 Pontifcia Universidade Catlica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, Brazil, associated to2

61 Institute of Particle Physics, Central China Normal University, Wuhan, Hubei, China, associated to3

62 Institut fr Physik, Universitat Rostock, Rostock, Germany, associated to11

63 National Research Centre Kurchatov Institute, Moscow, Russia, associated to31

64 Instituto de Fisica Corpuscular (IFIC), Universitat de Valencia-CSIC, Valencia, Spain, associated to36

65 KVI - University of Groningen, Groningen, The Netherlands, associated to41

66 Celal Bayar University, Manisa, Turkey, associated to38

a Universidade Federal do Tringulo Mineiro (UFTM), Uberaba-MG, Brazil

b P.N. Lebedev Physical Institute, Russian Academy of Science (LPI RAS), Moscow, Russia

c Universit di Bari, Bari, Italy

d Universit di Bologna, Bologna, Italy

e Universit di Cagliari, Cagliari, Italy

f Universit di Ferrara, Ferrara, Italy

g Universit di Firenze, Firenze, Italy

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h Universit di Urbino, Urbino, Italy

i Universit di Modena e Reggio Emilia, Modena, Italy

j Universit di Genova, Genova, Italy

k Universit di Milano Bicocca, Milano, Italy

l Universit di Roma Tor Vergata, Roma, Italy

m Universit di Roma La Sapienza, Roma, Italy

n Universit della Basilicata, Potenza, Italy

o LIFAELS, La Salle, Universitat Ramon Llull, Barcelona, Spain

p Hanoi University of Science, Hanoi, Viet Nam

q Universit di Padova, Padova, Italy

r Universit di Pisa, Pisa, Italy

s Scuola Normale Superiore, Pisa, Italy

t Universit degli Studi di Milano, Milano, Italy

JHEP07(2014)094

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