Abstract

Bose-Einstein correlations between identified charged pions are measured for p+Pb collisions at √SNN = 5.02 TeV with the ATLAS detector using a total integrated luminosity of 28 nb−1. Pions are identified using ionisation energy loss measured in the pixel detector. Two-particle correlation functions and the extracted source radii are presented as a function of average transverse pair momentum (kT) and rapidity (yππ*) as well as collision centrality. Pairs are selected with a rapidity −2 < yππ* < 1 and with an average transverse momentum 0.1 < kT < 0.8 GeV. The effect on the two-particle correlation function from jet fragmentation is studied, and a new method for constraining its contributions to the measured correlations is described. The measured source sizes are substantially larger in more central collisions and are observed to decrease with increasing pair kT. A correlation with the local single-particle multiplicity dNch/dy* is demonstrated. The scaling of the extracted radii with the mean number of participants is also used to compare a selection of initial-geometry models. The cross term Ro1, which couples radial and longitudinal expansion, is measured as a function of rapidity, and a departure from zero is observed with 4.8 σ combined significance for yππ* > −1 in the most central events.

Details

Title
Femtoscopy in √SNN = 5.02 TeV p-Pb collisions with ATLAS
Author
Clark, Michael
Section
Multi-particle correlations and fluctuations: from small to large systems
Publication year
2017
Publication date
2017
Publisher
EDP Sciences
ISSN
21016275
e-ISSN
2100014X
Source type
Conference Paper
Language of publication
English
ProQuest document ID
2057752978
Copyright
© 2017. This work is licensed under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and conditions, you may use this content in accordance with the terms of the License.