TY - JOUR

T1 - Femtoscopy with identified charged pions in proton-lead collisions at √sNN=5.02 TeV with ATLAS

AU - Barton, Adam Edward

AU - Beattie, Michael

AU - Bertram, Iain Alexander

AU - Borissov, Guennadi

AU - Bouhova-Thacker, Evelina Vassileva

AU - Dearnaley, William

AU - Fox, Harald

AU - Henderson, Robert Charles William

AU - Jones, Roger William Lewis

AU - Kartvelishvili, Vakhtang

AU - Long, Robin Eamonn

AU - Love, Peter Allan

AU - Muenstermann, Daniel Matthias Alfred

AU - Parker, Adam Jackson

AU - Skinner, Malcolm

AU - Smizanska, Maria

AU - Walder, James William

AU - Wharton, Andy

AU - The ATLAS collaboration

N1 - Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3

PY - 2017/12/28

Y1 - 2017/12/28

N2 - Bose-Einstein correlations between identified charged pions are measured for p+Pb collisions at √sNN=5.02 TeV using data recorded by the ATLAS detector at the CERN Large Hadron Collider corresponding to a total integrated luminosity of 28nb−1. Pions are identified using ionization energy loss measured in the pixel detector. Two-particle correlation functions and the extracted source radii are presented as a function of collision centrality as well as the average transverse momentum (kT) and rapidity (y★ππ) of the pair. Pairs are selected with a rapidity −2<y★ππ<1 and with an average transverse momentum 0.1<kT<0.8GeV. The effect of jet fragmentation on the two-particle correlation function is studied, and a method using opposite-charge pair data to constrain 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 of the radii with the local charged-particle density is demonstrated. The scaling of the extracted radii with the mean number of participating nucleons is also used to compare a selection of initial-geometry models. The cross term Rol is measured as a function of rapidity, and a nonzero value is observed with 5.1σ combined significance for −1<y★ππ<1 in the most central events.

AB - Bose-Einstein correlations between identified charged pions are measured for p+Pb collisions at √sNN=5.02 TeV using data recorded by the ATLAS detector at the CERN Large Hadron Collider corresponding to a total integrated luminosity of 28nb−1. Pions are identified using ionization energy loss measured in the pixel detector. Two-particle correlation functions and the extracted source radii are presented as a function of collision centrality as well as the average transverse momentum (kT) and rapidity (y★ππ) of the pair. Pairs are selected with a rapidity −2<y★ππ<1 and with an average transverse momentum 0.1<kT<0.8GeV. The effect of jet fragmentation on the two-particle correlation function is studied, and a method using opposite-charge pair data to constrain 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 of the radii with the local charged-particle density is demonstrated. The scaling of the extracted radii with the mean number of participating nucleons is also used to compare a selection of initial-geometry models. The cross term Rol is measured as a function of rapidity, and a nonzero value is observed with 5.1σ combined significance for −1<y★ππ<1 in the most central events.

U2 - 10.1103/PhysRevC.96.064908

DO - 10.1103/PhysRevC.96.064908

M3 - Journal article

VL - 96

JO - Physical Review C

JF - Physical Review C

SN - 0556-2813

IS - 6

M1 - 064908

ER -