Measurement of the nuclear modification factor for high-pT charged hadrons in p+Pb collisions with the ATLAS detector

The charged hadron spectra in p+Pb and pp collisions at sNN=s=5.02 TeV are measured with the ATLAS experiment at the LHC. The measurements are performed with p+Pb data recorded in 2013 with an integrated luminosity of 25 nb−1 and pp data recorded in 2015 with an integrated luminosity of 28 pb−1. The p+Pb results are compared to pp spectra, presented as a ratio of transverse momentum distributions in the two systems scaled by the number of binary nucleon-nucleon collisions, the nuclear modification factor RpPb. The study of RpPb allows a detailed comparison of the collision systems in different centrality intervals and in a wide range of transverse momentum. It is shown that the nuclear modification factor does not have any significant deviation from unity in the high transverse momentum region.