Measurement of the Centrality Dependence of the Dijet Yield in p+Pb Collisions at sNN=8.16 TeV with the ATLAS Detector

UNSPECIFIED (2024) Measurement of the Centrality Dependence of the Dijet Yield in p+Pb Collisions at sNN=8.16 TeV with the ATLAS Detector. Physical review letters, 132 (10): 102301. ISSN 0031-9007

Abstract

ATLAS measured the centrality dependence of the dijet yield using 165     nb − 1 of p + Pb data collected at √ s NN = 8.16     TeV in 2016. The event centrality, which reflects the p + Pb impact parameter, is characterized by the total transverse energy registered in the Pb-going side of the forward calorimeter. The central-to-peripheral ratio of the scaled dijet yields, R CP , is evaluated, and the results are presented as a function of variables that reflect the kinematics of the initial hard parton scattering process. The R CP shows a scaling with the Bjorken x of the parton originating from the proton, x p , while no such trend is observed as a function of x Pb . This analysis provides unique input to understanding the role of small proton spatial configurations in p + Pb collisions by covering parton momentum fractions from the valence region down to x p ∼ 10 − 3 and x Pb ∼ 4 × 10 − 4 .