Measurement of dijet $k_{\rm T}$ in p-Pb collisions at ${\sqrt{s_{\rm NN}}=5.02}$ TeV

TL;DR

This study measures dijet correlations in p-Pb collisions at 5.02 TeV to investigate nuclear matter effects, finding no significant modifications in dijet acoplanarity compared to proton-proton collisions or models.

Contribution

First measurement of dijet $k_T$ in p-Pb collisions at 5.02 TeV using ALICE, providing insights into nuclear matter effects on dijet acoplanarity.

Findings

No significant modification of $k_T$ observed in p-Pb vs pp collisions.

Dijet acoplanarity consistent with PYTHIA8 predictions.

Results suggest minimal nuclear matter effects on dijet transverse momentum balance.

Abstract

A measurement of dijet correlations in p-Pb collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV with the ALICE detector is presented. Jets are reconstructed from charged particles measured in the central tracking detectors and neutral energy deposited in the electromagnetic calorimeter. The transverse momentum of the full jet (clustered from charged and neutral constituents) and charged jet (clustered from charged particles only) is corrected event-by-event for the contribution of the underlying event, while corrections for underlying event fluctuations and finite detector resolution are applied on an inclusive basis. A projection of the dijet transverse momentum, $k_{\rm Ty} = p_\rm{T,jet}^\rm{ch+ne} \; \rm{sin}(\Delta\varphi_{\rm{dijet}})$ with $\Delta\varphi_{\rm{dijet}}$ the azimuthal angle between a full and charged jet and $p_\rm{T,jet}^\rm{ch+ne}$ the transverse momentum of the full jet, is used to study nuclear matter effects in p-Pb collisions. This observable is sensitive to the acoplanarity of dijet production and its potential modification in p-Pb collisions with respect to pp collisions. Measurements of the dijet $k_{\rm Ty}$ as a function of the transverse momentum of the full and recoil charged jet, and the event multiplicity are presented. No significant modification of $k_{\rm Ty}$ due to nuclear matter effects in p-Pb collisions with respect to the event multiplicity or a PYTHIA8 reference is observed.