Production of leading charged particles and leading charged-particle jets at small transverse momenta in pp collisions at sqrt(s) = 8 TeV

TL;DR

This paper investigates the production rates of leading charged particles and jets at low transverse momenta in proton-proton collisions at 8 TeV, providing insights into QCD processes and parton saturation effects.

Contribution

It presents the first detailed measurement of leading charged particles and jets at small transverse momenta in pp collisions at 8 TeV, probing the transition between soft and hard QCD regimes.

Findings

Data sensitive to parton density saturation scale

Results inform models of multiple partonic interactions

Measurements constrain soft-hard transition in QCD

Abstract

The per-event yield of the highest transverse momentum charged particle and charged-particle jet, integrated above a given pt(min) threshold starting at pt(min) = 0.8 and 1 GeV, respectively, is studied in pp collisions at sqrt(s) = 8 TeV. The particles and the jets are measured in the pseudorapidity ranges abs(eta) < 2.4 and 1.9, respectively. The data are sensitive to the momentum scale at which parton densities saturate in the proton, to multiple partonic interactions, and to other key aspects of the transition between the soft and hard QCD regimes in hadronic collisions.