Measurement of the kT Distribution of Particles in Jets Produced in ppbar Collisions at s**(1/2)=1.96$-TeV

TL;DR

This paper measures the transverse momentum distribution of particles within jets in proton-antiproton collisions at 1.96 TeV, comparing results to QCD predictions to understand jet fragmentation.

Contribution

It provides the first detailed measurement of the $k_{T}$ distribution in jets at this energy, validating perturbative QCD models of jet fragmentation.

Findings

Data agrees with resummed perturbative QCD predictions

Perturbative stage dominates jet fragmentation characteristics

Results support the validity of theoretical models in describing jet structure

Abstract

We present a measurement of the transverse momentum with respect to the jet axis ($k_{T}$) of particles in jets produced in $p\bar p$ collisions at $\sqrt{s}=1.96$ TeV. Results are obtained for charged particles within a cone of opening angle 0.5 radians around the jet axis in events with dijet invariant masses between 66 and 737 GeV/c$^{2}$. The experimental data are compared to theoretical predictions obtained for fragmentation partons within the framework of resummed perturbative QCD using the modified leading log and next-to-modified leading log approximations. The comparison shows that trends in data are successfully described by the theoretical predictions, indicating that the perturbative QCD stage of jet fragmentation is dominant in shaping basic jet characteristics.