Inclusive hadronic distributions in jets and sub-jets with jet axis from color current

TL;DR

This paper calculates the hadronic transverse momentum spectrum and gluon to quark multiplicity ratio inside high-energy sub-jets, incorporating precise jet axis definitions and corrections, with results aligning well with experimental data.

Contribution

It introduces a refined calculation of hadronic distributions in jets using a precise jet axis definition and includes corrections beyond the standard approximation.

Findings

$ ext{kt}$-spectrum matches CDF data after normalization

Gluon to quark multiplicity ratio $r$ predicted but not yet measured

Corrections of order $ ext{O}( oot ext{ extstyle}( ext{ extstyle}\alpha_s)$ included

Abstract

The hadronic $\kt$-spectrum and the gluon to quark average multiplicity ratio $r=N_g/N_q$ inside a high energy sub-jet are determined from a precise definition of the jet axis, including corrections of relative magnitude ${\cal O}(\sqrt{\alpha_s})$ with respect to the Modified Leading Logarithmic Approximation (MLLA), in the limiting spectrum approximation (assuming an infrared cut-off $Q_0 =\lqcd$). The results for the $\kt$-spectrum in the limiting spectrum approximation are found to be, after normalization, in impressive agreement with measurements by the CDF collaboration and the ratio has not been measured yet.