Bjorken variable and scale dependence of quark transport coefficient in semi-inclusive lepton-production of hadron off nuclei

TL;DR

This paper investigates how the quark transport coefficient varies with the Bjorken variable and scale in deep inelastic lepton-nucleus scattering, using models compared to HERMES data to understand parton propagation in cold nuclear matter.

Contribution

It introduces a relation between the quark transport coefficient and measurable kinematic variables, proposing four models and identifying the scale dependence consistent with experimental data.

Findings

The quark transport coefficient depends on Bjorken variable x and scale Q^2.

Constant, power-law, and double power-law models are inconsistent with data.

The scale dependence of the quark transport coefficient aligns partially with HERMES measurements.

Abstract

Nuclear modification of hadron production in deep inelastic lepton-nucleus scattering can be applied to study the parton propagation mechanism in cold nuclear matter. By means of the analytic parameterization of quenching weight based on BDMPS formalism with the target nuclear geometry effect, the leading-order computations for hadron multiplicity ratios are performed with comparison to the HERMES charged pions production data on the quarks hadronization occurring outside the nucleus. The relation is discovered between quark transport coefficient and the measurable kinematic variables in deep inelastic scattering. Four models are proposed on the quark transport coefficient. The constant model, the power-law model and the double power-law model can be ruled out because of the experimental fact that the transverse momentum broadening increases as a function of the photon virtuality $Q^2$. The quark transport coefficient is determined as a function of the Bjorken variable $x$ and scale $Q^2$. The trend of quark transport coefficient in respect of Bjorken variable $x$ and scale $Q^2$ is qualitatively in partial agreement with HERMES experimental data on transverse momentum broadening. It is hoped that our effort is conducive to understanding of jet quenching phenomenon in relativistic heavy ion collisions.