Higher-twist contributions to the transverse momentum broadening in semi-inclusive deep inelastic scattering off large nuclei

TL;DR

This paper investigates higher-twist effects on transverse momentum broadening in semi-inclusive deep inelastic scattering off large nuclei, emphasizing the importance of twist-four and twist-six contributions for precise jet transport parameter extraction.

Contribution

It calculates twist-six power corrections to transverse momentum broadening, revealing their dependence on nuclear modifications and their significance at intermediate Q^2 scales.

Findings

Twist-six contributions lack additional nuclear enhancement.

Power corrections depend on nuclear modifications of parton distributions.

Higher-twist effects are crucial for accurate jet transport parameter extraction.

Abstract

Multiple scattering leads to transverse momentum broadening of the struck quark in semi-inclusive deeply inelastic scatterings (SIDIS). Nuclear broadening of the transverse momentum squared at the leading twist is determined by the twist-four collinear quark-gluon correlation function of the target nucleus that is in turn related to the jet transport parameter inside the nuclear medium. The twist-six contributions to the transverse momentum broadening are calculated as power corrections $\sim 1/Q^2$. Such power corrections are found to have no extra nuclear enhancement beyond the twist-four matrix elements and are determined by the nuclear modification of collinear parton distribution and correlation functions. They become important for an accurate extraction of the jet transport parameter inside large nuclei and its scale evolution at intermediate values of the hard scale $Q^2$.