Radiative energy loss and radiative p_T-broadening of high-energy partons in QCD matter

TL;DR

This paper investigates the relationship between radiative energy loss and transverse momentum broadening of high-energy partons in QCD matter, using the BDMPS-Z formalism to derive new double logarithmic corrections and resummations.

Contribution

It introduces a double logarithmic correction to parton energy loss and connects radiative energy loss with transverse momentum broadening through resummation techniques.

Findings

Double logarithmic correction proportional to ln^2(L/l_0) to energy loss.

Resummation of double logarithmic terms yields a relation between energy loss and p_T-broadening.

Results agree with renormalization of qhat in previous studies.

Abstract

We study the connection between radiative energy loss and radiative p_T-broadening of a high-energy quark or gluon passing through QCD matter. The generalized Baier-Dokshitzer-Mueller-Peigne-Schiff-Zakharov (BDMPS-Z) formalism is used to calculate energy loss due to multiple gluon emission. With L the length of the matter and l_0 the size of constituents of the matter we find a double logarithmic correction proportional to ln^2(L/l_0) to parton energy loss due to two-gluon emission. We also show that the radiative energy loss per unit length -dE/dz = alpha_s N_c < p_T^2 >/12 by carrying out a resummation of the double logarithmic terms. Here, the transverse momentum broadening <p_T^2> is obtained by resumming terms proportional to alpha_s ln^2(L/l_0) in Ref. [11]. Our result agrees with that by the renormalization of qhat proposed in Refs. [13,14].