Nonperturbative effects on radiative energy loss of heavy quarks
Abstract
The radiative energy loss of fast partons traveling through the quarkgluon plasma (QGP) is commonly studied within perturbative QCD (pQCD). Nonperturbative (NP) effects, which are expected to become important near the critical temperature, have been much less investigated. Here, we utilize a recently developed T matrix approach to incorporate NP effects for gluon emission off heavy quarks propagating through the QGP. We set up four cases that contain, starting from a Born diagram calculation with color Coulomb interaction, an increasing level of NP components, by subsequently including (remnants of ) confining interactions, resummation in the heavylight scattering amplitude, and offshell spectral functions for both heavy and light partons. For each case we compute the power spectra of the emitted gluons, heavyquark transport coefficients (drag and transversemomentum broadening, q ̂), and the pathlength dependent energy loss within a "QGP brick" at fixed temperature. Investigating the differences in these quantities between the four cases illustrates how NP mechanisms affect gluon radiation processes. While the baseline perturbative processes experience a strong suppression of soft radiation due to thermal masses of the emitted gluons, confining interactions, ladder resummations and broad spectral functions (re)generate a large enhancement toward low momenta and low temperatures. For example, for a 10 GeV charm quark at 200 MeV temperature, they enhance the transport coefficients by up to a factor of 10, while the results smoothly converge to perturbative results at sufficiently hard scales.
 Publication:

Journal of High Energy Physics
 Pub Date:
 August 2020
 DOI:
 10.1007/JHEP08(2020)168
 arXiv:
 arXiv:2003.12536
 Bibcode:
 2020JHEP...08..168L
 Keywords:

 Heavy Ion Phenomenology;
 Jets;
 Nuclear Theory;
 High Energy Physics  Phenomenology;
 Nuclear Experiment
 EPrint:
 24 pages, 13 figures