2020/09/11 by Amit Kumar, Kumar, Amit, Abhijit Majumder +3
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High-Energy Particle Collisions Research #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2009.05655
openalex publication_date 2020/09/11 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
The transport coefficient \q is a leading coefficient that controls\nthe modification of the hard parton traversing QGP, and hence, responsible for\nthe suppression of the high transverse momentum (transverse to the beam\ndirection) charged-hadrons in heavy-ion collisions. In this article, we present\nthe first unquenched lattice QCD calculation of \q. The calculation is\ncarried out using (2+1)-flavor of quarks, using the highly improved staggered\nquark action (HISQ) and tree-level Symanzik improved gauge action. The\ncalculation is performed in a wide range of temperatures, ranging from 200 MeV\n<T< 800 MeV using MILC code package. We considered a leading-order process\nwhere a hard parton scatters off the glue field of a thermal QCD medium by\nexchanging a Glauber gluon (whose transverse momentum is larger than its\nlongitudinal components). The hard scale associated with the jet parton allows\nthe coupling of the gluon to that parton to be treated in perturbation theory.\nThe coupling of the gluon to the medium is treated non-perturbatively. This\nnon-perturbative part is expressed in terms of a non-local (two-point)\nfield-strength-field-strength operator product which can be Taylor expanded\nafter analytic continuation to the deep Euclidean region. Such an expansion\nallows us to write \q in terms of a series of local operators, which are\nsuppressed by factors of the hard parton energy. The calculated \q and\nits temperature dependence demonstrates reasonable agreement with the\nphenomenological extraction carried out by the JET collaboration.\n