Jet transport coefficient $\hat{q}$ in lattice QCD

• DOI: 10.48550/arxiv.2010.14463
• Publication Date: 2020-01-01
• Authors: Kumar, Amit; Majumder, Abhijit; Weber, Johannes H...
• Keywords: Nuclear Theory (nucl-th); High Energy Physics - Phenomenology; High Energy Physics - Lattice; High Energy Physics - Phenomenology (hep-ph); Nuclear Theory; High Energy Physics - Lattice (hep-lat); FOS: Physical sciences; Nuclear Experiment (nucl-ex); Nuclear Experiment

We present the first calculation of the jet transport coefficient $\hat{q}$ in quenched and (2+1)-flavor QCD on a 4-D Euclidean lattice. The light-like propagation of an energetic parton is factorized from the mean square gain in momentum transverse to the direction of propagation, which is expressed in terms of the thermal field-strength field-strength correlator. The leading-twist term in its operator product expansion is calculated on the lattice. Continuum extrapolated quenched results, and full QCD estimates based on un-renormalized lattice data, over multiple lattice sizes, are compared with (non) perturbative calculations and phenomenological extractions of $\hat{q}$. The lattice data for $\hat{q}$ show a temperature dependence similar to the entropy density. Within uncertainties, these are consistent with phenomenological extractions, contrary to calculations using perturbation theory.<br/>Published version. 13 pages+6 figures. Revtex4.1<br/>