Azimuthal jet flavor tomography with CUJET2.0 of nuclear collisions at RHIC and LHC

作者：Xu Jiechen; Buzzatti Alessandro; Gyulassy Miklos^*

来源：The Journal of High Energy Physics, 2014, 2014(8): 063.

DOI：10.1007/JHEP08(2014)063

• Jets
• Heavy Ion Phenomenology

A perturbative QCD based jet tomographic Monte Carlo model, CUJET2.0, is presented to predict jet quenching observables in relativistic heavy ion collisions at RHIC/BNL and LHC/CERN energies. This model generalizes the DGLV theory of flavor dependent radiative energy loss by including multi-scale running strong coupling effects. It generalizes CUJET1.0 by computing jet path integrations though more realistic 2 + 1D transverse and longitudinally expanding viscous hydrodynamical fields contrained by fits to low p(T) flow data. The CUJET2.0 output depends on three control parameters, (alpha(max), f(E), f(M)), corresponding to an assumed upper bound on the vacuum running coupling in the infrared and two chromo-electric and magnetic QGP screening mass scales (f(E)mu(T), f(M mu)mu(T)) where mu(T) is the 1-loop Debye mass. We compare numerical results as a function of alpha(max) for pure and deformed HTL dynamically enhanced scattering cases corresponding to (f(E) = 1, 2, f(M) = 0) to data of the nuclear modification factor, R-AA(f) (p(T), phi; root s, b) for jet fragment flavors f = pi, D, B, e at root s = 0.2 - 2.76 ATeV c. m. energies per nucleon pair and with impact parameter b = 2.4, 7.5 fm. A chi(2) analysis is presented and shows that R-AA(pi) data from RHIC and LHC are consistent with CUJET2.0 at the chi(2)/d.o.f < 2 level for alpha(max) = 0.23-0.30. The corresponding <(q)over cap>(E-jet, T)/T-3 effective jet transport coefficient field of this model is computed to facilitate comparison to other jet tomographic models in the literature. The predicted elliptic asymmetry, v(2) (p(T); root s, b) is, however, found to significantly underestimated relative to RHIC and LHC data. We find the chi(2)(v2) analysis shows that v(2) is very sensitive to allowing even as little as 10% variations of the path averaged alpha(max) along in and out of reaction plane paths.

• 出版日期2014-8-11