Extracting the jet transport coefficient from hadron suppressions by confronting current NLO parton fragmentation functions

作者：Han, Qing-Fei; Xie, Man; Zhang, Han-Zhong^*

来源：EUROPEAN PHYSICAL JOURNAL PLUS, 2022, 137(9): 1056.

DOI：10.1140/epjp/s13360-022-03247-9

• PB-PB COLLISIONS
• TRANSVERSE-MOMENTUM
• ENERGY-LOSS
• SPECTRA
• PHOTON
• ORDER
• MODEL
• FLOW

Nuclear modification factors of single hadrons and dihadrons at large transverse momentum (P-T) in high-energy heavyion collisions are studied in a next-to-leading-order (NLO) perturbative QCD parton model. Parton fragmentation functions (FFs) in A +A collisions are modified due to jet energy loss which is proportional to the jet transport coefficient (q) over cap characterizing the interaction between the parton jet and the produced medium. By confronting 6 current sets of NLO parton FFs for large p(T) hadron productions, we extract (q) over cap quantitatively via a global fit to data for both single hadron and dihadron suppressions and obtain (q) over cap /T-3 = 4.74 - 6.72 at T = 370 MeV in central Au + Au collisions at root sNN = 200 GeV, and (q) over cap /T-3 = 3.07 - 3.98 at T = 480 MeV in central Pb + Pb collisions at root sNN = 2.76 TeV. The numerical results show that the uncertainties for q extraction are brought by the different contributions of gluon-to-hadron in the six sets of FFs due to gluon energy loss being 9/4 times of quark energy loss.