论文标题
通过面对电流NLO Parton碎片功能从强子抑制中提取喷气运输系数
Extracting the jet transport coefficient from hadron suppressions by confronting current NLO parton fragmentation functions
论文作者
论文摘要
在高能重型离子碰撞中，单个横向动量（$ p _ {\ rm t} $）的核修饰因子在近代到领先阶（NLO）扰动QCD Parton模型中研究了高能重型离子碰撞。 $ A+A $碰撞中的Parton碎片函数（FFS）由于喷气能量损失而被修改，该损失与喷气运输系数$ \ hat {q} $成正比，表征了Parton喷气机与生产介质之间的相互作用。通过面对大型$ p _ {\ rm t} $ HADRON PRODUCTIONS的6套Nlo Parton FFS，我们通过全球拟合单个强子和Dihadron抑制的数据来提取$ \ hat {q} $ $ \ sqrt {s _ {\ rm nn}} = 200 $ gev和$ \ hat {q}/t^3 = 3.07-3.98 $ at $ t = 480 $ t = 480 $ meV in Central $ pb+pb $ collisions $ \ sqrt {数值结果表明，$ \ hat {q} $提取的不确定性是由Gluon-to-Hadron在6组FFS中的不同贡献所带来的，因为Gluon Energy损失是$ 9/4 $ $ $ $ $ $ $ $ $ $ $ $乘以夸克能量损失。
Nuclear modification factors of single hadrons and dihadrons at large transverse momentum ($p_{\rm T}$) in high-energy heavy-ion 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 $\hat{q}$ characterizing the interaction between the parton jet and the produced medium. By confronting 6 current sets of NLO parton FFs for large $p_{\rm T}$ hadron productions, we extract $\hat{q}$ quantitatively via a global fit to data for both single hadron and dihadron suppressions, and obtain $\hat{q}/T^3 = 4.74 - 6.72$ at $T = 370$ MeV in central $Au+Au$ collisions at $\sqrt{s_{\rm NN}}=200$ GeV, and $\hat{q}/T^3 = 3.07 - 3.98$ at $T = 480$ MeV in central $Pb+Pb$ collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV. The numerical results show that the uncertainties for $\hat{q}$ extraction are brought by the different contributions of gluon-to-hadron in the 6 sets of FFs due to gluon energy loss being $9/4$ times of quark energy loss.
