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arXiv 1408.3906nucl-ex
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PHENIX实验中$p$ + $p$、$d$ +Au和Cu+Cu碰撞的重味衰变电子测量

Measurement of electrons from heavy-flavor decays from $p$+$p$, $d$+Au, and Cu+Cu collisions in the PHENIX experiment

Sanghoon Lim

备注：
4 pages, 4 figures, talk in Quark Matter 2014, 19-24 May 2014, Darmstadt, Germany
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摘要：

在RHIC的初始硬散射中，粲夸克和底夸克主要由胶子融合形成，这使它们成为研究整个介质演化的良好探针。在RHIC上的先前测量已经显示在$\sqrt{s_{NN}}=200~{\rm GeV}$的Au+Au碰撞中开放重味强子的大的抑制和方位各向异性。解释同时存在的大量重夸克的抑制和流动一直是一个挑战。为了进一步理解热稠密介质中的重味输运，还必须测量影响重夸克初始分布的冷核物质效应以及末态抑制的系统尺寸依赖性。在这次演讲中，新的测量由PHENIX合作的电子重味衰变在$p$ + $p$，$d$ +金，铜+铜碰撞在$\sqrt{s_{NN}}=200~{\rm GeV}$。特别是，一个令人惊讶的增强中间横向动量重味衰变轻子在$d$ +金在中等和向后的快度也看到在中部中心的Cu+Cu碰撞。这种增强比部分子分布的反阴影的预期要大得多，并且在理论上无法解释。

英文摘要：

Charm and bottom quarks are formed predominantly by gluon fusion in the initial hard scatterings at RHIC, making them good probes of the full medium evolution. Previous measurements at RHIC have shown large suppression and azimuthal anisotropy of open heavy-flavor hadrons in Au+Au collisions at $\sqrt{s_{NN}}=200~{\rm GeV}$. Explaining the simultaneously large suppression and flow of heavy quarks has been challenging. To further understand the heavy-flavor transport in the hot and dense medium, it is imperative to also measure cold nuclear matter effects which affect the initial distribution of heavy quarks as well as the system size dependence of the final state suppression. In this talk, new measurements by the PHENIX collaboration of electrons from heavy-flavor decays in $p$+$p$, $d$+Au, and Cu+Cu collisions at $\sqrt{s_{NN}}=200~{\rm GeV}$ are presented. In particular, a surprising enhancement of intermediate transverse momentum heavy-flavor decay leptons in $d$+Au at mid and backward rapidity are also seen in mid-central Cu+Cu collisions. This enhancement is much larger than the expectation from anti-shadowing of the parton distributions and is theoretically unexplained.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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