arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0903.4166nucl-thhep-ph
收藏

重离子碰撞中非光子电子的核修正因子和重味重子介子比

Nuclear modification factor of non-photonic electrons in heavy-ion collisions and the heavy-flavor baryon-to-meson ratio

Yongseok Oh, Che Ming Ko

摘要:

考虑夸克并合模型中产生的重味强子衰变,研究了$\sqrt{s_{NN}^{}} = 200$ GeV的${Au} + {Au}$碰撞中非光子电子的核修正因子$R_{AA}$.虽然一个增强的$Λ_c/D^0$比预测的合并模型,它是在小横动量($\sim 2$ GeV),由于重,轻夸克质量之间的巨大差异达到峰值。结果,增强的$Λ_c/D^0$比,由于$Λ_c$衰变成电子的分支比小于$D^0$的分支比,预期会抑制电子$R_{AA}$,不会导致在大横动量($\ge 5$ GeV)下对电子$R_{AA}$的额外抑制,其中抑制主要是由于产生的夸克-胶子等离子体中的重夸克能量损失。此外,由合并模型预测的增强的$Λ_b/\bar{B}^0$比率对非光子电子$R_{AA}$的影响甚至更小,因为底部重子和介子对于半轻子衰变成电子具有相似的分支比率。

英文摘要:

The nuclear modification factor $R_{AA}$ of non-photonic electrons in ${Au} + {Au}$ collisions at $\sqrt{s_{NN}^{}} = 200$ GeV is studied by considering the decays of heavy-flavor hadrons produced in a quark coalescence model. Although an enhanced $Λ_c/D^0$ ratio is predicted by the coalescence model, it is peaked at small transverse momenta ($\sim 2$ GeV) due to the large difference between heavy and light quark masses. As a result, the enhanced $Λ_c/D^0$ ratio, which is expected to suppress the electron $R_{AA}$ as the branching ratio of $Λ_c$ decay into electrons is smaller than that of $D^0$, does not lead to additional suppression of the electron $R_{AA}$ at large transverse momenta ($\ge 5$ GeV), where the suppression is mainly due to heavy quark energy loss in produced quark-gluon plasma. Also, the enhanced $Λ_b/\bar{B}^0$ ratio predicted by the coalescence model has even smaller effect on the non-photonic electron $R_{AA}$ as bottom baryons and mesons have similar branching ratios for semi-leptonic decays into electrons.

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。

↑