arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1012.2854nucl-thhep-phnucl-ex
收藏

核碰撞中high-pT强子的色透明和抑制

Color transparency and suppression of high-pT hadrons in nuclear collisions

B. Z. Kopeliovich, I. K. Potashnikova, Ivan Schmidt

摘要:

高pT部分子强子化过程中产生的主导(大zh)强子的产生长度lp很短,这是由于过程初期有很强的真空胶子辐射和能量耗散。因此,重离子碰撞中产生的高p_T强子的核抑制的主要部分与无色偶极子在稠密介质中传播的存活几率有关。这是受颜色的透明度,这导致了急剧上升与p_T的核比率R_{AA}(p_T),在良好的协议与最近的数据ALICE实验在LHC,欧洲核子研究中心。除了对介质密度进行调整外,没有进行任何调整,并且发现输运系数为\hat q_0=0.8 GeV^2/fm。这是接近的J/Psi抑制从RHIC数据的分析中提取的值,但比从能量损失方案内的射流淬火数据中发现的值小一个数量级。虽然目前的计算有一个postdiction的状态,机制和所有的公式已经公布,并在这里应用没有修改,除了运动学。同时,在RHIC能区,R_{AA}的p_T依赖性是相当平坦的,这是由于与能量守恒约束有关的抑制因子随x_T的增加而急剧下降。这个因子与LHC的数据无关,因为x_T要小得多。

英文摘要:

The production length l_p of a leading (large z_h) hadron produced in hadronization of a highly virtual high-p_T parton is short because of the very intensive vacuum gluon radiation and dissipation of energy at the early stage of process. Therefore, the main part of nuclear suppression of high-p_T hadrons produced in heavy ion collisions is related to the survival probability of a colorless dipole propagating through a dense medium. This is subject to color transparency, which leads to a steep rise with p_T of the nuclear ratio R_{AA}(p_T), in good agreement with the recent data from the ALICE experiment at LHC, CERN. No adjustment, except the medium density is made, and the transport coefficient is found to be \hat q_0=0.8 GeV^2/fm. This is close to the value extracted from the analysis of RHIC data for J/Psi suppression, but is an order of magnitude smaller than the value found from jet quenching data within the energy loss scenario. Although the present calculations have a status of a postdiction, the mechanism and all formulas have been published, and are applied here with no modification, except the kinematics. At the same time, p_T-dependence of R_{AA} at the energy of RHIC is rather flat due to the suppression factor steeply falling with rising x_T, related to the energy conservation constraints. This factor is irrelevant to the LHC data, since x_T is much smaller.

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。

↑