Momentum spectra of charmonium produced in a quark-gluon plasma
Momentum spectra of charmonium produced in a quark-gluon plasma
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DOI：
10.1103/physrevc.73.014904
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发表时间：
2005-05
影响因子：
3.1
通讯作者：
R. Thews;M. Mangano
中科院分区：
文献类型：
--
作者：
R. Thews;M. Mangano
我们计算了粲夸克非相干重组在高能重离子碰撞中形成的粲素的速度和横向动量分布。结果对粲夸克的相应分布非常敏感，因此可以作为重离子碰撞中产生的物质状态的探针。在一种极端情况下，我们直接从 pQCD 振幅生成粲对动量，如果可以忽略夸克与介质的相互作用，这是合适的。在另一个极端，我们产生与膨胀介质热平衡的粲夸克动量，适合极强的相互作用。在 BNL 相对论重离子对撞机上，对 Au-Au 相互作用中 J/{psi} 的形成进行了明确的预测。我们发现，对于 pQCD 产生计算中粲夸克动量不变的情况，形成的 J/{psi} 的速度谱和横向动量谱都比不包括介质内形成的情况下预期的要窄得多。特别是，J/{psi} 的平均横向动量在从 pp 到 pA 到 AA 相互作用的过程中将表现出非单调行为。
We calculate rapidity and transverse momentum distributions of charmonium formed in high-energy heavy ion collisions from incoherent recombination of charm quarks. The results are very sensitive to the corresponding distributions of the charm quarks, and thus can serve as a probe of the state of matter produced in the heavy ion collision. At one extreme, we generate charm pair momenta directly from pQCD amplitudes, which are appropriate if one can neglect the interaction of the quarks with the medium. At the other extreme, we generate momenta of charm quarks in thermal equilibrium with the expanding medium, appropriate for an extremely strong interaction. Explicit predictions are made for J/{psi} formation in Au-Au interactions at the BNL Relativistic Heavy Ion Collider. We find that for the case in that charm quark momenta are unchanged from the pQCD production calculation, both the rapidity and transverse momentum spectra of the formed J/{psi} are substantially narrower than would be anticipated in scenarios that do not include the in-medium formation. In particular, the average transverse momentum of the J/{psi} will exhibit a nonmonotonic behavior in the progression from pp to pA to AA interactions.