Collaborative Research: Heavy-Quark Reaction Cross Sections at RHIC: Studies of Quark-Gluon Plasma Signatures

我们提出了一个计算重夸克强子截面的程序，它对于重离子碰撞中夸克胶子等离子体(QGP)的识别是非常重要的。该程序将涉及到各种被建议作为QGP诊断探针的强子的反应截面的计算，如重夸克子、超子和反超子。这些截面中的大多数目前还不能通过实验获得，因此只能用理论模型来估计。这一建议的中心部分包括使用成熟的组分交换模型计算这些截面，假定标准夸克模型力和我们两个人(Barnes和Swanson)以前发展的散射理论。这种方法对于更大范围的类似强子-强子散射过程，与现有的实验低能散射数据有合理的一致性。其他的研究课题包括多通道和相对论体系的推广，QQ对产生幅度的结合，微观描述和有效拉格朗日描述的比较，以及允许直接应用于束缚态问题的T矩阵形式的发展。对于夸克-胶子等离子体实验信号的各种强子贡献的估算，这里得到的截面应该是有用的。在通过不同的签名建立QGP形成之前，必须理解这些强子贡献并将其纳入重离子碰撞的模拟中；因此，我们计划的第三个组成部分是与参与RHIC实验的蒙特卡罗模拟的研究人员密切合作，以便能够证实这些强子贡献对RHIC的实验意义。这将通过在ORNL和田纳西大学的PHENIX的一个大型RHIC实验小组的存在来促进。

We propose a program of calculations of heavy-quark hadron cross sections which areof great importance in the identifcation of a quark gluon plasma (QGP) in heavy-ion colli-sions. This program will involve the calculation of reaction cross sections of various hadronswhich have been proposed as QGP diagnostic probes, such as heavy quarkonia, hyper-ons, and antihyperons. Most of these cross sections are not accessible experimentally atpresent, and as such can only be estimated using theoretical models. The central compo-nent of this proposal consists of calculations of these cross sections using the well-establishedconstituent-interchange model, assuming standard quark model forces and a scattering for-malism developed previously by two of us (Barnes and Swanson). This approach is known togive reasonable agreement with existing experimental low-energy scattering data for a widerange of analogous hadron-hadron scattering processes. Additional research topics whichwill be addressed are the generalization of the approach to multichannel and relativisticregimes, the incorporation of qq pair production amplitudes, a comparison of microscopicand effective Lagrangian descriptions, and the development of a T-matrix formalism that willallow direct application to bound state problems. The cross sections obtained here shouldbe useful as estimates of the various hadronic contributions to the proposed experimentalsignals for the quark-gluon plasma. These hadronic contributions must be understood andincorporated in simulations of heavy-ion collisions before QGP formation can be establishedthrough various signatures; for this reason a third component of our program is a closecollaboration with researchers involved in Monte-Carlo simulations of RHIC experiments,so that the experimental implications of these hadronic contributions for RHIC can be as-sesssed. This will be facilitated by the presence of a large RHIC experimental group fromPHENIX at ORNL and University of Tennessee.