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

我们提出了一个重夸克强子截面的计算程序，它对重离子碰撞中夸克胶子等离子体（QGP）的识别具有重要意义。本程序将包括计算各种强子的反应截面，这些强子已被提议作为QGP诊断探针，如重夸克子、超子和反超子。这些横截面中的大多数目前无法通过实验获得，因此只能使用理论模型进行估计。这个提议的核心部分是使用完善的成分交换模型计算这些横截面，假设标准夸克模型力和之前由我们两人（Barnes和Swanson）开发的malism散射。已知这种方法与现有的实验低能散射数据在广泛的类似强子-强子散射过程中有合理的一致性。将讨论的其他研究课题是多通道和相对论制度的方法的推广，qq对产生振幅的结合，微观和有效拉格朗日描述的比较，以及t矩阵形式化的发展，这将允许直接应用于束缚状态问题。这里得到的横截面对于估计各种强子对夸克-胶子等离子体实验信号的贡献是有用的。这些强子的贡献必须被理解并纳入重离子碰撞的模拟，然后才能通过各种特征建立QGP的形成；因此，我们计划的第三个组成部分是与参与蒙特卡罗模拟RHIC实验的研究人员密切合作，以便这些强子对RHIC的贡献的实验意义可以被评估。在ORNL和田纳西大学，来自phenix的大型RHIC实验组的存在将促进这一工作。

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.