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arXiv 0907.1214nucl-ex
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相对论性重离子碰撞中双光子相互作用与核破裂

Two-Photon Interactions with Nuclear Breakup in Relativistic Heavy Ion Collisions

Anthony J. Baltz, Yuri Gorbunov, Spencer R. Klein, Joakim Nystrand

摘要:

高电荷态相对论重离子具有高的双光子相互作用截面。光子通量足够高,双光子相互作用可能伴随着额外的光核相互作用。除了共有的碰撞参量外,这些相互作用是独立的。其他的相互作用,如相互库仑激发是实验的兴趣,因为来自核解离的中子提供了一个简单的,相对无偏的触发。计算了$γγ$产生介子和轻子对以及伴随相互库仑离解的$γγ$反应的截面、快度、质量和横动量($p_T)$)分布.伴随多中子发射($XnXn$)和单中子发射($1n1n$)的$γγ$相互作用截面约为无伴随$γγ$相互作用截面的1/10和1/100。我们讨论的准确性,这些横截面可以计算。$γγ$末态的典型$p_T$比可比较的相干光核相互作用小几倍,因此$p_T$可能是分离这两类相互作用的有效工具。

英文摘要:

Highly charged relativistic heavy ions have high cross-sections for two-photon interactions. The photon flux is high enough that two-photon interactions may be accompanied by additional photonuclear interactions. Except for the shared impact parameter, these interactions are independent. Additional interactions like mutual Coulomb excitation are of experimental interest, since the neutrons from the nuclear dissociation provide a simple, relatively unbiased trigger. We calculate the cross sections, rapidity, mass and transverse momentum ($p_T)$ distributions for exclusive $γγ$ production of mesons and lepton pairs, and for $γγ$ reactions accompanied by mutual Coulomb dissociation. The cross-sections for $γγ$ interactions accompanied by multiple neutron emission ($XnXn$) and single neutron emission ($1n1n$) are about 1/10 and 1/100 of that for the unaccompanied $γγ$ interactions. We discuss the accuracy with which these cross-sections may be calculated. The typical $p_T$ of $γγ$ final states is several times smaller than for comparable coherent photonuclear interactions, so $p_T$ may be an effective tool for separating the two classes of interactions.

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。

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