报告题目：Measurements of photon interactions in hadronic heavy-ion collisions
报 告 人：Shuai Yang
Brookhaven National Laboratory
邀 请 人：易立 教授
报告时间：2018年10月26日(周五) 10：00
报告地点：青岛校区N7 122报告厅
报告摘要：
Strong electromagnetic fields arising from highly charged, relativistic heavy ions can be treated as quasi-real photons. These photons induce a wide variety of photonuclear and photon-photon physics, which were conventionally and extensively studied in ultraperipheral collisions (UPCs). Recently, a significant excess of J/ψ yields at low transverse momenta (pT ) was observed by the ALICE Collaboration in peripheral heavy-ion collisions, qualitatively explained by coherent photonuclear production mechanisms. That explanation implies photon-photon interactions would also occur and contribute to the dilepton production. Since the nuclei are broken in peripheral heavy-ion collisions, it is non-trivial to incorporate the coherence conditions for the aforementioned photon interactions in hadronic heavy-ion collisions. Measurements of e+e− pair production at low pT for different collision systems and energies, discussed in this talk, thus are important to verify and further constrain photon interactions and their possible impacts on emerging phenomena in hadronic heavy-ion collisions.
