Tuning and validation of hadronic event generator for R value measurements in the tau-charm region

作     者：平荣刚 熊习安 夏磊 高榛 李应天 周兴玉 张丙新 郑波 鄢文标 胡海明 黄光顺 

作者机构：Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Science and Technology of ChinaHefei 230026China University of South ChinaHengyang421001China 

出 版 物：《Chinese Physics C》 (中国物理C（英文版）)

年 卷 期：2016年第40卷第11期

页      面：14-23页

核心收录：

学科分类：07[理学] 070202[理学-粒子物理与原子核物理] 0702[理学-物理学] 

基　　金：Supported by National Natural Science Foundation of China(11175146,11375205,11575077,11335008,11565006) Large Science Setup of Joint Foundation(10979059) 100 Talents Program of CAS 

主　　题：event generator Rvalue 

摘      要：To measure the R value in an energy scan experiment with e＋e- collisions, precise calculation of initial state radiation is required in the event generators. We present an event generator for this consideration, which incorporates initial state radiation effects up to second order accuracy. The radiative correction factor is calculated using the totally hadronic Born cross section. The measured exclusive processes are generated according to their cross sections, while the unknown processes are generated using the LUND Area Law model, and its parameters are tuned with data collected at s = 3.65 GeV. The optimized values are validated with data in the range s = 2.2324--3.671 GeV. These optimized parameters are universally valid for event generation below the DIS threshold.