入射夸克的能量损失效应  

The energy loss effect of an incoming quark

作　　者：宋丽华[1] 王凤鸣[1] 

机构地区：[1]河北联合大学理学院,河北唐山063009

出　　处：《云南大学学报（自然科学版）》2014年第1期45-50,共6页Journal of Yunnan University(Natural Sciences Edition)

基　　金：国家自然科学基金(11075044);河北省自然科学基金(A2013209299)

摘　　要：借助4套典型的束缚核子部分子分布函数和3种夸克能量损失的表达式,对核Drell-Yan过程中的微分截面比进行了领头阶的唯象分析,确定了入射夸克单位长度的能量损失值dE/dL=(1.21±0.09)GeV/fm.研究结果表明:采用线型的夸克能量损失表达方式和平方型的能量损失表达方式计算所得的核Drell-Yan过程微分截面比的理论曲线无明显差别;与采用的部分子分布函数的类型无关,来自于低能量入射粒子束的实验数据排除了动量分数型的能量损失表达方式.By means of four typical sets of nuclear parton distribution functions and three different parametri- zations of quark energy loss, a leading order phenomenological analysis is performed on the nuclear Drell - Yan differential cross section ratio, and the incoming quark energy loss per unit path length is determined with dE/dL = （ 1.21 ＋ 0.09 ） GeV/fm. Our results show that The theoretical value of the nuclear Drell - Yan differential cross section ratio from the linear energy loss has almost no difference with that given by the quadratic energy loss;with independence on the nuclear modification of parton distributions, the existing experimental data from lower incident beam energy rule out the incident -patton momentum fraction quark energy loss .

关 键 词：DRELL-YAN过程 入射夸克的能量损失 部分子分布函数 

分 类 号：O413[理学—理论物理]