胶子到重夸克偶素的碎裂函数抽取问题讨论  

On the Application of Gluon to Heavy Quarkonium Fragmentation Function

作　　者：戚伟[1] 乔从丰[1] 王建雄[2] 

机构地区：[1]中国科学院研究生院,北京100049 [2]中国科学院高能物理研究所,北京100049

出　　处：《高能物理与核物理》2007年第8期715-718,共4页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金(10491306;10521003;90303005;104750831);中国科学院研究生院科研启动基金(055101BM03)资助~~

摘　　要：分析胶子到重夸克偶素的碎裂函数使用中,不同动量分数z的定义所带来的不确定性,用数值方法计算了常用的非协变z定义所给出的有限胶子动量下g→J/ψ的初始碎裂函数D_g→J/ψ(z,Qo),发现非协变定义给出的碎裂函数对胶子动量k有较大的依赖性.当|k|→∞时,相应碎裂函数趋于光锥定义下的碎裂函数;但k较小时(如在加速器Tevatron和LHC上产生胶子的典型能动量范围内),按非协变形式定义和使用碎裂函数会给计算带来较大的不确定性.We analyze the uncertainties induced by different of gluon to heavy quarkonium fragmentation function. We definitions of the momentum fraction z in the application numerically calculate the initial g → J/ψ fragmentation functions by using the non-covariant definitions of z with finite gluon momentum and find that these fragmentation functions have strong dependence on the gluon momentum k. As ｜k｜→ ∞, these fragmentation functions approach to the fragmentation function in the light-cone definition. We find that when ｜k｜ is small （for instance in the typical energy scale （about 4-20GeV） of the gluon production at the hadron colliders, such as Tevatron and LHC）, large uncertainty remains while the in-covariant definitions of z are employed in the application of the fragmentation functions.

关 键 词：胶子碎裂函数 重夸克偶素 不确定性 

分 类 号：O572.33[理学—粒子物理与原子核物理]