e^+e^-湮没中轻夸克碎裂为粲介子的研究  

Fragmentation of Light Initial Quarks into Charm Measons in e^+ e^- Annihilation

作　　者：金毅[1] 李世渊[1] 谢去病[1] 

机构地区：[1]山东大学物理与微电子学院,济南250100

出　　处：《高能物理与核物理》2003年第10期852-856,共5页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金(10075031;10205009)~~

摘　　要：研究了e^+e^-湮没中“初始”轻夸克和胶子劈裂产生的(?)组合为(?)介子(包括D^-,D_s^-,(?)~0)或(?)~*介子(包括D^(*-),D_s^(*-),(?)^(*0))的过程。发现尤其在s^(1/2)=M_Z处,其产额相对较大,当限制(?)或(?)~*的能量大于20GeV时,它和c夸克碎裂产物的不变质量谱在稍大于2M_(?)附近有一个峰,这是该过程区别于其它(?)或(?)~*介子产生过程的显著特征。此过程产生的矢量介子基本上是纵向极化的,与实验上观测到的(?)~*介子的纵向极化一致。We study the process that the light initial quarks produced in e+ e- annihilation combine with the c from glu-on splitting to form D's (D-+D6-+D0) or D 's(D-*+ Ds*-+D*0). The 'light + heavy' bound state is described by light-cone wavefunction. The contribution of this process to D (D ) production at Z0 pole is much larger compared with that in lower energies (e.g. 10.6GeV) . For this special process, the invariant mass of D(D ) and the charm had-ron fragmented from the c quark has a unique spectrum which peaks near 2 MB if we constrain the D(D*) from all processes with energy larger than 20GeV. It is also noticeable that the produced D* in this process is dominantly longitudinally polarized, which is consistent with the OPAL data.

关 键 词：重夸克 粲介子 光锥波函数 不变质量谱 WP比 矢量介子极化 E^+E^-湮没 轻夸克 碎裂 QCD 量子色动力学 

分 类 号：O572.3[理学—粒子物理与原子核物理]