夸克质量对正负电子湮灭中单举过程和遍举过程的影响  

The effect of quark mass on the exclusive and inclusive processes in e^+e^- annihilation

作　　者：祁烁[1] 王丽芝[1] 刘魁勇[2] 成泰民[1] 

机构地区：[1]沈阳化工学院数理系,辽宁沈阳110142 [2]辽宁大学物理系,辽宁沈阳110036

出　　处：《辽宁师范大学学报（自然科学版）》2008年第1期40-43,共4页Journal of Liaoning Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目(10647138);辽宁省教育厅科学技术研究项目(20060667)

摘　　要：在3种方案下考虑夸克质量改变对正负电子湮灭中双粲夸克对的单举过程和遍举产生的影响.第一种方案,选取固定长程矩阵元;第二种方案,采用线性势模型计算长程矩阵元;第三种方案,由实验抽取长程矩阵元.我们发现在第一种方案下,夸克质量改变对单举过程和遍举过程的产生截面都有显著影响.当夸克质量取1.0 GeV时,单举过程的领头阶计算可以与实验值符合得很好.但两者比值随夸克质量减小与实验值的偏差变大.在第二种方案和第三种方案下,随夸克质量的减小,虽然单举过程的截面有显著增大,但遍举过程的截面随夸克质量的减小而减小.In this paper, the effect of quark mass on the exclusive and inclusive processes in e＋ e- annihilation is investigated in three schemes. In the first scheme, the fixed long-distance matrix was chosen. In the second scheme, the fixed long-distance matrix was calculated through a linear potential model. In the third scheme, the fixed long-distance matrix was extracted from experimental data. In the first scheme, the cross sections both of the inclusive and the exclusive processes increased significantly with the quark mass decreasing. When the charm quark mass is 1.0 GeV, the cross section of inclusive process agrees with the experimental data. However, the ratio of them in exclusive process and inclusive processes can not coincide with the experimental data. In the second and the third schemes, though the cross section of the inclusive process increased with the quark mass decreasing, the cross section of the exclusive process decreased with the quark mass decreasing.n

关 键 词：非相对论量子力学 粲夸克偶素 遍举过程 单举过程 

分 类 号：O412.3[理学—理论物理]