Breit夸克势的不同次正规化与η_c-J/ψ等的质量劈裂  

Different time regularization of the Breit quark potential and the mass splittings of η_c-J/ψ and other mesons

作　　者：吉日木图[1] 敖登[1] 包特木尔巴根[2] 

机构地区：[1]内蒙古医科大学计算机信息学院,呼和浩特010110 [2]内蒙古民族大学物理与电子信息学院,通辽028043

出　　处：《物理学报》2016年第4期39-45,共7页Acta Physica Sinica

基　　金：内蒙古自然科学基金(批准号:2011MS0116);内蒙古高校科学研究项目(批准号:NJZY11116)资助的课题~~

摘　　要：用夸克势模型研究结构相同而自旋和轨道量子数不同的介子之间质量劈裂是检验势模型有效性的重要手段之一.在以往的用各种夸克势模型计算质量劈裂工作中,当轻介子和重介子一起计算时,-很容易劈裂,而η_c-J/ψ等的劈裂都很难达到实验值.这里首先用正规化形状因子μ~2/(q^2+μ~2),对完整的动量空间中的Breit夸克势的第三项实施二次正规化,除了第一项库仑势和第七项常数项势,对其余的项实施一次正规化,然后用来计算质量劈裂.研究计算发现,只有当屏蔽质量μ取为关于折合质量μ_r=m_im_j/(m_i+m_j)的三阶多项式时,轻介子π-ρ和重介子η_c-J/ψ,η_b-γ(1s),还有χ_(c0)-χ_(c1)-χ_(c2)等的劈裂精确达到实验值,同时其他介子质量也都比以往得到较大的改善.因此,本文给出了一个有效的夸克势模型.The study on the mass splittings of the mesons with the same structure but different spin- and orbit-quantum numbers is one of the important methods for checking the efficiency of potential models. In previous calculations for quark potential models, the splitting between ^-p is easily obtained while that of the ~c-J/~ is however too small to meet the experimental results. In this paper, the third term of the complete Breit quark potential in the momentum space is regularized twice by applying the form factor ~2/（q2 ~ #2）, and the other terms except the first term of the Coulombic potential and the seventh term of the constant potential are regularized once. The mass splittings are calculated by using these values. Our results indicate that the mass splittings of light mesons π-p, heavy mesons ηc-J/ψ, ηb-γ（1s）, and χc0-χc1-χc2 can meet the experimental results with high accuracy only when the screen mass μ is expanded to the third-order polynomial with respect to the meson reduced mass μr = mimj/（mi ＋ mj）, while the masses of other mesons are improved greatly. An efficient quark potential model is thus described in this paper.

关 键 词：非相对论夸克势模型 介子束缚态 正规化 质量劈裂 

分 类 号：O572.33[理学—粒子物理与原子核物理]