材料期刊网

研究自旋和轨道量子数不同的介子之间的质量劈裂对检验夸克势模型非常重要.在以往的夸克势模型计算中,η_c-J/ψ的质量劈裂都很难达到实验的值.用正规化形状因μ~2/(q~2+μ~2),在对完整的动量空间中的Breit夸克势实施一次正规化下研究了η_c-J/ψ和新介子ηb与Υ(1s)之间的质量劈裂.结果表明,正规化形状因子中的屏蔽质量μ应与介子折合质量有关,当将其展开为介子折合质量的三阶多项式时,上述介子质量劈裂可以精确重现实验的结果.另外,由于完整的Breit 势包含有自旋一轨道耦合相互作用的项,因而还可以研究χ_(c0),χ_(c1)和χ_(c2)之间的质量劈裂.

The study of the splittings between the masses of mesons with different spin and orbit q uantum numbers is important for checking the quark potential model.In the previous calculations with quark po-tential models,the splitting between η_c-J/ψ is however too small to the experimental result.In this pa-per the mass splitting of η_c-J/ψ and the splitting between the new meson ηb and Υ(1s)are investigated with the complete Breit quark potential regularized by applying the form factor μ~2/(q~2+μ~2) one time in momen-tum space.In addition,because the complete Breit potential includes the spin-orbit interaction,it can be used to investigate the splittings among χ_(c0),χ_(c1) and χ_(c2).The investigated results indicate that the screen mass μ in the form factor of regularization is related to the reduced mass of meson.The splittings of-η_c-J/ψ,η_b-Υ(1s),and χ_(c0),χ_(c1) and χ_(c2) can reproduce the experimental results with high accuracy when the screen mass is expanded to the third-order polynomial of meson reduced mass.