分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-09-17
摘要: Orbitally excited L = 1 charm mesons are studied by QCD sum rules in the framework of heavy quark effective theory. The meson masses and the strong decay widths are obtained. This talk is based on our works of refs. 1 and 2 collaborated with Y.B. Dai, C.S. Huang, M.Q. Huang and H.Y. Jin.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2017-09-17
摘要: The 1/Nc expansion of the heavy baryon Isgur-Wise functions is discussed.Because of the contracted SU(2Nf ) light quark spin-flavor symmetry, the universality relations among the Isgur-Wise functions of b ! #3;c and #6;(∗) b ! #6;(∗)c are valid up to the order of 1/N2 c .
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2017-09-17
摘要: The original results for the baryon-pion couplings in the large Nc QCD can be understood in a simpler way in the Hartree-Fock picture. The large Nc relation and its 1/Nc correction between the heavy baryon- meson coupling and the light baryon-meson coupling are emphasized.Application to the baryon-ρ meson interactions is straightforward. The implications of recent experimental result for the strong coupling con-stants of the heavy baryon chiral lagrangian are discussed.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2017-09-17
摘要: We argue that in the large Nc HQET, the masses of the s-wave lowspin heavy baryons equal to the heavy quark mass plus proton mass approximately. To the subleading order, the heavy baryon mass 1/Nc expansion not only has the same form, but also has the same coefficients as that of the light baryon. Based on this, numerical analysis is made.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2017-09-17
摘要: Some phenomenological aspects of a supersymmetric model for fermion mass hierarchy proposed previously are discussed. It is required that the lepton universality violation is near to its current experimental bound. The lepton number violation decay modes τ → 2eμ and 3μ maybe observable in the near future. The Majorana mass of electron-neutrino is predicted to be about 0.1 eV. The fine-tuning problem is discussed.