Scalar form factors in semileptonic heavy-to-light transitions


  报告题目:Scalar form factors in semileptonic heavy-to-light transitions

  报告人: 姚德良博士 西班牙瓦伦西亚大学



  报告摘要:By solving the Muskhelishvili Omnes integral equations, the scalar form factors of the semileptonic D and B meson decays are studied. As inputs, we employ the unitarized amplitudes from chiral effective theory for the energy region not far from thresholds, while, at high energies, proper asymptotic conditions are imposed. The scalar form factors are expressed in terms of the Omnes matrices multiplied by vector polynomials. The lattice QCD results both in the charm and the bottom sectors can be well described simultaneously. Based on our combined fit, the Cabibbo-Kobayashi-Maskawa (CKM) elements of of |Vcd|, |Vcs| and |Vub| are extracted. In addition, we predict the corresponding vector form factors related by chiral SU(3) symmetry, which will serve as alternatives to determine the CKM elements when experimental measurements of the corresponding differential decay rate are available.