Strange Heavy Light Meson's Mass Spectra And Radiative Transition

Recently, many experiment groups such as LHCb Belle ? have discovered ?,Dsmesons and their high excited states. These meson always consist of one heavy quark and one light antiquark, usually called heavy-light meson. In this thesis, we use semi-relativistic potential model to calculate the mass spectra and radiative transitions of these mesons, the model potential includes the long-distance linear confining interaction term, the short-distance one-gluon-exchange?OGE? Coulomb interaction, and the spin-dependent interaction. The calculation is given for mass spectra of B_s, B_s^*, and their high excited states. We use radial wave function to calculate the radiative transition between states for which the selection rules are satisfied. It is found that the results of mass spectra is consistent with experiment. Compared with Godfrey-Isgur?GI? model, some improve-ments is achieved. Our results show that for the decay B_s 2P'₁?6150??B_s 1³S₁?5400?? the partial width can reach up 65keV, which can be tested by the forthcoming research on Belle ?. This thesis content is arranged as below:In the first chapter we briefly introduce the background of this study and some related knowledge that will be used later, which include the standard model, particle classification and Godfrey-Isgur?GI? model, Cornell model.In the second chapter we studied in detail the theoretic framework of calculating mass spectra and radiative transitions for heavy light mesons. We apply using the first order pertubation method of semi-relativistic potential model to deduce the formula of heavy light mesons. The derivation of second quantization of radiative transition?E1, M1? formulas. We note that the spectator hypothesis is assumed in the process to find the radiative transition formula.In the third chapter we numerically study the mass spectra and radiative transition of strange heavy light meson such as Ds, B_s, D^*s, B^*s and their excited states, the theoretical results of mass spectra and partial widths of radiative transition for 35,2P,2D excited states are obtained, and compared to that in the PDG?particle data group? for 2014 and the results predictions of Godfrey-Isgur?GI? model. Some improvements on meson spectrum have been made when compared with Godfrey-Isgur?GI? model, especially for the cases D_s0^*?2317?0, B_s.In the fourth chapter, we summarize the main results and give an outlook of this studv in the future.