Spectrum And The Electric Transitions Of The Charmed-strange Mesons

With the recent decades development of experimental technology,a growing number of new hadron states have been observed.Most of the masses of these newly observed states are in the energy region of the hadron excited states,so it is interesting to search for hadron excited state among these states.At the same time,it is noticed that there has some difficulties when reproduce the mass of some new hadron states in the frame of the quark model,such as the D^*_s0(2317)discovered by the Ba Bar collaboration and the D_s1(2460)observed by the Belle collaboration.In the present thesis,we use the relativistic quark model proposed by Mao-Zhi Yang et al to study the spectroscopy and the wave functions of the charmed strange meson.In partically,the D^*_s0(2317)is considered as the 1³P₀and the D_s1(2460)is considered as the mixture of 1³P₁and the 1¹P₁charmed strange meson.By adjusting the parameters in the relativistic quark model,the mass spectroscopy of charmed strange mesons,including some new charmed strange states,can be well reproduced.We adopt a relativistic quark model to depict the charmed strange meson spectroscopy.By using the wave function and the spectroscopy obtained from the relativistic quark model,we further investigate the electric transitions between the charmed strange mesons.In the present thesis,the partial widths of electric transition can be estimated with three approximations.Fi-nally,the partial widths of the different approximations indicate that for most cases,the long wave length approximation:e^ik·r?1 is reasonable.Moreover,the partial widths calculated by the present model are consistent with the existing experimental values.In addition,our research also provides some guidance for experimental measurements.For examples,our estimations in-dicate that the branch ratio of D_s1(1P₁)?D_s?and D_s1(1P₁)?D_s^*?are relatively large.As for the processes of P?D?and D?P?,the width of some channels are also sizable,which can be accessible for the Belle II and LHCb collaboration.