Nonperturbative Study On The Scalar K₀^*（1430） Meson Leading-Twist Distribution Amplitude And B_s,D_s→K₀^*（1430）lν_l Semileptonic Decays

The current research on scalar K₀^*（1430）meson is mainly based on two schemes,Scheme 1（S1）:the scalar K₀^*（1430）meson is assumed to be the ex-cited state corresponding to the ground state at 1 Ge V;Scheme 2（S2）:the scalar K₀^*（1430）meson is considered as the ground state.This work is based on the（S2）and mainly study the leading-twist distribution amplitude（DA）φ_2;K0*（x,μ）of the scalar K₀^*（1430）meson,and further study the scalar K₀^*（1430）meson tran-sition form factor and the corresponding semileptonic decays.At present,the leading-twist distribution amplitudeφ_2;K0*（x,μ）of the scalar K₀^*（1430）meson mainly relies on the TF model of distribution amplitude（truncated form of the Gegenbauer expansion series）.However,a simple TF model is not sufficient to accurately describe the behavior of distribution amplitude.Therefore,We study the K₀^*（1430）meson leading-twist distribution amplitudeφ_2;K0*（x,μ）with the QCD sum rules in the framework of background field theory.In the specific cal-culation,we are based on the scenario that the K₀^*（1430）meson is viewed as the groud state of sˉq or qˉs.Based on this scenario,this work first calculated theξ-moments sum rule of the leading-twist distribution amplitude of the scalar K₀^*（1430）meson.In consideration of the sum rule ofξ-moments?ξ⁰?_3;K0*cannot be normalized in whole Borel region,a more reasonable sum rule formula forξ-moments?ξⁿ?2;K₀*is suggested in paper,and calculated numerical results of the first tenξ-moments,?ξⁿ?2;K₀*（n=1,2,...,10）.Meanwhile,a new light-cone harmonic oscillator（LHCO）model for K₀^*（1430）meson leading-twist distribu-tion amplitude is established for the first times.By fitting the resulted values of?ξⁿ?2;K₀*（n=1,2,...,10）via the least square method,and obtained the behavior ofφ_2;K0*（x,μ）In addition,we study the transition form factors and the corresponding semileptonic decays process of the K₀^*（1430）meson based on the light-cone sum rules.In the specific calculation,the traditional flow method is adopted based on the two-point correlation function,obtained the expression of the distribution amplitude of the K₀^*（1430）meson twist-2,3,and further obtain the numerical results of the B_s,D_s→K₀^*（1430）transition form factor and the branching ratio of the semileptonic decay B_s,D_s→K₀^*（1430）lν_l.The transition form factor is an important parameter for extract CKM matrix elements.The corresponding numerical results can be used to extract the CKM matrix elements by combining the relative experimental data in the future.