Study The Strong Decay Properties Of The X（4140） And Bottom Mesons Within The ³P₀ Model

This paper focuses on the study of mass spectrum and the decay properties of mesons.The aim of the paper is to deepen the understanding of the quark model,explore the properties of charmonium and the bottom mesons,clarify the distribution of some hadronic states in the meson spectrum and make reasonable suggestions for the experimental study of hadrons.Quark model is a fundamental theoretical model of particle physics,this model well explains the composition and properties of many mesons and baryons.Due to its important position in the field of particle physics,it is natural and necessary to exhaust the possible qq or qqq descriptions of the observed states before restoring to the more exotic assignments.Basing on the fundamental ideas of the quark model,this paper systematically introduces the non-relativistic quark model,the relativistic quark model and the ³P₀ model.In these models,the linear potential is replaced by the screening potential,so as to better fit the experimental data and calculate the masses of high excited states.In chapter 3,the mass spectrum of charmonium,charm mesons and charmed-strange mesons are calculated,and the strong decay properties of X_c0（3P）·X_c1（3P）and X_c2（3P）states are analyzed.We get their strong decay channels and their decay widths.Besides,we investigate the mass and strong decay properties of the X（4140）with the assignments of the X_c1（3P）state.We conclude that,the X（4140）,with a small width,could be explained as the charmonium state X_c1（3P）,and the high-precision measurement about the X（4140）could shed light on the nature of the X（4140）.The quantum numbers of this state were J^PC＝1++.Furthermore,we study the bottom mesons in the fourth chapter.we obtain the mass spectra and strong decay properties of bottom mesons.The assignment of B₁（5721）,（?）（5747）,B_J（5840）和B_J（5970）are discussed.Our results show that B₁（5721）and（?）（5747）can be regard as the 1P mixed state and 1³P₂ state respectively.In our results,it is acceptable for BJ（5840）to be 2¹S₀ or 2³S₁ and B_J（5970）to be 1D mixed state or 1³D₃ state.The JP quantum numbers and the Bπ decay mode of the two states will be very important to assign them.We expect more high-precision measurement of bottom mesons.