Scalar Leptoquarks And The Rare Decays ?_b??l~+l~-

Particle physics,also known as high energy physics,is a branch of physics that mainly study the fields and properties of basic particles,interaction and mutual transformation.The standard model of particle physics can successful describe the strong interaction,weak interaction and electromagnetic interaction,almost all theoretical predictions have been tested by high-low energy experiments and success in two aspects of theories and experiments,but it also have some limitations.For example:the existence of the gauge hierarchy problem,cannot explain gravitational interaction?dark matter and dark energy.Therefore,a lot of new physical theories have been proposed in order to solve these problems.Among many new physical theories,the grand unified theory have predict a new particle:Leptoquarks?LQs?.LQs belong to bosons,generally can be divided into scalar and vector.It have the following characteristics:carrying baryon number and lepton number,can coupling with quark and lepton simultaneously.The qualities and the coupling constants of these particles are free parameters,it can only be determined by the quantum correction of the generation and decay of ordinary particles.A lot of works have been done in this area,especially after the successful of LHC Run I,the study of such particles is one of the hot topics in physical theories and experiments.Considering the constraints on the SLQ parameter space from low energy precision mea-surement data,we investigate the correction effects of the SLQs on the physical observables related the rare decays ?_b??l+l-with l = e??and ?.We find that the SLQs can indeed gen-erate the significantly contributions to these rare decays.For the decay ?_b? ?e+e+e-,since the constraints given by the current experimental data on the combination coupling |?³¹?²¹*|/M_LQ²?is very loose,the contributions of the SLQs to Ab ? ?e+e-are too large.For the combina-tion coupling factor |?³²?²²*|/M_LQ² taking the maximal value 5.0 ×10-9GeV-2,the SLQ7 and SLQ1 make the value of the relative correction ?r?Ab? ??+?-?reach 24.4%and 111.1%,respectively.If the branching ratio Br??_b???+??can be precisely measured at the LHCb in near future,the indirect signals of the SLQs might be observed at the LHCb.