The pure leptonic B decays Bsâ†'e+e(q=d, sande=e,μ,Ï„) are good probes to explore new physics beyond the standard model(SM). In this work,we study the two-body pure leptonic Bs decays in the frame of unparticle physics.Accordding to the knowledge of gauge field theories and effective field theories,we advance an ef-fective interaction modle.In the process of calculation,this paper presents a limit to the effective coupling constant by the experimental data of Bsâ†'μ+μ-.The re-sults show that,the effective coupling constant is depend on du,which is the scaling dimension of the unparticle.Then we calculate the branching ratios of Bsâ†'Ï„+Ï„-by making use of the effective coupling constant prestented earlier.In addition,we calculate the longitudinal polarization asymmetry of leptons in Bsâ†'e+e-(e=μ,Ï„) by selecting proper effective coupling constants,they are also depend on du,and show a certain degree of law. |