Bs,d ? ?+?? decays in a flavor changing Z' model

We study the pure leptonic decays Bs,d ? ?+?? in a Flavor Changing Z' Model. From the recent measurements of the branching ratios ?(Bs,d ? ?+??), we have derived the bounds on the effective ?-?-Z' lepton coupling BL??. We find that, (i) if neglecting the contribution from the right-handed lepton coupling BR??, we obtain 1.32 < BL?? < 3.32; (ii) if considering the contribution from the right-handed lepton coupling BR?? and setting BL?? = BR??, we obtain 0.99 < BL?? < 2.19. Our results could be useful for researching Z' effects.