Left-right mixing on leptonic and semileptonic b→u decays

It has been known that there exists a disagreement emerged between the determination of |Vub| from inclusive B→Xuℓν decays and exclusive B→πℓν decays. In order to solve the mismatch, we investigate the left-right (LR) mixing effects, denoted by ξu, in leptonic and semileptonic b→u decays. We find that the new interactions (V+A)×(V−A) induced via the LR mixing can explain the mismatch between the values of |Vub| if Re(ξu)=−(0.14±0.12). Furthermore, we also find that the LR mixing effects can enhance the branching fractions for B→τν and B→ρℓν decays by 30% and 17%, respectively, while reducing the branching fraction for B→γℓν decays by 18%.