Bound on V + A admixture in the b → c current from inclusive vs . exclusive semileptonic decays of B mesons

Bound on V + A admixture in the b → c current from inclusive vs. exclusive semileptonic decays of B mesons. Abstract An admixture of a right-handed b → c current in the semileptonic weak decays of the B mesons would give a significantly different contribution to the inclusive rate of the decays B → l ν X c as compared to the exclusive decay B → D * l ν at zero recoil. Thus a difference in the values of |V cb | extracted from the data on these two types of decay would measure such admixture. The present marginal mismatch in determination of |V cb | by the two methods can be interpreted as corresponding to g R /g L ≈ 0.14 ± 0.18.