| Abstrakt: |
In recent years, the experimental results about the ratio of the branching ratios R D (∗) and R K (∗) , which are in the semileptonic b → c l ν ¯ l and b → s l + l - decays, have been observed to deviate from the Standard Model prediction by 1.4 σ , 2.5 σ , 2.4 σ and 2.2 σ respectively. Motivated by these anomalies and by the abundant B ∗ data samples, we investigate possible New Physics effects of the vector leptoquark in the semileptonic decay B ¯ u , d , s , c ∗ → V τ - ν ¯ τ ( V = D u , d , s ∗ , J / ψ ). which is induced by b → c τ - ν ¯ τ at the quark level. Using the best fit solutions for the new operator Wilson coefficients and the relevant form factors which are obtained in the light-front quark model, we find that (i) the contributions of the vector leptoquark to d Γ (L) / d q 2 ( B ¯ u , d , s , c ∗ → V τ - ν ¯ τ) and R V ∗ (L) (q 2) to be significant; (ii) the two best fit solutions in the vector leptoquark are indistinguishable from each other and give similar amounts of enhancements to these two observables; (iii) both two cases of the vector leptoquark give nearly same results as those of the Standard Model for A FB τ (q 2) , P τ (q 2) and F L ∗ V (q 2) . We hope that the numerical results in this work will be tested in the future high energy experiments. [ABSTRACT FROM AUTHOR] |
