New physics in inclusive semileptonic $B$ decays including nonperturbative corrections

In this work we study the effects of New Physics (NP) operators on the inclusive $\bar{B} \to X_c \tau^- \bar{\nu}_\tau$ decay including power $(\mathcal{O}(1/m_b^2))$ corrections in the NP operators. In analogy with $R(D^{(*)})$ observables, we study the observable $R(X_c)=\frac{\mathcal{B}(\bar{B} \to X_c \tau^- \bar{\nu}_\tau)}{\mathcal{B}(\bar{B} \to X_c \ell^- \bar{\nu}_\ell)}$. We present some numerical results for $R(X_c)$ and compare the results for this observable with and without power corrections in the NP contributions.