New Physics in inclusive $\bar{B} \to X_c \ell \bar{\nu}$ decays

TL;DR

This paper performs a comprehensive fit of inclusive B meson decay data to test for New Physics effects, finding no significant evidence but setting competitive bounds on possible new interactions.

Contribution

First global phenomenological fit of inclusive B decay observables allowing for generic dimension-six New Physics interactions in the Weak Effective Theory.

Findings

No significant preference for New Physics found.

Bounds on Wilson Coefficients are competitive with those from exclusive decay modes.

Inclusion of power and perturbative QCD corrections up to specified orders.

Abstract

We present the first global phenomenological fit of inclusive $\bar B\to X_c\ell\bar\nu$ observables to all available experimental data allowing for generic dimension-six New Physics interactions in the Weak Effective Theory. The fit includes both New Physics Wilson coefficients and non-perturbative QCD parameters. New Physics contributions are calculated including power corrections up to $\mathcal O(\Lambda_{\rm QCD}^3/m_b^3)$ and perturbative QCD corrections up to $\mathcal O(\alpha_s)$. We find no significant preference for New Physics and obtain bounds on the size of the relevant Wilson Coefficients competitive with those coming from exclusive modes.