Taming new physics in b → cūd(s) with τ(B+)/τ(Bd) and $$ {a}_{sl}^d $$

Abstract Inspired by the recently observed tensions between the experimental data and the theoretical predictions, based on QCD factorisation, for several colour-allowed non-leptonic B -meson decays, we study the potential size of new physics (NP) effects in the decay channels b → cūd ( s ). Starting from the most general effective Hamiltonian describing the b → cūd ( s ) transitions, we compute NP contributions to the theoretical predictions of B -meson lifetime and of B -mixing observables. The well-known lifetime ratio τ ( B + )/ τ ( B d ) and the experimental bound on the semi-leptonic CP asymmetry $$ {a}_{sl}^d $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mi>a</mml:mi> <mml:mi>sl</mml:mi> <mml:mi>d</mml:mi> </mml:msubsup> </mml:math> , provide strong, complementary constraints on some of the NP Wilson coefficients.