Testing the Standard Model with CP-asymmetries in flavour-specific non-leptonic decays

TL;DR

This paper explores using CP asymmetries in flavour-specific non-leptonic B decays to test the Standard Model and identify potential new physics effects, emphasizing the precision measurement prospects at LHCb.

Contribution

It proposes a novel approach to study CP asymmetries in non-leptonic decays sensitive to BSM contributions, highlighting their potential to reveal new physics.

Findings

CP asymmetries in these decays can indicate BSM effects.

LHCb can precisely measure CP asymmetry in B_s  D_s^+    decays.

Standard Model predictions have low uncertainties, making deviations significant.

Abstract

Motivated by recent indications that the rates of colour-allowed non-leptonic channels are not in agreement with their Standard Model expectations based on QCD factorisation, we investigate the potential to study CP asymmetries with these decays. In the Standard Model, these flavour-specific decays are sensitive to CP violation in $B^0_{(s)}$--$\bar{B}^0_{(s)}$ mixing, which is predicted with low uncertainties and can be measured precisely with semileptonic decays. If there are beyond Standard Model contributions to the non-leptonic decay amplitudes, there could be significant enhancements to the CP asymmetries. Measurements of these quantities therefore have potential to identify BSM effects without relying on Standard Model predictions that might be affected by hadronic effects. We discuss the experimental prospects, and note the excellent potential for a precise determination of the CP asymmetry in $\bar{B}_s \to D_s^+ \pi^-$ decays by the LHCb experiment.