Measuring CP violation in $b\to c{\tau }^{-}{\bar{\nu }}_{\tau }$ using excited charm mesons

Abstract

There is growing evidence for deviation from the standard model predictions in the ratios between semi-tauonic and semi-leptonic $B$ decays, known as the $R(D^{(\ast )})$ puzzle. If the source of this non-universality is new physics, it is natural to assume that it also breaks CP symmetry. In this paper we study the possibility of measuring CP violation in semi-tauonic $B$ decays, exploiting interference between excited charm mesons. Given the current values of $R(D^{(\ast )})$, we find that our proposed CP-violation observable could be as large as about 10%. We discuss the experimental advantages of our method and propose carrying it out at Belle II and LHCb.

arXiv comment19 pages, 4 figures

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Cited by in corpus (6)

• A Measurable Angular Distribution for $\bar{B}\to D^{\ast }{\tau }^{-}{\bar{\nu }}_{\tau }$ Decays
• CP Violation in ${\bar{B}}^0\to D^{\ast +}{\mu }^{-}{\bar{\nu }}_{\mu }$
• Signatures of complex new physics in $b\to c\tau \bar{\nu }$ transitions
• Analysis of $b\to c\tau {\bar{\nu }}_{\tau }$ anomalies using weak effective Hamiltonian with complex couplings
• Relations between $b\to c\tau \nu$ Decay Modes in Scalar Models
• Addressing the $R_{\tau /\mu ,e}\left(D^{(\ast )}\right)$ puzzle through New Physics four-fermion operators and their impact on ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$ decay