$$b \rightarrow c \tau \nu _{\tau }$$ b→cτντ Decays: a catalogue to compare, constrain, and correlate new physics effects

• Main Authors: Srimoy Bhattacharya, Soumitra Nandi, Sunando Kumar Patra
• Format: Article
• Language: English
• Published: SpringerOpen 2019-03-01
• Series: European Physical Journal C: Particles and Fields
• Online Access: http://link.springer.com/article/10.1140/epjc/s10052-019-6767-7

Abstract In this article, we predict the standard model (SM) values of the asymmetric and angular observables in $$B\rightarrow D^{(*)}\tau \nu _{\tau }$$ B→D(∗)τντ decays, using the results of the new up-to-date analysis in $$B\rightarrow D^{(*)}\ell \nu _{\ell }$$ B→D(∗)ℓνℓ . We also revisit the SM prediction of the inclusive ratio $${\mathcal {R}}_{X_c}$$ RXc , and we give its values in different schemes of the charm quark mass. This is the first analysis which includes all the known corrections in the SM. In addition, we analyze the $$b\rightarrow c\tau \nu _\tau $$ b→cτντ decay modes in a model-independent framework of effective field theory beyond the standard model. Considering all the possible combinations of the effective operators in $$b \rightarrow c \tau \nu _{\tau }$$ b→cτντ decays and using the Akaike information criterion, we find the scenarios which can best explain the available data on these channels. In the selected scenarios, best-fit values and correlations of the new parameters are extracted. Using these results, predictions are made on various observables in the exclusive and inclusive semitaunic $$b \rightarrow c $$ b→c decays. The graphical correlations between these observables are shown, which are found to be useful in discriminating various new physics scenarios.