$B$ anomalies with unparticles

Abstract

We analyze the $B$ anomalies associated with the $B\to D^{(\ast )}\tau \nu$ decays in the unparticle model. The fraction of the branching ratios $R(D^{(\ast )})$ and other parameters related to the polarization are fitted to the experimental data by minimizing ${\chi }^2$. The best-fit values are $R(D{)}_{\mathrm{best}}=0.371$ and $R(D^{\ast }{)}_{\mathrm{best}}=0.266$ which are still larger than the standard model predictions. We find that our results safely render the branching ratio $\mathrm{Br}(B_c\to \tau \nu )$ below $10\%$.

Comments: 14 pages, 2 figures