arXiv:1903.10486 [hep-ph]AbstractReferencesReviewsResources
Impact of $D^*$ polarization measurement on solutions to $R_D$-$R_{D^*}$ anomalies
Ashutosh Kumar Alok, Dinesh Kumar, Suman Kumbhakar, S Uma Sankar
Published 2019-03-25Version 1
The anomalies in the flavor ratios $R_D$ and $R_{D^*}$ provide a hint of physics beyond the Standard Model. Previously it was shown that the polarization fraction of the $D^*$ meson in the $B\rightarrow D^*\,\tau\,\bar{\nu}$ decay provides a defining signature for tensor new physics. Recent measurement of this quantity by the Belle collaboration completely rules out the tensor new physics solution (at better than $5\sigma$). Here we do a re-analysis of all the data in $b\rightarrow c\,\tau\,\bar{\nu}$ sector, including the $D^*$ polarization fraction. We identify the allowed new physics solutions and the six variables needed to distinguish between them.