Speaker
Suman Kumbhakar
(IIT Bombay)
Description
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. Recently Belle collaboration measured this quantity to be $0.60\pm 0.08 \pm 0.04$. Here we do a re-analysis of all the data in $b\rightarrow c\,\tau\,\bar{\nu}$ sector, including the $D^*$ polarization fraction. We find that the Belle measurement rules out the tensor new physics solutions at 5$\sigma$. We also identify the presently allowed new physics solutions and the six variables needed to distinguish between them.
Authors
Ashutosh Alok
(IIT Jodhpur)
DINESH KUMAR
(IIT BOMBAY)
Suman Kumbhakar
(IIT Bombay)
Sankagiri Umasankar
(IIT Bombay)
