Speaker
Rusa Mandal
(The Institute of Mathematical Sciences)
Description
The decay mode $B\to K^* \ell^+\ell^-$ results in the measurement of a large
number of related observables by studying the angular distribution of the decay
products and is regarded as a sensitive probe of physics beyond the standard
model. Recently, LHC$b$ has measured several of these observables using
$3 \text{fb}^{-1}$ data, as a binned function of $q^2$, the dilepton invariant mass
squared. We show how data can be used without any approximations to extract
theoretical parameters describing the decay and to obtain a relation amongst
observables within the standard model. We find three kinds of significant
disagreement between theoretical expectations and values obtained by fits. The
values of the form factors obtained from experimental data show significant
discrepancies when compared with theoretical expectations in several $q^2$ bins.
We emphasize that this discrepancy cannot arise due to resonances and
non-factorizable contributions from charm loops. Further, a relation between
form factors expected to hold at large $q^2$ is very significantly violated.
Finally, the relation between observables also indicates some deviations in the
forward-backward asymmetry in the same $q^2$ regions.
These discrepancies are possible evidence of physics beyond the standard model.
Primary author
Rusa Mandal
(The Institute of Mathematical Sciences)
Co-author
Rahul Sinha
(T)
