Speaker
Description
Several experimental measurements of $b$-decays have suggested the presence of physics beyond the Standard Model (BSM). One set of such measurements are the decay modes $B\to D^{*+}\ell^- \bar{\nu}$ with $\ell = e, \mu,$ and $\tau$. A recent analysis of 2019 Belle data found $\Delta A_{FB} = A_{FB}(B\to D^{*} \mu\nu) - A_{FB} (B\to D^{*} e\nu)$ to be $4.1\sigma$ away from the SM prediction. Improved simulation and analysis tools are needed in order to more effectively probe these new physics (NP) possibilities. We have developed a Monte-Carlo event generator tool based on the EVTGEN framework to simulate NP signatures in $B\to D^{*+}\ell^- \bar{\nu}$, which arise due to the interference between the SM and NP amplitudes. We have also simulated several example NP scenarios which are able to explain the $\Delta A_{FB}$ anomaly, while remaining consistent with experimental constraints. We also show that $\Delta$-type observables allow for definite signals of NP by removing most QCD uncertainties from the form factors, and introduce several correlated observables that allow for more sensitivity to NP.
