6533b834fe1ef96bd129df34

RESEARCH PRODUCT

New ways to search for right-handed current inB→ρℓν¯decay

subject

description

An interesting possibility to ease the tension between various determinations of $|{V}_{ub}|$ is to allow a small right-handed contribution to the standard model weak current. The present bounds on such a contribution are fairly weak. We propose new ways to search for such a beyond standard model contribution in semileptonic $B\ensuremath{\rightarrow}\ensuremath{\rho}\ensuremath{\ell}\overline{\ensuremath{\nu}}$ decay. Generalized asymmetries in one, two, or three angular variables are introduced as discriminators, which do not require an unbinned analysis of the fully differential distribution, and a detailed study of the corresponding theoretical uncertainties is performed. A discussion on how binned measurements can access all the angular information follows, which may be useful in both $B\ensuremath{\rightarrow}\ensuremath{\rho}\ensuremath{\ell}\overline{\ensuremath{\nu}}$ and $B\ensuremath{\rightarrow}{K}^{*}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$, and possibly essential in the former decay due to backgrounds. The achievable sensitivity from the available BABAR and Belle data sets is explored, as well as from the anticipated $50\text{ }\text{ }{\text{ab}}^{\ensuremath{-}1}$ Belle II data.