Exclusive radiative and electroweak $b\to d$ and $b\to s$ penguin decays at NLO

Abstract.

We provide standard model expectations for the rare radiative decays $B\to K^*\gamma$, $B\to \rho\gamma$ and $B\to\omega\gamma$, and the electroweak penguin decays $B\to K^*\ell^ + \ell^-$ and $B\to\rho \ell^ + \ell^-$ at the next-to-leading order (NLO), extending our previous results to $b\to d$ transitions. We consider branching fractions, isospin asymmetries and direct CP asymmetries. For the electroweak penguin decays, the lepton-invariant mass spectrum and forward-backward asymmetry is also included. Radiative and electroweak penguin transitions in $b\to d$ are mainly interesting in the search for new flavor-changing neutral current interactions, but in addition the $B\to \rho\gamma$ decays provide constraints on the CKM parameters $(\bar\rho,\bar\eta)$. The potential impact of these constraints is discussed.