Radiative $b\to d$ Penguins

TL;DR

This paper reviews recent experimental searches for rare $b o d$ penguin decays at BaBar, finding results consistent with the Standard Model and providing new measurements of related CKM matrix elements.

Contribution

It presents the first evidence of $B^+ o ho^+\gamma$ and offers new measurements of $|V_{td}/V_{ts}|$ independent of $B_s$ mixing.

Findings

No excess observed in $B o ext{pion} ext{lepton} ext{lepton}$ decays.

First evidence of $B^+ o ho^+ ext{gamma}$ decay.

Measurement of $|V_{td}/V_{ts}|$ consistent with SM predictions.

Abstract

This article gives an overview of the recent searches and measurements of $b\to d$ penguin transitions with the BaBar experiment. The branching fraction of these decays in the Standard Model (SM) is expected to be a factor of 10 or more lower than the corresponding $b\to s$ penguin transitions, but a deviation from the SM prediction would be an equally striking sign of new physics. The exclusive decay $B\to\pi\ell\ell$ is searched by BaBar with no excess over the background found. The BaBar measurement of $B\to(\rho,\omega)\gamma$ provides the first evidence of $B^+\to\rho^+\gamma$, is in good agreement with the previous Belle results and provides a measurement of $|V_{td}/V_{ts}|$ independent of the one from $B_s$ mixing. No deviation from the SM is found.