# The 2009 Europhysics Conference on High Energy Physics

Jul 16 – 22, 2009
Kraków, Poland
Europe/Warsaw timezone

## Inclusive radiative B meson decays at Belle

Jul 17, 2009, 9:00 AM
15m
Large (Kraków, Poland)

### Large

#### Kraków, Poland

The Auditorium Maximum of the Jagiellonian University 33 Krupnicza Street 31-123 Kraków
Flavour Physics

### Speaker

Bostjan Golob (University of Ljubljana, Jozef Stefan Inst.)

### Description

Improved measurement of inclusive radiative $B$-meson decays We report a fully inclusive measurement of the flavor changing neutral current decay $B\to X_s\gamma$ in the energy range $1.7\,{\rm GeV}\le E^\mathrm{c.m.s.}_\gamma\le2.8\,{\rm GeV}$, covering 97\% of the total spectrum, where c.m.s. is the center of mass system. Using 605 fb$^{-1}$ of data we obtain measurements of the partial branching fraction and first and second moments of the photon energy spectrum for lower energy thresholds including and above $1.7\,{\rm GeV}$. Improved Measurement of the Electroweak Penguin Process $B \to X_s\ell^+\ell^-$ We present a measurement of the branching fraction for the electroweak penguin process $B \to X_s\ell^+\ell^-$, where $\ell$ is an electron or a muon and $X_s$ is a hadronic system containing an $s$-quark. The $X_s$ hadronic system is reconstructed with one $K^{\pm}$ or $K^{0}_{s}$ and up to four pions, where at most one pion can be neutral. The measurement is based on a data sample four times larger than used in the previous analysis, accumulated at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB $e^+e^-$ asymmetric-energy collider.

### Primary author

Bostjan Golob (University of Ljubljana, Jozef Stefan Inst.)