Abstract
We report the first observation of the radiative decay B0→· K0γ using a data sample of 772×106 BB̄ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We observe a signal of 37±8 events with a significance of 5.4 standard deviations including systematic uncertainties. The measured branching fraction is B(B0→·K0γ)= (2.74±0.60±0.32)×10-6, where the uncertainties are statistical and systematic, respectively. We also report the first measurements of time-dependent CP-violation parameters: S ·KS0γ=+0.74-1.05+0.72(stat)-0.24+0.10(syst) and A ·KS0γ=+0.35±0.58(stat)-0.10+0.23(syst). Furthermore, we measure B(B+→·K+γ)=(2. 48±0.30±0.24)×10-6, ACP=-0. 03±0.11±0.08, and find that the signal is concentrated in the M·K mass region near threshold.
| Original language | English |
|---|---|
| Article number | 071101 |
| Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |
| Volume | 84 |
| Issue number | 7 |
| DOIs | |
| State | Published - 6 Oct 2011 |
| Externally published | Yes |