# Radiative Leptonic B Decays

## Abstract

We present the results of a search for B ^{+} meson decays into γℓ ^{+}v _{ℓ}, where ℓ = e,μ. We use a sample of 232 million B$$\bar{B}$$ meson pairs recorded at the Υ(4S) resonance with the BABAR detector at the PEP-II B factory. We measure a partial branching fraction Δβ in a restricted region of phase space that reduces the effect of theoretical uncertainties, requiring the lepton energy to be in the range 1.875 and 2.850 GeV, the photon energy to be in the range 0.45 and 2.35 GeV, and the cosine of the angle between the lepton and photon momenta to be less than -0.36, with all quantities computed in the Υ(4S) center-of-mass frame. We find Δβ(B ^{+} → γℓ ^{+}v _{ℓ}) = (-0.3 _{1.5} ^{+1.3}(statistical) _{-0.6} ^{+0.6}(systematic) ± 0.1(theoretical)) x 10 ^{-6}, under the assumption of lepton universality. Interpreted as a 90% confidence-level Bayesian upper limit, the result corresponds to 1.7 x 10 ^{-6} for a prior at in amplitude, and 2.3 x 10 ^{-6} for a prior at in branching fraction.

- Authors:

- California Inst. of Technology (CalTech), Pasadena, CA (United States)

- Publication Date:

- Research Org.:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)

- Sponsoring Org.:
- USDOE

- OSTI Identifier:
- 939371

- Report Number(s):
- SLAC-R-900

TRN: US0806760

- DOE Contract Number:
- AC02-76SF00515

- Resource Type:
- Thesis/Dissertation

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; LEPTONS; MESONS; PHASE SPACE; PHOTONS; RESONANCE; Experiment-HEP; HEPEX

### Citation Formats

```
Chen, Edward Tann.
```*Radiative Leptonic B Decays*. United States: N. p., 2007.
Web. doi:10.2172/939371.

```
Chen, Edward Tann.
```*Radiative Leptonic B Decays*. United States. doi:10.2172/939371.

```
Chen, Edward Tann. Mon .
"Radiative Leptonic B Decays". United States.
doi:10.2172/939371. https://www.osti.gov/servlets/purl/939371.
```

```
@article{osti_939371,
```

title = {Radiative Leptonic B Decays},

author = {Chen, Edward Tann},

abstractNote = {We present the results of a search for B+ meson decays into γℓ+vℓ, where ℓ = e,μ. We use a sample of 232 million B$\bar{B}$ meson pairs recorded at the Υ(4S) resonance with the BABAR detector at the PEP-II B factory. We measure a partial branching fraction Δβ in a restricted region of phase space that reduces the effect of theoretical uncertainties, requiring the lepton energy to be in the range 1.875 and 2.850 GeV, the photon energy to be in the range 0.45 and 2.35 GeV, and the cosine of the angle between the lepton and photon momenta to be less than -0.36, with all quantities computed in the Υ(4S) center-of-mass frame. We find Δβ(B+ → γℓ+vℓ) = (-0.31.5+1.3(statistical) -0.6+0.6(systematic) ± 0.1(theoretical)) x 10-6, under the assumption of lepton universality. Interpreted as a 90% confidence-level Bayesian upper limit, the result corresponds to 1.7 x 10-6 for a prior at in amplitude, and 2.3 x 10-6 for a prior at in branching fraction.},

doi = {10.2172/939371},

journal = {},

number = ,

volume = ,

place = {United States},

year = {Mon Jan 01 00:00:00 EST 2007},

month = {Mon Jan 01 00:00:00 EST 2007}

}