Observation of b → dγ decays and determination of |V_td/V_ts|

The flavor changing neutral current process b → dγ is a sensitive probe to the Standard Model of elementary particle physics. Using a sample of 386 × 10⁶ B meson pairs accumulated by the Belle detector at the KEKB e⁺e⁻ collider, we measure the branching fractions for the exclusive modes B⁻ → ρ⁻γ, B̅⁰ → ρ⁰γ and B̅⁰ → ωγ as follows: B(B⁻ → ρ⁻γ) = 0.55 _−0.36^+0.42_−0.08^+0.09 B(B̅⁰ → ρ⁰γ) = 1.25 _−0.33^+0.37_−0.06^+0.07 B(B̅⁰ → ωγ) = 0.56 _−0.27^+0.34_−0.10^+0.05 where the first error on each value is statistical and the second is systematic. Assuming that these three modes are related by isospin conservation rules, we find the combined branching fraction B(B̅ → (ρ,ω)γ) = 1.32 _−0.31^+0.34_−0.09^0.10. This result is used to determine the ratio of CKM matrix elements, |V_td/V_ts| = 0.199 _−0.025^+0.026_−0.015^0.018.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Physics

Department dc:contributor.department

Physics

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2006

Author dc:creator

• Mohapatra, Debabrata

Chair dc:contributor.committeechair

• Piilonen, Leo E.

Committee members dc:contributor.committeemember

• Ficenec, John R.
• Pitt, Mark L.
• Simonetti, John H.
• Mizutani, Tetsuro

• CKM matrix elements
• rare B decays
• radiative B decays

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-06262006-145012

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/28129