We propose a new method to extract the CKM phase angle γ(≡ φ3) from the isospin analysis in B → Kπ decays only. Unlike previously proposed methods, we do not employ flavor SU(3) symmetry, so that this method is free from the hadronic uncertainty coming from the SU(3) breaking effect. Neither we adopt any Dalitz-plot analysis, which may involve multiple strong phases and large final state interactions. Since no theoretical assumption, except the isospin relations, is imposed on B → Kπ decays, this method will work well, regardless of possible new physics effects unless the isospin relations do not hold. Since the mixing induced CP asymmetry S KS π0 plays a crucial role in this method, more precise measurement on SKS π0 in future experiments will be greatly helpful to extract γ accurately. Using current experimental data for B → Kπ including SKS π0, we extract γ within 1σ: γ = 71-13°+0° or γ = 109-0°+57°.
Bibliographical noteFunding Information:
The work of C.S.K. was supported in part by CHEP-SRC and in part by the KRF Grant funded by the Korean Government (MOEHRD) No. KRF-2005-070-C00030. The work of S.O. was supported by the Second Stage of Brain Korea 21 Project. The work of Y.W.Y. was supported by the KRF Grant funded by the Korean Government (MOEHRD) No. KRF-2005-070-C00030.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics
- Astronomy and Astrophysics