Branching ratios and CP asymmetries of B{yields}a{sub 1}(1260){pi} and a{sub 1}(1260)K decays
- Department of Physics, Chung Yuan Christian University, Chung-Li, Taiwan 320 (China)
We present the studies of the decays B{yields}a{sub 1}(1260){pi} and a{sub 1}(1260)K within the framework of QCD factorization. Because of the G-parity, unlike the vector meson, the chiral-odd two-parton light-cone distribution amplitudes of the a{sub 1} are antisymmetric under the exchange of quark and antiquark momentum fractions in the SU(2) limit. The branching ratios for a{sub 1}{pi} modes are sensitive to tree-penguin interference. The resultant B(B{sup 0}{yields}a{sub 1}{sup {+-}}{pi}{sup {+-}}) are in good agreement with the data. However, using the current Cabibbo-Kobayashi-Maskawa angles, {beta}=22.0 deg. and {gamma}=59.0 deg., our results for the mixing-induced parameter S and {alpha}{sub eff} differ from the measurements of the time-dependent CP asymmetries in the decay B{sup 0}{yields}a{sub 1}{sup {+-}}{pi}{sup {+-}} at about the 3.7{sigma} level. This puzzle may be resolved by using a larger {gamma} > or approx. 80 deg. For a{sub 1}K modes, the annihilation topologies give sizable contributions and are sensitive to the first Gegenbauer moment of the leading-twist tensor (chiral-odd) distribution amplitude of the a{sub 1} meson. The B{yields}a{sub 1}K amplitudes resemble the corresponding B{yields}{pi}K ones very much. Taking the ratios of corresponding CP-averaged a{sub 1}K and {pi}K branching ratios, we can extract information relevant to the electroweak penguins and annihilations. The existence of new physics in the electroweak penguin sector and final-state interactions during decays can thus be explored.
- OSTI ID:
- 21032552
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 76, Issue 9; Other Information: DOI: 10.1103/PhysRevD.76.094002; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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