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Title: Charmless three-body decays of B mesons

Journal Article · · Physical Review. D, Particles Fields
 [1];  [2];  [3]
  1. Institute of Physics, Academia Sinica, Taipei, Taiwan 115 (China)
  2. Department of Physics, Chung Yuan Christian University, Chung-Li, Taiwan 320 (China)
  3. Physics Department, Brookhaven National Laboratory, Upton, New York 11973 (United States)

An exploratory study of charmless 3-body decays of B mesons is presented using a simple model based on the framework of the factorization approach. The nonresonant contributions arising from B{yields}P{sub 1}P{sub 2} transitions are evaluated using heavy meson chiral perturbation theory (HMChPT). The momentum dependence of nonresonant amplitudes is assumed to be in the exponential form e{sup -{alpha}{sub N}{sub R}}{sup p{sub B}{center_dot}}{sup (p{sub i}+p{sub j})} so that the HMChPT results are recovered in the soft meson limit p{sub i},p{sub j}{yields}0. In addition, we have identified another large source of the nonresonant signal in the matrix elements of scalar densities, e.g. <KK|ss|0>, which can be constrained from the decay B{sup 0}{yields}K{sub S}K{sub S}K{sub S} or B{sup -}{yields}K{sup -}K{sub S}K{sub S}. The intermediate vector-meson contributions to 3-body decays are identified through the vector current, while the scalar meson resonances are mainly associated with the scalar density. Their effects are described in terms of the Breit-Wigner formalism. Our main results are: (i) All KKK modes are dominated by the nonresonant background. The predicted branching ratios of K{sup +}K{sup -}K{sub S(L)}, K{sup +}K{sup -}K{sup -} and K{sup -}K{sub S}K{sub S} modes are consistent with the data within errors. (ii) Although the penguin-dominated B{sup 0}{yields}K{sup +}K{sup -}K{sub S} decay is subject to a potentially significant tree pollution, its effective sin2{beta} is very similar to that of the K{sub S}K{sub S}K{sub S} mode. However, direct CP asymmetry of the former, being of order -4%, is more prominent than the latter. (iii) For B{yields}K{pi}{pi} decays, we found sizable nonresonant contributions in K{sup -}{pi}{sup +}{pi}{sup -} and K{sup 0}{pi}{sup +}{pi}{sup -} modes, in agreement with the Belle measurements but larger than the BABAR result. (iv) Time-dependent CP asymmetries in K{sub S}{pi}{sup 0}{pi}{sup 0}, a purely CP-even state, and K{sub S}{pi}{sup +}{pi}{sup -}, an admixture of CP-even and CP-odd components, are studied. (v) The {pi}{sup +}{pi}{sup -}{pi}{sup 0} mode is found to have a rate larger than {pi}{sup +}{pi}{sup -}{pi}{sup -} even though the former involves a {pi}{sup 0} in the final state. They are both dominated by resonant {rho} contributions. (vi) We have computed the resonant contributions to 3-body decays and determined the rates for the quasi-two-body decays B{yields}VP and B{yields}SP. The predicted {rho}{pi}, f{sub 0}(980)K and f{sub 0}(980){pi} rates are in agreement with the data, while the calculated {phi}K, K*{pi}, {rho}K and K{sub 0}*(1430){pi} are in general too small compared to experiment. (vii) Sizable direct CP asymmetry is found in K{sup +}K{sup -}K{sup -} and K{sup +}K{sup -}{pi}{sup -} modes.

OSTI ID:
21032556
Journal Information:
Physical Review. D, Particles Fields, Vol. 76, Issue 9; Other Information: DOI: 10.1103/PhysRevD.76.094006; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
Country of Publication:
United States
Language:
English