2007/04/30 by Hai-Yang Cheng, Chun-Khiang Chua, Amarjit Soni · 4 citations
Physics and Astronomy · #Atomic and Subatomic Physics Research #B meson #Branching fraction #Factorization #Meson #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Scalar (mathematics) #Scalar meson #Vector meson #hep-ex #hep-ph
paper · pdf · doi:10.1103/physrevd.76.094006
published as Phys.Rev.D76:094006,2007 · 39 pages, 2 figures, version to appear in PRD
arxiv created 2007/10/02 · openalex publication_date 2007/11/02 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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\ensuremath→P1P2 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^\ensuremath-\ensuremathαNRpB\ifmmode⋅\else\textperiodcentered\fi(pi+pj) so that the HMChPT results are recovered in the soft meson limit pi,pj\ensuremath→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 B0\ensuremath→KSKSKS or B^\ensuremath-\ensuremath→K^\ensuremath-KSKS. 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+K^\ensuremath-KS(L), K+K^\ensuremath-K^\ensuremath- and K^\ensuremath-KSKS modes are consistent with the data within errors. (ii) Although the penguin-dominated B0\ensuremath→K+K^\ensuremath-KS decay is subject to a potentially significant tree pollution, its effective sin2\ensuremathβ is very similar to that of the KSKSKS mode. However, direct CP asymmetry of the former, being of order \ensuremath-4%, is more prominent than the latter. (iii) For B\ensuremath→K\ensuremathπ\ensuremathπ decays, we found sizable nonresonant contributions in K^\ensuremath-\ensuremathπ+\ensuremathπ^\ensuremath- and K0\ensuremathπ+\ensuremathπ^\ensuremath- modes, in agreement with the Belle measurements but larger than the BABAR result. (iv) Time-dependent CP asymmetries in KS\ensuremathπ0\ensuremathπ0, a purely CP-even state, and KS\ensuremathπ+\ensuremathπ^\ensuremath-, an admixture of CP-even and CP-odd components, are studied. (v) The \ensuremathπ+\ensuremathπ^\ensuremath-\ensuremathπ0 mode is found to have a rate larger than \ensuremathπ+\ensuremathπ^\ensuremath-\ensuremathπ^\ensuremath- even though the former involves a \ensuremathπ0 in the final state. They are both dominated by resonant \ensuremathρ contributions. (vi) We have computed the resonant contributions to 3-body decays and determined the rates for the quasi-two-body decays B\ensuremath→VP and B\ensuremath→SP. The predicted \ensuremathρ\ensuremathπ, f0(980)K and f0(980)\ensuremathπ rates are in agreement with the data, while the calculated \ensuremathφK, K*\ensuremathπ, \ensuremathρK and K0*(1430)\ensuremathπ are in general too small compared to experiment. (vii) Sizable direct CP asymmetry is found in K+K^\ensuremath-K^\ensuremath- and K+K^\ensuremath-\ensuremathπ^\ensuremath- modes.