B→K 1 ℓ + ℓ − decays in a family non-universal Z′ model

European Physical Journal C (Impact Factor: 5.08). 07/2011; 71(10). DOI: 10.1140/epjc/s10052-011-1775-2
Source: arXiv


The implications of the family non-universal Z′ model in the B→K
−(ℓ=e ,μ ,τ) decays are explored, where the mass eigenstates K
1(1270, 1400) are the mixtures of 1P
1 and 3P
1 states with the mixing angle θ. In this work, considering the Z′ boson and setting the mixing angle θ=(−34±13)○, we analyze the branching ratio, the dilepton invariant mass spectrum, the normalized forward–backward asymmetry and lepton polarization asymmetries of each decay mode. We find that all observables of B→K

− are sensitive to the Z′ contribution. Moreover, the observables of B→K

− have a relatively strong θ-dependence; thus, the Z′ contribution will be buried by the uncertainty of the mixing angle θ. Furthermore, the zero crossing position in the FBA spectrum of B→K

− at low dilepton mass will move to the positive direction with Z′ contribution. For the tau modes, the effects of Z′ are not remarkable due to the small phase space. These results could be tested in the running LHC-b experiment and Super-B factory.

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    Journal of High Energy Physics 05/2012; 2012(5). DOI:10.1007/JHEP05(2012)049 · 6.11 Impact Factor
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    ABSTRACT: In this work, within the QCD factorization approach, we investigate the branching fractions and CP asymmetries of decays $B \to K_0^*(1430)\rho$ and $B \to K_0^*(1430)\phi$ under two different scenarios both in the standard model and the family nonuniversal $Z^\prime$ model. We find that the annihilation terms play crucial roles in these decays and lead to the main uncertainties. For decays $B^- \to \bar K_0^{*-} (1430)\rho^0 (\omega)$, the new $Z^\prime$ boson could change branching fractions remarkably. However, for other decays, its contribution might be clouded by large uncertainties from annihilations. Unfortunately, neither the standard model nor $Z^\prime$ model can reproduce all experimental data under one certain scenario. We also noted that the CP asymmetries of $B^-\to \bar K_0^{*-}(1430) \rho^0 (\omega)$ could be used to identify the$K_0^*(1430)$ meson and search for the new physics contribution.
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