Study of the weak annihilation contributions in charmless $$\varvec{B_s\rightarrow VV}$$ B s → V V decays

Abstract

Abstract In this paper, in order to probe the spectator-scattering and weak annihilation contributions in charmless $$B_s\rightarrow VV$$ B s → V V (where V stands for a light vector meson) decays, we perform the $$\chi ^2$$ χ 2 -analyses for the endpoint parameters within the QCD factorization framework, under the constraints from the measured $$\bar{B}_{s}\rightarrow $$ B ¯ s → $$\rho ^0\phi $$ ρ 0 ϕ , $$\phi K^{*0}$$ ϕ K ∗ 0 , $$\phi \phi $$ ϕ ϕ and $$K^{*0}\bar{K}^{*0}$$ K ∗ 0 K ¯ ∗ 0 decays. The fitted results indicate that the endpoint parameters in the factorizable and nonfactorizable annihilation topologies are non-universal, which is also favored by the charmless $$B\rightarrow PP$$ B → P P and PV (where P stands for a light pseudo-scalar meson) decays observed in previous work. Moreover, the abnormal polarization fractions $$f_{L,\bot }(\bar{B}_{s}\rightarrow K^{*0}\bar{K}^{*0})=(20.1\pm 7.0)\%,(58.4\pm 8.5)\%$$ f L , ⊥ ( B ¯ s → K ∗ 0 K ¯ ∗ 0 ) = ( 20.1 ± 7.0 ) % , ( 58.4 ± 8.5 ) % measured by the LHCb collaboration can be reconciled through the weak annihilation corrections. However, the branching ratio of $$\bar{B}_{s}\rightarrow \phi K^{*0}$$ B ¯ s → ϕ K ∗ 0 decay exhibits a tension between the data and theoretical result, which dominates the contributions to $$\chi _\mathrm{min}^2$$ χ min 2 in the fits. Using the fitted endpoint parameters, we update the theoretical results for the charmless $$B_s\rightarrow VV$$ B s → V V decays, which will be further tested by the LHCb and Belle-II experiments in the near future.