研究B→PPℓ⁺ℓ⁻和B→PVℓ⁺ℓ⁻衰变中的张量共振贡献
Studying the tensor resonance contributions in $B \to PP\ell^+\ell^-$ and $B \to PV\ell^+\ell^-$ decays
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中文总结 AI 辅助
基于味SU(3)分析研究B→Tℓ⁺ℓ⁻等衰变，通过实验数据和近似方法获分支比，发现有限宽度效应及张量共振态分支比小，其他共振或起主要作用，结果待实验检验。
中文摘要 AI 辅助
我们基于标准模型中的味SU(3)分析，研究了半轻子B→Tℓ⁺ℓ⁻、B→T(→PP)ℓ⁺ℓ⁻和B→T(→PV)ℓ⁺ℓ⁻衰变（其中ℓ = e、μ、τ，T表示轻张量介子，P表示轻赝标介子，V表示轻矢量介子）。B→Tℓ⁺ℓ⁻衰变的强子振幅由非微扰参数关联，通过B⁰s→f′₂(1525)μ⁺μ⁻分支比的实验数据得到B→Tℓ⁺ℓ⁻衰变的所有分支比，再用窄宽度近似并考虑中间共振的有限宽度效应预测B→T(→PP)ℓ⁺ℓ⁻和B→T(→PV)ℓ⁺ℓ⁻衰变的分支比。与窄宽度结果相比，有限宽度效应使多数衰变的分支比略有降低，但在一些近阈值模式中有显著效应。对于亚阈值K₂*(1430)→Kη'相关通道，张量共振的有限宽度能产生非零贡献。与测量的B→PPℓ⁺ℓ⁻和B→PVℓ⁺ℓ⁻衰变相比，含张量共振态的分支比小，其他共振可能对相关衰变起主要作用。结果可在当前和未来实验中检验。
英文摘要
We analyze the semileptonic $B \to T\ell^+\ell^-$, $B \to T(\to PP)\ell^+\ell^-$, and $B \to T(\to PV)\ell^+\ell^-$ decays with $\ell=e,μ,τ$ based on flavor SU(3) analysis in the standard model ($T$ denotes the light tensor meson, $P$ denotes the light pseudoscalar meson, and $V$ denotes the light vector meson). The hadronic amplitudes of the $B \to T\ell^+\ell^-$ decays are related by the nonperturbative parameters, and all branching ratios of the $B \to T\ell^+\ell^-$ decays are obtained by the experimental data of the branching ratio of $B^0_s\to f^{\prime}_{2}(1525)μ^+μ^-$ in three cases, and then the branching ratios of the $B \to T(\to PP)\ell^+\ell^-$ and $B \to T(\to PV)\ell^+\ell^-$ decays are predicted by the narrow width approximation and further considering finite width effects of the intermediate resonances. Compared with the narrow width results, the finite width effects slightly reduce the branching fractions for most decays. However, sizeable finite width effects are found in some near threshold modes. For the subthreshold $K_2^*(1430)\to Kη'$ relevant channels, the finite width of the tensor resonance can open a nonzero contribution. Compared with the measured $B \to PP\ell^+\ell^-$ and $B \to PV\ell^+\ell^-$ decays, we find that the branching ratios with the tensor resonance states are small. Therefore, other resonances, for example, the vector mesons, the scalar mesons, the axial-vector mesons or their excited states, might give the dominant contributions to the relevant decays. Our results might be tested in current and future experiments.
