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arXiv 1107.0630hep-phhep-ex
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族非普适Z'模型中的B -> K1 1 ^+1 ^-衰变

B -> K1 l^+l^- Decays in a Family Non-universal Z' Model

Ying Li, Juan Hua, Kwei-Chou Yang

摘要:

研究了族非普适$Z^\prime$模型在$B\to K_{1}(1270,1400)\ell^{+}\ell^{-}(\ell=e\,,μ\,,τ)$衰变中的应用,其中质量本征态$K_{1}(1270,1400)$是$^{1}{P}_{1}$和$^{3}{P}_{1}$的混合态,混合角为$θ$ .在考虑$Z^\prime$玻色子的情况下,通过设定混合角$θ=(-34\pm13)^{\circ}$,分析了各衰变模的分支比、双轻子不变质量谱、归一化前后不对称性和轻子极化不对称性.我们发现$B\to K_{1}(1270)μ^{+}μ^{-}$的所有观测量对$Z^{\prime}$的贡献都很敏感。此外,$B\to K_{1}(1400)μ^{+}μ^{-}$的观测值具有相对较强的$θ$依赖性;因此,混合角$θ$的不确定性将掩盖$Z^{\prime}$的贡献。此外,在低双轻子质量下,$B\to K_{1}(1270)μ^{+}μ^{-}$的FBA谱中的零交叉位置将随着$Z^\prime$的贡献而向正方向移动.对于τ模,由于相空间较小,$Z^\prime$的影响并不显著。这些结果可以在运行中的LHC-b实验和Super-B工厂中得到验证。

英文摘要:

The implications of the family non-universal $Z^\prime$ model in the $B\to K_{1}(1270,1400)\ell^{+}\ell^{-}(\ell=e\,,μ\,,τ)$ decays are explored, where the mass eigenstates $K_{1}(1270,1400)$ are the mixtures of $^{1}{P}_{1}$ and $^{3}{P}_{1}$ states with the mixing angle $θ$. In this work, considering the $Z^\prime$ boson and setting the mixing angle $θ=(-34\pm13)^{\circ}$, 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 $B\to K_{1}(1270)μ^{+}μ^{-}$ are sensitive to the $Z^{\prime}$ contribution. Moreover, the observables of $B\to K_{1}(1400)μ^{+}μ^{-}$ are relatively strong $θ$-dependence; thus, the $Z^{\prime}$ contribution will be buried by the uncertainty of the mixing angle $θ$. Furthermore, the zero crossing position in the FBA spectrum of $B\to K_{1}(1270)μ^{+}μ^{-}$ at low dilepton mass will move to the positive direction with $Z^\prime$ contribution. For the tau modes, the effects of $Z^\prime$ are not remarkable due to the small phase space. These results could be tested in the running LHC-b experiment and Super-B factory.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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