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arXiv 1609.04367hep-ph
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用矢量轻夸克解释$R_{K}$和$R_{D^{(*)}}$反常

Explaining the $R_{K}$ and $R_{D^{(*)}}$ anomalies with vector leptoquarks

Suchismita Sahoo, Rukmani Mohanta, Anjan K. Giri

摘要:

最近,$B$工厂BaBar和Belle以及LHCb实验报道了半轻子$B$介子衰变中的几个反常现象,如$R_{K}$和$R_{D^{(*)}}$等.我们考虑了与$b \to s l^+ l^-$和$b \to c l \bar ν_l$跃迁有关的矢量轻夸克来研究这些偏差.利用实验测量的$B_s \to l^+ l^-$、$\bar B \to X_s l^+ l^- (ν\bar ν)$和$B_u^+ \to l^+ ν_l$过程的分支比,对轻夸克参数空间进行了约束.利用受约束的细夸克耦合,我们计算了$\bar B \to D^{(*)} l \bar ν_l$过程的分支比、前后向不对称性、$τ$和$D^*$极化参数。我们发现矢量轻夸克可以同时解释$R_{D^{(*)}}$和$R_K$反常。此外,我们还研究了该模型中罕见的轻子$B_{u, c}^* \to l \barν$衰变过程。

英文摘要:

Recently the $B$ factories BaBar and Belle as well as the LHCb experiment have reported several anomalies in the semileptonic $B$ meson decays such as $R_{K}$ and $R_{D^{(*)}}$ etc. We investigate these deviations by considering the vector leptoquarks relevant for both $b \to s l^+ l^-$ and $b \to c l \bar ν_l$ transitions. The leptoquark parameter space is constrained by using the experimentally measured branching ratios of $B_s \to l^+ l^-$, $\bar B \to X_s l^+ l^- (ν\bar ν)$ and $B_u^+ \to l^+ ν_l$ processes. Using the constrained leptoquark couplings, we compute the branching ratios, forward-backward asymmetries, $τ$ and $D^*$ polarization parameters in the $\bar B \to D^{(*)} l \bar ν_l$ processes. We find that the vector leptoquarks can explain both $R_{D^{(*)}}$ and $R_K$ anomalies simultaneously. Furthermore, we study the rare leptonic $B_{u, c}^* \to l \barν$ decay processes in this model.

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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