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arXiv 2201.11393hep-phhep-ex
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$b\to cτ\barν_{e,μ}$对$R(D^{(*)})$的贡献

$b\to cτ\barν_{e,μ}$ contributions to $R(D^{(*)})$

Shikma Bressler, Federico De Vito Halevy, Yosef Nir

摘要:

$R(D^{(*)})$之谜代表$\sim3σ$违反了$B\to D^{(*)}τν$和$B\to D^{(*)}\ellν$衰变率之间的轻子味普适性,其中$\ell=e,μ$。如果用新物理学来解释的话,一般来说,没有理由认为相关的中微子分别是$ν_τ$和$ν_\ell$。我们研究是否$τ$相关率可以提高显着的贡献$B\to D^{(*)}τν_\ell$从标准模型有效场论(SMEFT)的一类运营商。我们发现禁戒介子衰变或稀有介子衰变的上界意味着轻子味破坏过程的贡献不超过所需位移的PDMATHAMV。然而,新的物理学不需要微调口味的调整。寻找相关的高- $p_T$过程$pp\toτ^\pmμ^\mp$目前可以把一个较低的边界上的轻子味违反新的物理,这是一个因素的$2.2$弱于介子衰变的边界。我们的结论的一个例外是由标量和张量SMEFT算子的特定组合引起的。

英文摘要:

The $R(D^{(*)})$ puzzle stands for a $\sim3σ$ violation of lepton flavor universality between the decay rates of $B\to D^{(*)}τν$ and $B\to D^{(*)}\ellν$, where $\ell=e,μ$. If it is accounted for by new physics, there is no reason in general that the relevant neutrinos are, respectively, $ν_τ$ and $ν_\ell$. We study whether the $τ$ related rate could be enhanced by significant contributions to $B\to D^{(*)}τν_\ell$ from a class of operators in the Standard Model Effective Field Theory (SMEFT). We find the upper bounds from forbidden or rare meson decays imply that the contributions from the lepton flavor violating processes account for no more than about $4\%$ of the required shift. Yet, no fine-tuned flavor alignment is required for the new physics. Searching for the related high-$p_T$ process $pp\toτ^\pmμ^\mp$ can at present put a lower bound on the scale of the lepton flavor violating new physics that is a factor of $2.2$ weaker than the bound from meson decays. An exception to our conclusion arises from a specific combination of scalar and tensor SMEFT operators.

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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