论文标题
限制$ q^2 l^2 $运算符，从$π^0 \rightarrowμE$ $
Restricting $q^2 l^2$ operators from $π^0 \rightarrow μe$
论文作者
论文摘要
在本文中，我们考虑了低能量有效理论（左）的$ q^2l^2 $类型的半衰弱的Lepton风味操作员（左）。在手性量表上，我们将这些操作员与手性扰动理论（$χ$ pt）相匹配，并从该过程$π^0 \rightArrowμ^+ \，\，\，e^ - $放置约束。这些界限证明取决于操作员的手性质。与矢量运算符相比，标量运算符的限制更大。然后，我们将从$μ\与核中的E $转换的限制进行比较，并表明标量运算符的限制在相应限制的数量级内，从$μ\ \ e $转换在Ti中。另一方面，矢量运营商的限制要弱得多。最后，我们将左操作员进化为使用RGE进行W-boson质量尺度，并将其与标准模型有效场理论（SMEFT）运算符相匹配。然后，我们在Leptoquark模型的参数空间上得出了约束，这些模型可以在树级生成这些SMEFT运算符。
In this paper we consider semileptonic lepton flavor violating operators of the type $q^2l^2$ in low energy effective theory (LEFT). At the chiral scale, we match these operators to chiral perturbation theory ($χ$PT) and place constraints from the process $π^0\rightarrow μ^+ \,\, e^-$. These bounds are shown to depend on the chiral nature of the operators. The scalar operators are significantly more constrained compared to the vector operators. We then compare the limits from $μ\to e$ conversion in Nuclei and show that the limits on scalar operators are within an order of magnitude of the corresponding limits from $μ\to e$ conversion in Ti. On the other hand, the limits on vector operators are however much weaker. Towards the end, we evolve the LEFT operators to W-boson mass scale using RGE, and match them to the Standard Model effective field theory (SMEFT) operators. We, then, derive the constraints on the parameter space of Leptoquark models that could generate these SMEFT operators at tree level.
