论文标题
Lepton数字违反衰减的有效现场理论方法$ k^\ pm \rightarrowπ^\ mp l^{\ pm}_αl^{\ pm}_β$：长距离贡献
Effective field theory approach to lepton number violating decays $K^\pm\rightarrow π^\mp l^{\pm}_αl^{\pm}_β$: long-distance contribution
论文作者
论文摘要
这是我们最近的工作[1]的续集，在该续集中，我们计算了由于接触尺寸9（DIM-9）Quark-Lepton的有效相互作用而在高能量尺度引起的违反（LNV）$ K^\ pm $衰减。在这项工作中，我们调查了由中微子交换引起的衰减的长距离贡献。这些衰减可以探测涉及第二代费米子的相互作用，这些效率在核中度中性s $ $β$衰减中无法达到。从标准模型有效田间理论（SMEFT）到低能有效的田间理论（左）到手性扰动理论，我们的研究在有效场理论（EFT）的框架（EFT）的框架中完全表达。我们在每个有效的田间理论中都要在第一个非平凡的秩序上进行，并沿匹配条件和重新归一化组效应收集，并根据与SMEFT中与DIM-5和DIM-7运算符相关的Wilson系数表达衰减分支比。我们的结果通常是因为它不依赖于高度诱导SMEFT中有效相互作用的物理学的动态细节，并且它不吸引任何HADRONIC模型。我们发现，长距离贡献绝大多数在接触或短途距离上占主导地位。假设新的物理量表处于TEV附近，则分支比率被预测低于当前的实验上限。
This is a sequel to our recent work [1] in which we calculated the lepton number violating (LNV) $K^\pm$ decays due to contact dimension-9 (dim-9) quark-lepton effective interactions that are induced at a high energy scale. In this work we investigate the long-distance contribution to the decays arising from the exchange of a neutrino. These decays can probe LNV interactions involving the second generation of fermions that are not reachable in nuclear neutrinoless double-$β$ decays. Our study is completely formulated in the framework of effective field theories (EFTs), from the standard model effective field theory (SMEFT) through the low energy effective field theory (LEFT) to chiral perturbation theory. We work to the first nontrivial orders in each effective field theory, collect along the way the matching conditions and renormalization group effects, and express the decay branching ratios in terms of the Wilson coefficients associated with the dim-5 and dim-7 operators in SMEFT. Our result is general in that it does not depend on dynamical details of physics at a high scale that induce the effective interactions in SMEFT and in that it does not appeal to any hadronic models. We find that the long-distance contribution overwhelmingly dominates over the contact or short-distance one. Assuming the new physics scale to be around a TeV, the branching ratios are predicted to be below the current experimental upper bounds by several orders of magnitude.
