Starting from a general effective Lagrangian for lepton flavor violation (LFV) in quark-lepton transitions, we derive constraints on the effective coefficients from the high-mass tails of the dilepton processes \(pp \rightarrow \ell _k \ell _l\) (with \(k\ne l\)). The current (projected) limits derived in this paper from LHC data with \(36~\mathrm {fb}^{-1}\) (\(3~\mathrm {ab}^{-1}\)) can be applied to generic new physics scenarios, including the ones with scalar, vector and tensor effective operators. For purely left-handed operators, we explicitly compare these LHC constraints with the ones derived from flavor-physics observables, illustrating the complementarity of these different probes. While flavor physics is typically more constraining for quark-flavor violating operators, we find that LHC provides the most stringent limits on several flavor-conserving ones. Furthermore, we show that dilepton tails offer the best probes for charm-quark transitions at current luminosities and that they provide competitive limits for tauonic \(b\rightarrow d\) transitions at the high-luminosity LHC phase. As a by-product, we also provide general numerical expressions for several low-energy LFV processes, such as the semi-leptonic decays \(K\rightarrow \pi \ell ^{\pm }_k \ell ^{{\mp }}_l\), \(B\rightarrow \pi \ell ^{\pm }_k \ell ^{{\mp }}_l\) and \(B\rightarrow K^{(*)} \ell ^{\pm }_k \ell ^{{\mp }}_l\).A preprint version of the article is available at ArXiv.

中文翻译：

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大型强子对撞机中的轻子味道违规和双轻子尾部。

从夸克-轻子跃迁中轻子味道破坏（LFV）的一般有效拉格朗日算子开始，我们从双轻子过程的高质量尾部推导了对有效系数的约束\(pp \rightarrow \ell _k \ell _l\) (与\(k\ne l\)）。本文从 LHC 数据得出的当前（预计）极限为\(36~\mathrm {fb}^{-1}\) ( \(3~\mathrm {ab}^{-1}\) )应用于通用的新物理场景，包括具有标量、向量和张量有效算子的场景。对于纯粹的左手操作员，我们明确地将这些 LHC 约束与从味道物理可观察量导出的约束进行比较，说明这些不同探针的互补性。虽然风味物理学通常对夸克风味违规算子的限制更大，但我们发现大型强子对撞机对几种风味保持算子提供了最严格的限制。此外，我们表明，双轻子尾为当前光度下的粲夸克跃迁提供了最佳探针，并且它们为高光度 LHC 阶段的tauonic \(b\rightarrow d\)跃迁提供了竞争限制。作为副产品，我们还提供了几种低能 LFV 过程的通用数值表达式，例如半轻子衰变\(K\rightarrow \pi \ell ^{\pm }_k \ell ^{{\mp } }_l\)、\(B\rightarrow \pi \ell ^{\pm }_k \ell ^{{\mp }}_l\)和\(B\rightarrow K^{(*)} \ell ^{\下午 }_k \ell ^{{\mp }}_l\)。ArXiv 提供了该文章的预印本。