Angelescu Andrei, Faroughy Darius A, Sumensari Olcyr
Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588 USA.
Physik-Institut, Universität Zürich, 8057 Zürich, Switzerland.
Eur Phys J C Part Fields. 2020;80(7):641. doi: 10.1140/epjc/s10052-020-8210-5. Epub 2020 Jul 19.
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 (with ). The current (projected) limits derived in this paper from LHC data with ( ) 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 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 , and .
从描述夸克 - 轻子跃迁中轻子味违反（LFV）的一般有效拉格朗日量出发，我们从双轻子过程（其中）的高质量尾部推导出对有效系数的限制。本文利用（）的大型强子对撞机（LHC）数据得出的当前（预计）限制可应用于一般的新物理情景，包括具有标量、矢量和张量有效算符的情景。对于纯左手算符，我们明确地将这些LHC限制与从味物理可观测量得出的限制进行比较，展示了这些不同探测方法的互补性。虽然味物理通常对违反夸克味的算符限制更强，但我们发现LHC对几个味守恒的算符提供了最严格的限制。此外，我们表明双轻子尾部在当前亮度下为粲夸克跃迁提供了最佳探测方法，并且在高亮度LHC阶段为陶轻子跃迁提供了具有竞争力的限制。作为副产品，我们还给出了几个低能LFV过程的一般数值表达式，如半轻子衰变、和。
