Probing Lepton Flavor Violation at Linear Electron-Positron Colliders

2025/05/16 by Wolfgang Altmannshofer, Pankaj Munbodh, Altmannshofer, Wolfgang +1 · 3 citations
Computer Science · Physics and Astronomy · #Computational Physics and Python Applications #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Neutrino Physics Research #Particle physics theoretical and experimental studies

paper · pdf · doi:10.48550/arxiv.2505.11653

openalex publication_date 2025/05/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

The production of τμ pairs in electron-positron collisions offers a powerful probe of lepton flavor violation. In this work, we calculate the e⁺ e^- → τμ cross section within the framework of the Standard Model Effective Field Theory, allowing for arbitrary e⁺e^- beam polarizations. We then estimate the sensitivities of proposed future linear colliders, ILC and CLIC, to effective lepton flavor-violating interactions. The high center-of-mass energies achievable at these machines provide particularly strong sensitivity to four-fermion operators. Furthermore, the polarization of the e⁺e^- beams enables novel tests of the chirality structure of these interactions. We find that our projected sensitivities not only complement but in certain scenarios surpass those achievable with low-energy tau decay measurements at Belle~II.

Citations

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• Physics and Detectors at CLIC: CLIC Conceptual Design Report
• Dimension-six terms in the Standard Model Lagrangian
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• Coherent Exclusive Exponentiation for Precision Monte Carlo Calculations of Fermion Pair Production / Precision Predictions for (Un)stable W+W- Pairs

Cited by

• Flavor physics at high-energy muon colliders
• Lepton flavor violating top quark FCNC at the μTRISTAN
• Investigating the leptonic couplings of doubly charged scalars at the muon collider

Related

• Exploring Optimal Sensitivity of Lepton Flavor Violating Effective Couplings at the e⁺e^- Colliders
• Probing Lepton Flavor Violation at Circular Electron-Positron Colliders
• Lepton flavor violation via four-Fermi contact interactions at the International Linear Collider
• Lepton Flavor Violation at FCC-ee and CEPC
• Searching for the LFV γγeμ interaction at future e^- e⁺ colliders