Probing a 146 GeV cLFV scalar using the LHC and low-energy experiments
Abstract
The CMS Collaboration reported a local excess at 146 GeV in the search for the lepton-flavor-violating decay of the Higgs boson and additional Higgs bosons in the eμ final state at √s= 13 TeV. If confirmed, this would constitute a major piece of evidence of charged lepton flavor violation (cLFV). We investigate the compatibility of the claimed signal with the full suite of existing low-energy cLFV constraints in a bottom-up effective description: a single real scalar of mass 146 GeV coupled to gluons and to all charged-lepton bilinears, with seven free parameters that simultaneously control the LHC production cross section, every di-lepton decay channel, and every low-energy cLFV observable. A Bayesian MCMC analysis against μ−e conversion, muonium-antimuonium oscillation, three-lepton and radiative LFV decays, semileptonic τ LFV decays, and LHC di-lepton searches yields a preferred mode with peaked value Yeμ ∼ 10−4.09, already cut into by the current μ−e conversion limits. The projected sensitivities of Mu2e, COMET, Mu3e, MACE, MEG~II, Belle~II, STCF, and the HL-LHC directly probe the region of coupling space selected by the CMS excess, so the complementarity between high-energy and low-energy cLFV probes will either corroborate or decisively exclude the scalar interpretation of the anomaly within the next decade.
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BibTeX
@misc{gao2026probing,
title = {{Probing a 146 GeV cLFV scalar using the LHC and low-energy experiments}},
author = {Christina Gao and Lingfeng Li and Z. J. Xiong},
howpublished = {arXiv},
year = {2026},
month = aug,
doi = {10.48550/arxiv.2607.03249},
eprint = {2607.03249},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.03249},
}
RIS
TY - UNPB
TI - Probing a 146 GeV cLFV scalar using the LHC and low-energy experiments
AU - Christina Gao
AU - Lingfeng Li
AU - Z. J. Xiong
PY - 2026
DA - 2026/08/30
PB - arXiv
DO - 10.48550/arxiv.2607.03249
UR - https://arxiv.org/abs/2607.03249
AB - The CMS Collaboration reported a local excess at 146 GeV in the search for the lepton-flavor-violating decay of the Higgs boson and additional Higgs bosons in the eμ final state at √s= 13 TeV. If confirmed, this would constitute a major piece of evidence of charged lepton flavor violation (cLFV). We investigate the compatibility of the claimed signal with the full suite of existing low-energy cLFV constraints in a bottom-up effective description: a single real scalar of mass 146 GeV coupled to gluons and to all charged-lepton bilinears, with seven free parameters that simultaneously control the LHC production cross section, every di-lepton decay channel, and every low-energy cLFV observable. A Bayesian MCMC analysis against μ−e conversion, muonium-antimuonium oscillation, three-lepton and radiative LFV decays, semileptonic τ LFV decays, and LHC di-lepton searches yields a preferred mode with peaked value Y_eμ ∼ 10^−4.09, already cut into by the current μ−e conversion limits. The projected sensitivities of Mu2e, COMET, Mu3e, MACE, MEG~II, Belle~II, STCF, and the HL-LHC directly probe the region of coupling space selected by the CMS excess, so the complementarity between high-energy and low-energy cLFV probes will either corroborate or decisively exclude the scalar interpretation of the anomaly within the next decade.
ER -