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arXiv · 2603.04171

Nuclear $\mu-e$ conversion via Lorentz and CPT violation

William P. McNulty
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Abstract

One of the three common experimental channels searching for charged lepton flavor violation (CLFV) via $\mu-e$ conversion involves first capturing the muon on a nuclear target. This channel provides a unique opportunity to constrain four-point quark-lepton operators that may contribute to CLFV, in addition to the electromagnetic operators that can also be accessed in the other channels. We investigate the leading Lorentz- and CPT-violating contributions for nuclear $\mu-e$ conversion experiments within the Standard-Model Extension and obtain the first bounds on the relevant quark-lepton operators using the results of the SINDRUM II experiment; we also consider possibilities for improved constraints from upcoming experiments.

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William P. McNulty. 2026-03-04. Nuclear $\mu-e$ conversion via Lorentz and CPT violation. https://arxiv.org/abs/2603.04171

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