Probing $\mu e \gamma \gamma$ contact interactions with $\mu \to e$ conversion

Sacha Davidson (1) , Yoshitaka Kuno , Yuichi Uesaka , Masato Yamanaka

1 LUPM - Laboratoire Univers et Particules de Montpellier

Contact interactions of a muon, an electron and two photons can contribute to the decay μ→eγγ, but also to the conversion of a muon into an electron in the electric field of a nucleus. We calculate the μ→e conversion rate, and show that for the coefficients of operators involving the combination FF∝|E→|2 (as opposed to FF˜∝E→·B→), the current bound on μ→e conversion is more sensitive than the bound on μ→eγγ.

Mots clés: Beyond the standard model; contact interaction; operator: dimension: 6; lepton: flavor: violation; neutral current: flavor changing; quantum electrodynamics; two-photon; nucleus: electric field; sensitivity; numerical calculations; new physics

Domaines: Physique des Hautes Energies - Phénoménologie [hep-ph]

Sacha Davidson, Yoshitaka Kuno, Yuichi Uesaka, Masato Yamanaka. Probing $\mu e \gamma \gamma$ contact interactions with $\mu \to e$ conversion. Physical Review D, 2020, 102 (11), pp.115043. ⟨10.1103/PhysRevD.102.115043⟩. ⟨hal-02914464⟩