Exotic neutrinoless double beta decay with Majoron-like emission

Abstract

We discuss a novel mode of neutrinoless double-β decay with emission of a light Majoron-like scalar particle ϕ which couples via an effective 7-dimensional operator with a (V + A) lepton current and (V ± A) quark currents leading to a long-range contribution. Future double-β decay searches are sensitive to scales of the order ΛNP ≈ 1 TeV for the effective operator. In a left-right symmetric model, this mode can probe right-handed W boson masses up to 25 TeV.We discuss a novel mode of neutrinoless double-β decay with emission of a light Majoron-like scalar particle ϕ which couples via an effective 7-dimensional operator with a (V + A) lepton current and (V ± A) quark currents leading to a long-range contribution. Future double-β decay searches are sensitive to scales of the order ΛNP ≈ 1 TeV for the effective operator. In a left-right symmetric model, this mode can probe right-handed W boson masses up to 25 TeV.