MEDEX'19

More than Exotic Neutrinoless Double Beta Decay with Majoron-like Emission

May 28, 2019, 11:00 AM

30m

Balling Hall (ground floor) (The Czech National Library of Technology)

Oral Presentation Session (Chair: F. Simkovic)

Speaker

Dr Frank Deppisch (UCL)

Description

I present a novel mode of neutrinoless double beta decay with emission of a light Majoron-like scalar particle $\varphi$. We assume it couples via an effective seven-dimensional operator with a $(V+A)$ lepton current and $(V\pm A)$ quark currents leading to a long-range contribution that is unsuppressed by the light neutrino mass. Calculating the total double beta decay rate and determine the fully differential shape for this mode, we find that future double beta decay searches are sensitive to scales of the order ${\mathrm{\Lambda }}_{NP}\approx 1$ TeV for the effective operator and a light scalar $m_{\varphi }<0.2$ MeV, based on ordinary double beta decay Majoron searches. The angular and energy distributions can deviate considerably from that of two-neutrino double beta decay, which is the main background. I discuss possible ultraviolet completions where such an effective operator can emerge.

Presentation materials

Slides

FrankDeppisch_MEDEX19.pdf