Neutrinoless quadruple beta decay
1 Max-Planck- Institut für Kernphysik - Saupfercheckweg 1, 69117 Heidelberg, Germany, EU
Received: 3 July 2013
Accepted: 25 July 2013
We point out that lepton number violation is possible even if neutrinos are Dirac particles. We illustrate this by constructing a simple model that allows for lepton number violation by four units only. As a consequence, neutrinoless double beta decay is forbidden, but neutrinoless quadruple beta decay is possible: . We identify three candidate isotopes for this decay, the most promising one being 150Nd due to its high -value of . Analogous processes, such as neutrinoless quadruple electron capture, are also possible. The expected lifetimes are extremely long, and experimental searches are challenging.
PACS: 23.40.-s – β decay; double β decay; electron and muon capture / 14.60.St – Non-standard-model neutrinos, right-handed neutrinos, etc. / 11.30.Fs – Global symmetries (e.g., baryon number, lepton number)
© EPLA, 2013