An Effective Method to Accurately Calculate the Phase Space Factors forβ-β-Decay

Andrei Neacsu,Mihai Horoi

doi:10.1155/2016/7486712

Abstract

Accurate calculations of the electron phase space factors are necessary for reliable predictions of double-beta decay rates and for the analysis of the associated electron angular and energy distributions. We present an effective method to calculate these phase space factors that takes into account the distorted Coulomb field of the daughter nucleus, yet it allows one to easily calculate the phase space factors with good accuracy relative to the most exact methods available in the recent literature.

Highlights

Double-beta decay processes are of considerable importance for the study of neutrinos
Should the lepton number conservation be violated, theories beyond the standard model (BSM) predict that the ββ decay transition could occur without antineutrinos in the final state, called neutrinoless double-beta (0]ββ), and this implies that the neutrino is a Majorana fermion [2]
We find that the smallest maximum deviations from the data can be obtained using an optimal “screening factor” Sf = 94.5

Summary

Introduction

Double-beta decay (ββ) processes are of considerable importance for the study of neutrinos. The ββ decay with two associated electron antineutrinos in the final state conserves the lepton number and is permitted within the standard model (SM). This process, called two-neutrino double-beta decay (2]ββ), has been experimentally observed for several isotopes with transitions to both ground states and excited states of the daughter nuclei [1]. Should the lepton number conservation be violated, theories beyond the standard model (BSM) predict that the ββ decay transition could occur without antineutrinos in the final state, called neutrinoless double-beta (0]ββ), and this implies that the neutrino is a Majorana fermion [2]. More complex, mechanisms include contributions from right-handed currents [6, 7] and mechanisms involving supersymmetry [5, 8]

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Results

Conclusion