Heavy Ion Charge Exchange Reactions as Probes for Beta–Decay

Horst Lenske,G De Angelis,L Corradi

doi:10.1051/epjconf/201922301031

Abstract

Peripheral heavy ion single and double charge reactions are described by fully quantum mechanical distorted wave methods. A special class of nuclear double charge exchange (DCE) reactions proceeding as a one-step reaction through a two-body process are shown to proceed by nuclear matrix elements of a diagrammatic structure as found also in 0ν2ß decay. These hadronic Majorana-type DCE reactions (MDCE) have to be distinguished from second order DCE reactions, given by double single charge exchange (DSCE) processes, resembling 2ν2ß decay. The theoretical concepts of MDCE are discussed. First results show that ion-ion DCE reactions are the ideal testing grounds for investigations of rare second order nuclear processes, giving insight into nuclear in-medium two-body correlation.

Highlights

There is broad consensus that 0ν2β decay will be a highly promising gateway to physics beyond the standard model of elementary particle physics
While single charge exchange (SCE) reactions with light and heavy ions have been studied intensively, see e.g. [9, 10], close to nothing is known about double charge exchange reactions
Second order quantal processes like heavy ion double charge exchange reactions are of genuine reaction theoretical interest

Summary

Introduction

There is broad consensus that 0ν2β decay will be a highly promising gateway to physics beyond the standard model of elementary particle physics Once observed, it will give direct evidence on the Majorana-nature of neutrinos with far reaching implications for neutrino masses, neutrinomatter interactions and flavour mixing up to the question of the matter-antimatter asymmetry in the universe [1,2,3,4,5]. It will give direct evidence on the Majorana-nature of neutrinos with far reaching implications for neutrino masses, neutrinomatter interactions and flavour mixing up to the question of the matter-antimatter asymmetry in the universe [1,2,3,4,5] Such a signal has to be distinguished from the twoneutrino beta-decay (2ν2β) [6, 7] which is allowed in the standard model.

Single Charge Exchange and Double Single Charge Exchange Reactions

Majorana Double Charge Exchange Reactions

Heavy Ion DCE Reactions and Data

Outlook