# Loop-enhanced rate of neutrinoless double beta decay

## TL;DR

This paper explores how loop corrections at the neutrino mass scale can significantly influence the amplitude of neutrinoless double beta decay, affecting its interpretation in neutrino physics.

## Contribution

It introduces the concept that loop effects at the relevant energy scale can enhance the decay rate, providing a new perspective on neutrino mass generation and decay analysis.

## Key findings

- Loop effects can modify the $0
uetaeta$ decay amplitude substantially.
- Off-shell neutrinos mediate the decay with virtuality around 100 MeV.
- Implications for interpreting future neutrinoless double beta decay experiments.

## Abstract

Neutrino masses can be generated radiatively. In such scenarios their masses are calculated by evaluating a self-energy diagram with vanishing external momentum, i.e. taking only the leading order term in a momentum expansion. The difference between the full self-energy and the mass is experimentally difficult to access, since one needs off-shell neurinos to observe them. However, massive Majorana neutrinos that mediate neutrinoless double beta decay ($0\nu\beta\beta$) are off-shell, with the virtuality of order 100 MeV. If the energy scale of the self-energy loop is of the order of this virtuality, the amplitude of double beta decay can be modified by the unsuppressed loop effect. This can have a drastic impact on the interpretation of future observations of the $0\nu\beta\beta$ decay.