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arXiv · 2308.03356

Relativistic model-free prediction for neutrinoless double beta decay at leading order

Y. L. Yang·P. W. Zhao
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Abstract

Starting from a manifestly Lorentz-invariant chiral Lagrangian, we present a model-free prediction for the transition amplitude of the process $nn\rightarrow pp e^-e^-$ induced by light Majorana neutrinos, which is a key process of the neutrinoless double beta decay ($0\nu\beta\beta$) in heavy nuclei employed in large-scale searches. Contrary to the nonrelativistic case, we show that the transition amplitude can be renormalized at leading order without any uncertain contact operators. The predicted amplitude defines a stringent benchmark for the previous estimation with model-dependent inputs, and greatly reduces the uncertainty of $0\nu\beta\beta$ transition operator in the calculations of nuclear matrix elements. Generalizations of the present framework could also help to address the uncertainties in $0\nu\beta\beta$ decay induced by other mechanisms. In addition, the present work motivates a relativistic {\it ab initio} calculation of $0\nu\beta\beta$ decay in light and medium-mass nuclei.

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Y. L. Yang, P. W. Zhao. 2023-08-07. Relativistic model-free prediction for neutrinoless double beta decay at leading order. https://doi.org/10.1016/j.physletb.2024.138782

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