Left-Right Symmetry and Leading Contributions to Neutrinoless Double Beta Decay
We study the impact of the mixing (LR mixing) between the standard model W boson and its hypothetical, heavier right-handed parter W_R on the neutrinoless double beta decay (0νββ decay) rate. Our study is done in the minimal left-right symmetric model assuming a type-II dominance scenario with charge conjugation as the left-right symmetry. We then show that the 0νββ decay rate may be dominated by the contribution proportional to this LR mixing, which at the hadronic level induces the leading-order contribution to the interaction between two pions and two charged leptons. The resulting long-range pion exchange contribution can significantly enhance the decay rate compared to previously considered short-range contributions. Finally, we find that even if future cosmological experiments rule out the inverted hierarchy for neutrino masses, there are still good prospects for a positive signal in the next generation of 0νββ decay experiments.
Additional Information© 2021 Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3. Received 21 October 2020; accepted 8 March 2021; published 16 April 2021. G. L. and J. C. V. would like to thank Jordy de Vries for many valuable discussions. G. L. thanks Wouter Dekens and Jordy de Vries for fruitful discussions on the half-life calculations regarding Refs. [50,77], and Xiao-Dong Ma and Jiang-Hao Yu for the discussions on RGEs. J. C. V. was supported in part under the U.S. Department of Energy Contract No. DE-SC0015376. G. L. and M. R.-M. were supported in part under U.S. Department of Energy Contract No. DE-SC0011095. M. R.-M. was also supported in part under National Science Foundation of China Grant No. 19Z103010239.
Published - PhysRevLett.126.151801.pdf
Accepted Version - 2009.01257.pdf