2020/09/02 by Gang Li, Michael Ramsey-Musolf, Juan Carlos Vasquez · 1 citation
Physics and Astronomy · #hep-ph #nucl-ex #nucl-th
paper · pdf · doi:10.1103/physrevlett.126.151801
published as Phys. Rev. Lett. 126, 151801 (2021) · 6 pages, 3 figures
arxiv created 2020/09/02 · arxiv updated 2021/04/21
We study the impact of the mixing (LR mixing) between the standard model W boson and its hypothetical, heavier right-handed parter WR on the neutrinoless double beta decay (0νββ-decay) rate. Our study is done in the minimal left-right symmetric model assuming 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.