Constraints on NJL four-fermion effective interactions from neutrinoless double beta decay
We study the contribution of a heavy right-handed Majorana neutrino to neutrinoless double beta decay ($0\nu\beta\beta$) via four-fermion effective interactions of Nambu-Jona-Lasinio (NJL) type. In this physical scenario, the sterile neutrino contributes to the nuclear transition through gauge, contact, and mixed interactions. Using the lower limit on the half-life of $0\nu\beta\beta$ from the KamLAND-Zen experiment, we then constrain the effective right-handed coupling between the sterile neutrino and the $W$ boson: $\mathcal{G}^{W}_{R}$. Eventually, we show that the obtained bounds are compatible with those found in the literature, which highlights the complementarity of this type of phenomenological study with high-energy experiments.