Probing neutrino-night-quark effective scalar interactions from neutrino masses

TL;DR

This paper investigates how neutrino masses can be used to constrain effective scalar interactions between neutrinos and light quarks, emphasizing the significance of both perturbative and nonperturbative contributions.

Contribution

It introduces a comprehensive analysis including quark condensate effects in neutrino mass constraints on scalar interactions, which were previously overlooked.

Findings

Neutrino masses constrain scalar couplings more tightly than other observables.

Both quark loop and condensate contributions are comparable for u and d quarks.

Electron neutrino mass measurements provide the strongest bounds on these interactions.

Abstract

In this work, we use neutrino masses as a probe of the neutrino-light-quark effective scalar interactions. It is found that neutrinos can acquire masses not only from the usual light quark loop corrections but also from the light quark condensates. The latter contribution has been overlooked in the literature. We show that both contributions are comparable for operators involving $u$ and $d$ quarks, while quark loop corrections dominate for operators involving the $s$ quark. Using the low-energy effective field theory extended with light right-handed neutrinos and matching to chiral perturbation theory, we systematically analyze these contributions, deriving constraints on the corresponding Wilson coefficients from neutrino mass bounds, coherent elastic neutrino-nucleus scattering, and light pseudoscalar meson invisible decays. Our analysis shows that electron neutrino mass measurements provide the most stringent constraints on these scalar couplings, significantly improving upon limits from other observables. The results highlight the importance of including both perturbative and nonperturbative contributions in complete phenomenological analyses of neutrino mass generation mechanisms.