Scalar NSI: a unique tool for constraining absolute neutrino masses via neutrino oscillations

Abstract

In the standard interaction scenario, a direct measurement of absolute neutrino masses via neutrino oscillations is not feasible, as the oscillations depend only on the mass-squared differences. However,scalar non-standard interactions (SNSI) can introduce sub-dominant terms in the neutrino oscillation Hamiltonian that can directly affect the neutrino mass matrix, thereby making SNSI a unique tool for neutrino mass measurements. In this work, for the first time, we constrain the absolute masses of neutrinos by probing SNSI in a neutrino oscillation experiment. We show that a bound on the neutrino mass can be induced in the presence of SNSI at DUNE. We note that the constraints on the neutrino mass are much better for \(\eta _{\mu \mu }\) and \(\eta _{\tau \tau }\) as compared to \(\eta _{ee}\) for both NO and IO scenarios. We have also explored the constraints on the neutrino mass for different choices of \(\delta _{CP}\) and \(\theta _{23}\) for both neutrino mass orderings. This study shows that SNSI can serve as an interesting avenue to constrain the absolute neutrino masses in long-baseline neutrino experiments via neutrino oscillations.