Scalar NSI: A unique tool for constraining absolute neutrino masses via $\nu$-oscillations

TL;DR

This paper proposes a novel method using scalar non-standard interactions (SNSI) in neutrino oscillations to directly constrain the absolute neutrino masses, which is not possible with standard oscillation analysis alone.

Contribution

It introduces the first constraints on absolute neutrino masses via SNSI effects in neutrino oscillations, especially using DUNE data.

Findings

SNSI can induce bounds on the lightest neutrino mass.

Constraints are effective for normal hierarchy regardless of $ heta_{23}$ octant.

SNSI provides a new avenue for neutrino mass measurement in long-baseline experiments.

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. We have explored the constraints on the lightest neutrino mass with different choices of $\delta_{CP}$ and $\theta_{23}$ for both neutrino mass hierarchies. We show that a bound on the neutrino mass can be induced in the presence of SNSI at DUNE. We find that the lightest neutrino mass can be constrained with $\eta_{\tau\tau}$ for normal mass hierarchy irrespective of the octant of $\theta_{23}$ and the value of the CP phase $\delta_{CP}$. This study suggests that SNSI can serve as an interesting avenue to constrain the absolute neutrino masses in long-baseline neutrino experiments via neutrino oscillations.