The effects of triplet Higgs bosons in long baseline neutrino experiments

TL;DR

This paper explores how triplet Higgs bosons in the Type-II seesaw model could induce nonstandard neutrino interactions detectable in long baseline experiments like DUNE, and assesses bounds on model parameters from experimental data.

Contribution

It provides a detailed analysis of the potential to probe triplet Higgs effects in neutrino experiments and derives bounds on model parameters based on experimental sensitivities.

Findings

DUNE can set upper bounds on nonstandard interaction parameters.

Derived bounds depend on the lightest neutrino mass and triplet scalar mass.

Compared effects with charged lepton flavor violation constraints.

Abstract

The triplet scalars $(\Delta=\Delta^{++},\Delta^{+},\Delta^{0})$, utilized in the so-called Type-II seesaw model to explain the lightness of neutrinos, would generate nonstandard interactions (NSI) for neutrino propagating in matter. We investigate the prospects to probe these interactions in long baseline neutrino oscillation experiments. We analyze the upper bounds that the proposed DUNE experiment might set on the nonstandard parameters and numerically derive upper bounds, as function of the lightest neutrino mass, on the ratio the mass $M_\Delta$ of the triplet scalars and strength $|\lambda_\phi|$ of the coupling $\phi\phi\Delta$ of the triplet $\Delta$ and conventional Higgs doublet $\phi$ . We also discuss the possible misinterpretation of these effects as effects arising from a nonunitarity of the neutrino mixing matrix and compare the results with the bounds that arise from the charged lepton flavor violating processes.