Exploring nonstandard quark interactions through solar neutrino studies

TL;DR

This paper explores how non-standard neutrino interactions mediated by a new Z' boson could influence solar neutrino oscillations, potentially fitting experimental data better than the standard model.

Contribution

It introduces a specific NSI model with a Z' boson affecting neutrino interactions, and constrains its parameters using solar neutrino data, showing compatibility and potential improvements over the standard model.

Findings

NSI model fits solar neutrino data with $$ between -0.7 and 0.002

Best fit occurs at $ = -0.2$ with $$ = 2.96

Including Darwin data narrows $$ range to -0.5 to -0.002

Abstract

We investigate the effects of a Non-Standard Interaction (NSI) extension of the standard model of particle physics on solar neutrino flavour oscillations. This NSI model introduces a $U_{Z^\prime}(1)$ gauge symmetry through a $Z^\prime$ boson that mixes with the photon, creating a neutral current between active neutrinos and matter fields via a unique coupling to up and down quarks. The interaction is defined by a single parameter, $\zeta_o$, which is related to the $Z^\prime$ boson's mass $m_{Z^\prime}$ and coupling constant $g_{Z^\prime}$. Notably, this model relaxes the bounds on Coherent Elastic Neutrino-Nucleus Scattering experiments and fits the experimental values of the anomalous magnetic dipole moment of the muon. In this study, we use solar neutrino measurements and an up-to-date standard solar model to evaluate the neutrino flavour oscillations and assess the constraints on $\zeta_o$. Our study indicates that the NSI model aligns with the current solar neutrino data when $\zeta_o$ is between $-0.7$ and $0.002$. These models have $\chi^2_{\nu}$ values equal to or better than the standard neutrino flavor oscillation model, which stands at a $\chi^2_{\nu}$ of 3.12. The best NSI model comes with a $\zeta_o$ value of -0.2 and a $\chi^2_{\nu}$ of 2.96. Including extra data from the Darwin experiment in our analysis refines the range of $\zeta_o$ values from $-0.7$ to $0.002$, down to $-0.5$ to $-0.002$. These results hint at the possible existence of novel interactions, given that NSI models achieve a comparable or superior fit to the solar neutrino data when contrasted with the prevailing standard model of neutrino flavour oscillation.