Sensitivity of Solar Neutrino Oscillations to Density Profile Perturbations

This undergraduate-led research project investigates how small perturbations in the solar electron density profile affect matter-induced neutrino flavor conversion, with the goal of gaining deeper insight into neutrino behavior and particle physics using computational tools. We model two-flavor neutrino oscillations in matter using a Schrödinger-like equation with a position-dependent effective potential arising from coherent forward scattering. Building on a baseline simulation of the standard exponential solar density profile, we explore how deviations—such as local bumps, dips, or gradient shifts—impact the survival probability of electron neutrinos, especially near the Mikheyev–Smirnov–Wolfenstein (MSW) resonance region.

To interpret these effects, we calculate the adiabaticity parameter and track its behavior near the resonance, where the system is most sensitive to changes in the density gradient. Perturbations are shown to shift the resonance location, alter adiabaticity, and produce measurable changes in survival probabilities in the intermediate energy range (5–10 MeV). Our results provide a framework for assessing whether small structural deviations in the Sun—or effects mimicking non-standard neutrino interactions—could be probed by future precision measurements. This project demonstrates how numerical methods can empower undergraduate researchers to explore questions at the intersection of astrophysics and particle physics.