Nonstandard Neutrino Interactions in Supernovae

TL;DR

This paper investigates how nonstandard neutrino interactions can cause new flavor transformation phenomena in supernovae, affecting explosion dynamics and neutrino signals, even at strengths below current experimental limits.

Contribution

It identifies and characterizes new neutrino flavor transformation processes induced by NSI in supernovae, expanding understanding beyond standard oscillation physics.

Findings

Discovery of new transformation processes due to NSI

NSI can induce collective effects absent in standard physics

NSI can suppress the high-density MSW resonance

Abstract

Nonstandard interactions (NSI) of neutrinos with matter can significantly alter neutrino flavor evolution in supernovae with the potential to impact explosion dynamics, nucleosynthesis, and the neutrinos signal. In this paper, we explore, both numerically and analytically, the landscape of neutrino flavor transformation effects in supernovae due to NSI and find a new, heretofore unseen transformation processes can occur. These new transformations can take place with NSI strengths well below current experimental limits. Within a broad swath of NSI parameter space, we observe symmetric and standard matter-neutrino resonances for supernovae neutrinos, a transformation effect previously only seen in compact object merger scenarios; in another region of the parameter space we find the NSI can induce neutrino collective effects in scenarios where none would appear with only the standard case of neutrino oscillation physics; and in a third region the NSI can lead to the disappearance of the high density Mikheyev-Smirnov-Wolfenstein resonance. Using a variety of analytical tools, we are able to describe quantitatively the numerical results allowing us to partition the NSI parameter according to the transformation processes observed. Our results indicate nonstandard interactions of supernova neutrinos provide a sensitive probe of beyond the Standard Model physics complementary to present and future terrestrial experiments.