Unparticle constraints from SN1987A

TL;DR

This paper investigates how hypothetical unparticle sectors could affect supernova physics, especially SN1987A, and derives constraints on their interactions based on observed neutrino emissions.

Contribution

It provides new constraints on unparticle interactions from supernova observations, especially considering models with broken scale invariance due to the Higgs vacuum.

Findings

Unparticle emission would shorten SN1987A neutrino burst if interactions were strong.

Constraints show unparticle interactions are very weak, unlikely to produce collider signatures.

Models with broken scale invariance suppress supernova emission, relaxing constraints.

Abstract

The existence of an unparticle sector, weakly coupled to the standard model, would have a profound impact on supernova (SN) physics. Emission of energy into the unparticle sector from the core of SN1987A would have significantly shortened the observed neutrino burst. The unparticle interaction with nucleons, neutrinos, electrons and muons is constrained to be so weak that it is unlikely to provide any missing-energy signature at colliders. One important exception are models where scale invariance in the hidden sector is broken by the Higgs vacuum expectation value. In this case the SN emission is suppressed by threshold effects.