Constraints on Astro-unparticle Physics from SN 1987A

TL;DR

This paper uses SN 1987A observations to set constraints on unparticle interactions with standard model particles, analyzing energy loss mechanisms and deriving bounds on coupling constants for various unparticle types.

Contribution

It provides the first detailed constraints on unparticle couplings from supernova data, considering multiple unparticle types and emission processes.

Findings

Stringent bounds on pseudo scalar and pseudo-vector couplings: |λ₀,₁^P| ≤ 4×10⁻¹¹

Limit on tensor interaction coupling: |λ^T| ≤ 6×10⁻⁶

Constraints derived for unparticle dimension d_U=1 at Λ_U = m_Z

Abstract

SN 1987A observations have been used to place constraints on the interactions between standard model particles and unparticles. In this study we calculate the energy loss from the supernovae core through scalar, pseudo scalar, vector, pseudo vector unparticle emission from nuclear bremsstrahlung for degenerate nuclear matter interacting through one pion exchange. In order to examine the constraints on $d_{\cal U}=1$ we considered the emission of scalar, pseudo scalar, vector, pseudo vector and tensor through the pair annihilation process $e^+e^-\to {\cal U} \gamma $. In addition we have re-examined other pair annihilation processes. The most stringent bounds on the dimensionless coupling constants for $d_{\cal U} =1$ and $\Lambda_{\cal U}= m_Z$ are obtained from nuclear bremsstrahlung process for the pseudo scalar and pseudo-vector couplings $\bigl|\lambda^{\cal P}_{0,1}\bigr|\leq 4\times 10^{-11}$ and for tensor interaction, the best limit on dimensionless coupling is obtained from $e^+ e^-\to {\cal U} \gamma$ and we get $\bigl|\lambda^{\cal T}\bigr| \leq 6\times 10^{-6}$.