Extra dimensions, orthopositronium decay, and stellar cooling

TL;DR

This paper explores how extra-dimensional models with warped metrics could cause photons to escape into extra dimensions, affecting astrophysical phenomena and providing bounds far beyond laboratory experiments.

Contribution

It introduces the idea that photons in these models can be metastable in plasma, linking extra-dimensional physics to astrophysical observations and constraints.

Findings

Photon escape into extra dimensions affects stellar cooling.

Astrophysical bounds surpass laboratory limits by orders of magnitude.

Implications for plasmon decay and supernova cooling rates.

Abstract

In a class of extra dimensional models with a warped metric and a single brane the photon can be localized on the brane by gravity only. An intriguing feature of these models is the possibility of the photon escaping into the extra dimensions. The search for this effect has motivated the present round of precision orthopositronium decay experiments. We point out that in this framework a photon in plasma should be metastable. We consider the astrophysical consequences of this observation, in particular, what it implies for the plasmon decay rate in globular cluster stars and for the core-collapse supernova cooling rate. The resulting bounds on the model parameter exceed the possible reach of orthopositronium experiments by many orders of magnitude.