Impact of a light stabilized radion in supernovae cooling

TL;DR

This paper investigates how a stabilized radion in the Randall-Sundrum model affects supernova cooling, deriving bounds on the radion's vacuum expectation value based on SN1987A energy loss constraints.

Contribution

It provides the first bounds on the radion vev in the Randall-Sundrum model from supernova cooling data, considering various radion masses.

Findings

Lower bounds on radion vev: 9.0 TeV, 2.2 TeV, 0.9 TeV for radion masses 5, 20, 50 GeV.

Radion production in supernovae can significantly contribute to energy loss.

Constraints are consistent with existing collider bounds.

Abstract

In the Randall-Sundrum model where the Standard Model fields are confined to the TeV brane located at the orbifold point $\theta = \pi$ and the gravity peaks at the Planck brane located at $\theta = 0$, the stabilized modulus (radion) field is required to stabilize the size of the fifth spatial dimension. It can be produced copiously inside the supernova core due to nucleon-nucleon bremstrahlung, electron-positron and plasmon-plasmon annihilations, which then subsequently decays to neutrino-antineutrino pair and take away the energy released in SN1987A explosion. Assuming that the supernovae cooling rate $\dot{\varepsilon} \le 7.288\times 10^{-27} \rm{GeV}$, we find the lower bound on the radion vev $\vphi \sim 9.0$ TeV, 2.2 TeV and 0.9 TeV corresponding to the radion mass $m_\phi = 5$ GeV, 20 GeV and 50 GeV, respectively.