Effects of Goldstone Bosons on Gamma-Ray Bursts

TL;DR

This paper investigates how Goldstone bosons produced in gamma-ray burst fireballs can serve as a probe for physics beyond the Standard Model, specifically constraining parameters of Weinberg's Higgs portal model.

Contribution

It demonstrates that gamma-ray bursts can be used to set competitive bounds on Higgs portal model parameters through Goldstone boson production and energy loss effects.

Findings

Goldstone bosons can be rapidly produced in GRB fireballs via electron-positron annihilation.

Goldstone bosons have a mean free path larger than the fireball size, leading to energy loss.

GRB bounds on Higgs portal parameters are competitive with laboratory constraints.

Abstract

Gamma-ray bursts (GRBs) are the most energetic explosion events in the universe. An amount of gravitational energy of the order of the rest-mass energy of the Sun is released from a small region, within seconds or longer. This should lead to the formation of a fireball of temperature in the MeV range, consisting of electrons/positrons, photons, and a small fraction of baryons. We exploit the potential of GRB fireballs for being a laboratory for testing particle physics beyond the Standard Model, where we find that Weinberg's Higgs portal model serves as a good candidate for this purpose. Due to the resonance effects, the Goldstone bosons can be rapidly produced by electron-positron annihilation process in the initial fireballs of the gamma-ray bursts. On the other hand, the mean free path of the Goldstone bosons is larger than the size of the GRB initial fireballs, so they are not coupled to the GRB's relativistic flow and can lead to significant energy loss. Using generic values for the GRB initial fireball energy, temperature, radius, expansion rate, and baryon number density, we find that the GRB bounds on the parameters of Weinberg's Higgs portal model are indeed competitive to current laboratory constraints.