Polarization mesurements of gamma ray bursts and axion like particles

Abstract

A polarized gamma ray emission spread over a sufficiently wide energy band from a strongly magnetized astrophysical object like gamma ray bursts (GRBs) offers an opportunity to test the hypothesis of axion like particles (ALPs). Based on evidences of polarized gamma ray emission detected in several gamma ray bursts we estimated the level of ALPs induced dichroism, which could take place in the magnetized fireball environment of a GRB. This allows to estimate the sensitivity of polarization measurements of GRBs to the ALP-photon coupling. This sensitivity $\gag\le 2.2\cdot 10^{-11} {\rm GeV^{-1}}$ calculated for the ALP mass $m_a=10^{-3}\mathrm{eV}$ and MeV energy spread of gamma ray emission is competitive with the sensitivity of CAST and becomes even stronger for lower ALPs masses.

Contribution to Proc. 4th Patras Workshop on Axions, WIMPs and WISPs (18-21 June 2008, DESY)

References in corpus (4)

• New PVLAS results and limits on magnetically induced optical rotation and ellipticity in vacuum
• Polarisation studies of the prompt gamma-ray emission from GRB 041219a using the Spectrometer aboard INTEGRAL
• POLAR, a compact detector for Gamma Ray Bursts photon polarization measurements
• Statistical Uncertainty in the Re-Analysis of Polarization in GRB021206