Constraints on Axionlike Particles from gamma ray observations

As a generalization of the axion, the axionlike particle (ALP) is a pseudo-Goldstone boson predicted in several extensions of the Standard Model. An ALP could oscillate with a photon in an external electric or magnetic field, providing a promising way to detect it. There are large-scale coherent magnetic fields in galaxies and galaxy clusters, with coherent lengths as long as tens of kpc. These regions are ideal targets to search for ALPs. We searched for ALP signals in the γ-ray from several γ-ray sources, such as active galactic nucleus (AGN), supernova remnants and pulsar wind nebula. Although no significant evidence for the presence of ALP-photon oscillation was obtained, we got some strong constraints on the parameters of ALPs. With the higher energy resolution experiments, such as Dark Matter Particle Explorer (DAMPE) and Cherenkov Telescope Array (CTA), significant progresses on revealing the ALP properties are expected in the next decade.

Speaker: 
Cun Zhang
Place: 
DoA, Rm 2907
Time: 
Monday, December 2, 2019 - 12:15PM to Monday, December 2, 2019 - 1:00PM