4 papers
Probing keV mass QCD axions with the SACLA X-ray free electron laser
Charles Heaton, Jack W. D. Halliday, Taito Osaka +12
Axions are hypothetical particles, proposed to account for the invariance of CP symmetry in quantum chromodynamics. While axions and axion-like-particles are well-motivated by stri…
Laboratory observation of collective beam-plasma instabilities in a relativistic pair jet
J W D Halliday, C D Arrowsmith, A M Goillot +37
We report on a measurement of collective behavior in a relativistic electron-positron pair plasma produced in the laboratory. Using the Fireball platform at CERN's HiRadMat facilit…
Suppression of pair beam instabilities in a laboratory analogue of blazar pair cascades
Charles D. Arrowsmith, Francesco Miniati, Pablo J. Bilbao +28
The generation of dense electron-positron pair beams in the laboratory can enable direct tests of theoretical models of -ray bursts and active galactic nuclei. We have successf…
Bounds on heavy axions with an X-ray free electron laser
Jack W. D. Halliday, Giacomo Marocco, Konstantin A. Beyer +18
We present new exclusion bounds obtained at the European X-ray Free Electron Laser facility (EuXFEL) on axion-like particles (ALPs) in the mass range 10^{-3} eV < m_a < 10^4 eV. Ou…