Professor of Physics
Ph.D., 1984 - University of Wisconsin-Madison
Louisiana State University
Department of Physics & Astronomy
347 Nicholson Hall, Tower Dr.
Baton Rouge, LA 70803-4001
Experimental Astrophysics / Particle Physics
Prof. Matthews’ research involves the experimental study of the highest energy cosmic rays at the Pierre Auger Observatory in western Argentina. His group at LSU has been engaged in diverse projects on hardware, electronics, data analysis, and computer simulations. This project is an international collaboration of over 500 scientists and engineers. Prof. Matthews is the Co-Spokesperson of the Collaboration and a Fellow of the American Physical Society. He has been a part of the Auger effort since its inception in 1992.
The aim of the Auger Observatory is to measure the energy, direction, and composition of the highest energy (> 1019 eV) cosmic rays. No known mechanism can fully account for the acceleration of cosmic rays to such enormous energies - energies orders of magnitude beyond what is or ever will be achieved at terrestrial particle accelerators. Their extreme energy ensures that they suffer modest deflections when passing through relatively weak Galactic or intergalactic magnetic fields. Cosmic rays also may interact with the cosmic background radiation, so any observed at earth must have originated at distances within about 100 Mpc. Few possible sources exist so nearby.
The near-linearity of trajectories and closeness of their origins make possible point-source astronomy with the highest energy cosmic rays. Accurate reconstruction of the axes of air showers produced in the earth's atmosphere by these cosmic rays should indicate their celestial source(s). The properties of the air showers also give information on particle interactions in a new energy regime.
An overview and description of the Auger Observatory.
A recent summary of scientific results from the Auger Observatory.
Current and Select Publications
- "The Pierre Auger Cosmic Ray Observatory", Pierre Auger Collaboration [A. Aab et al.], Nuclear Instruments and Methods in Physics ResearchA798 (2015) 172. (arXiv:1502.01323 [astro-ph.IM])
- "Measurement of the cosmic ray spectrum above 4x1018 eV using inclined events detected with the Pierre Auger Observatory", Pierre Auger Collaboration [A. Aab et al.], J. Cosmology and Astropart. Phys, (JCAP) 08 (2015), 049. (arXiv:1503.07786 [astro-ph.HE])
- "An improved limit to the diff use flux of ultra-high energy neutrinos from the Pierre Auger Observatory", Pierre Auger Collaboration [A. Aab et al.], Physical Review D91 (2015) 092008 (arXiv:1504.05397 [astro-ph.HE])
- "Searches for anisotropies in the Arrival directions of the highest energy cosmic rays detected by the Pierre Auger Observatory", Pierre Auger Collaboration [A. Aab et al.], The Astrophysical Journal 804 (2015) 15. (arXiv:1411.6111 [astro-ph.HE])
- "Search for patterns by combining cosmic ray energy and arrival directions at the Pierre Auger Observatory", Pierre Auger Collaboration [A. Aab et al.], European Physical Journal C75 (2015) 269. (arXiv:1410.0515 [astro-ph.HE])
- "Large scale distribution of ultra high energy cosmic rays detected at the Pierre Auger Observatory with zenith angles up to 80o ", Pierre Auger Collaboration [A. Aab et al.], The Astrophysical Journal 802 (2015) 111.(arXiv:1411.6953 [astro-ph.HE])
- "Muons in air showers at the Pierre Auger Observatory: Mean number in highly inclined events", Pierre Auger Collaboration [A. Aab et al.], Physical Review D91 (2015) 032003. (arXiv:1408.1421 [astro-ph.HE])
- A Heitler model of extensive air showers, J. Matthews, Astropart. Phys. 22 (2005) 387.
- Observation of a Neutrino Burst in Coincidence with Supernova 1987A in the Large Magellanic Cloud, (R.M. Bionta et al., Phys. Rev. Lett. 58(1987) 1494.