Interplay between High Energy Astrophysics, Cosmology, and Particle Physics

University Of Wisconsin-Milwaukee, Milwaukee WI

Investigators

Abstract

The PI has a broad research program in particle physics, astrophysics, and cosmology. The first set of his goals exploits the Pierre Auger observatory as an ultra-high-energy particle (UHE) physics laboratory. The PI intends to study the development of UHE cosmic ray (CR) cascades in the atmosphere. To distinguish between the effects of the cosmic ray composition and new effects related to novel hadronic physics, the proposed study will investigate the development of the CR cascades in the atmosphere. Another research area is for the PI to determine the flux of cosmogenic UHE neutrinos due to photomeson production (GZK effect). Once the total amount of data on UHE interactions coming from the Auger Observatory increases, the PI hopes to constrain the number of extra dimensions and probe the possibility of TeV-scale gravity (suggested by having extra spatial dimensions) by studying limits on the production rate of black holes in UHE particle interactions. Observations of the showers triggered by UHE neutrinos will be used to study neutrino interactions and mixing. By studying the development of UHE CR cascades in the atmosphere the PI hopes to identify exotic R-hadrons (standard hadronic states coupled with gluinos), if they exist and are metastable. The detection techniques of HE and VHE gamma rays have recently improved significantly allowing for much better angular resolution and sensitivity of the instruments. A cutting-edge instrument in MeV-sub TeV range GLAST, is scheduled for launch in 2008. The PI hopes to utilize the GLAST capability to shed light on the origin of gamma-ray emission. The PI also intends to study exotic particle physics at the LHC and Ice Cube: probes of quantum gravity, search for R-hadrons. He also intends to study of the "unparticle" parameter space which is the regime where conformal field theories at short distances can affect the physics seen at the LHC. The PI writes for several popular magazines and has appeared on BBC radio to publicize the physics potential of the Ice Cube neutrino telecope at the South Pole. He is also involved with making the Arecibo Radio Observatory in Puerto Rico available for remote observing by high school as well as college students at the University of Milwaukee.