Fermilab Joint Experimental-Theoretical Seminar

  • Date: Oct. 24, 2003

  • Speaker: Stefan Westerhoff (Columbia University)

  • Title: "HiRes: Mapping the High Energy Universe"

  • Abstract:
    The High Resolution Fly's Eye (HiRes) Experiment measures the energy spectrum, chemical composition and arrival directions of cosmic rays above 1018 eV. By mapping the Universe at these highest particle energies, HiRes will help to bring us closer to an understanding of where these particles come from, how they are accelerated, and how they travel astronomical distances. Located in the dry atmosphere of the Utah desert, the HiRes detector consists of a large number of focusing mirrors that image fluorescence light from distant air shower cascades onto arrays of photomultiplier tubes. HiRes comprises two detector sites that provide stereoscopic observations of cosmic ray induced air showers with unprecedented energy resolution and angular resolution. In addition to a discussion of recent measurements of the energy spectrum of cosmic rays, this talk will focus on first results from stereoscopic data. These include a measurement of the primary chemical composition, and a search for anisotropies in the cosmic ray arrival distribution, with emphasis on the highest energies, where previous experiments have observed clustering.

    Send comments to Marcela Carena and Bogdan Dobrescu: wine@fnal.gov