Collaborative International Research on High Resolution Charge Measurements with Direct Cerenkov Light

University Of Utah, Salt Lake City UT

Investigators

Abstract

This research will examine the possibility of observing `Direct Cherenkov' light in cosmic ray air showers to provide high resolution measurement of the primary charge of the incoming cosmic ray. The technique exploits the details of images of air Cherenkov light emitted by the charged primary cosmic rays as they interact with the Earth's atmosphere. . The results of this research may lead to a new capability which may shed light on the origin of high energy cosmic rays, and may also provide new capabilities with implications for improved research in high energy gamma ray astronomy, simulations of nuclear interactions in extensive air showers, and searches for rare, exotic charge states in cosmic rays such as magnetic monopoles and ``quark matter''. It is possible that data from the two existing Gamma Ray observatories (HEGRA and the Japanese Seven Telescope Array) may have sufficient resolution to begin to see the first signatures of Direct Cherenkov light emission in cosmic rays as they propagate through the atmosphere. The unambiguous identification of Direct Cherenkov light in even a few cosmic ray air showers would provide evidence that this light may be employed as a useful tool in high energy astrophysics studies. A key question that may be resolved is whether Direct Cherenkov light can be unambiguously identified. By using the archival Gamma Ray Observatory data, it may be possible to quickly verify the accuracy of this new high-resolution measurement technique. A second goal of this proposal is to develop simulations of atmospheric cosmic ray interactions by heavy elements (nuclear mass heavier than Iron), and use these simulations to establish reliable flux limits on these particles through comparison with archival data from the High Resolution Fly's Eye and BLANCA cosmic ray observatories. The research will support development of a realistic heavy nuclei simulation that can provide simulation of these particle interactions in the Earth's atmosphere. The resulting heavy nuclei simulation tools will be made available to the general community, as well as a database of simulated events. This research provides support for international travel by the PI to perform the analysis on the data in their HEGRA and Japanese databases as well as some undergraduate student research support. The undergraduate research will include students at the University of Utah by involving them directly in the processing and analysis of the archival data as well as development of the heavy nuclei simulation database. Students will become involved with weekly science discussions of current topics in physics and astronomy as well as present results of their work in University seminars and regional American Physical Society meetings.