Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published May 2005 | public
Journal Article Open

Search for correlated high energy cosmic ray events with CHICOS


We present the results of a search for time correlations in high energy cosmic ray data (primary E > 10^14 eV) collected by the California HIgh school Cosmic ray ObServatory (CHICOS) array. Data from 60 detector sites spread over an area of 400 km^2 were studied for evidence of isolated events separated by more than 1 km with coincidence times ranging from 1 µs up to 1 s. The results are consistent with the absence of excess coincidences except for a 2.9σ excess observed for coincidence times less than 10 µs. We report upper limits for the coincidence probability as a function of coincidence time.

Additional Information

© 2005 IOP Publishing Ltd. Received 11 February 2005; Published 24 March 2005. We are grateful for the generous support of Caltech and the Weingart Foundation in initiating the CHICOS project. The donation of the detectors by the CYGNUS collaboration is gratefully acknowledged. Support from the NSF (grants PHY-0244899 and PHY-0102502) and the donation of computers for the project by IBM Corporation are also acknowledged. The volunteer efforts of many high school and middle school teachers [12] have been essential in the deployment and operation of the CHICOS array, and we are delighted to acknowledge their participation. Assistance from M Takeda and S Ho in generating AIRES simulations is gratefully acknowledged.


Files (109.8 kB)
Name Size Download all
109.8 kB Preview Download

Additional details

August 22, 2023
October 13, 2023