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U.S. Department of Energy
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Measurement of vector meson and direct photon production at large transverse momentum at the CERN ISR. [Cross section]

Conference ·
OSTI ID:6626899
The production at large transverse momentum of low mass electron pairs was investigated at the CERN Intersecting Storage Rings using lithium/xenon transition radiation detectors and liquid argon calorimeters. Production of the vector mesons rho/sup 0/, ..omega../sup 0/, and phi was observed with cross sections consistent with the assumptions that rho/sup 0/, ..omega../sup 0/, and ..pi../sup 0/ production are nearly equal at large p/sub t/ and that phi production is suppressed by about an order of magnitude relative to rho/sup 0/ and ..omega../sup 0/ production. The observed low mass virtual photon continuum between masses of 200 and 500 MeV was consistent with estimates of Dalitz decays plus predictions of the vector dominance model. The measured cross section for virtual photon production enabled a limit of (0.5 +- 1.0) percent to be placed on the ratio of direct real photon production to ..pi../sup 0/ production.
Research Organization:
Brookhaven National Lab., Upton, NY (USA)
Sponsoring Organization:
USDOE
DOE Contract Number:
EY-76-C-02-0016
OSTI ID:
6626899
Report Number(s):
BNL-24557; CONF-780353-2
Country of Publication:
United States
Language:
English