Low transverse momentum photon production in proton-nucleus collisions at 18 GeV/{ital c}

Journal Article · Tue Oct 01 04:00:00 EDT 1996 · Physical Review, C

DOI:https://doi.org/10.1103/PhysRevC.54.1918· OSTI ID:390400

Tincknell, M L ^[1]; Clark, R L ^[2]; Woody, C; Lissauer, D; Takai, H ^[3]; Ray, A ^[4]; Gomez del Campo, J; Shapira, D ^[5]; Erd, C; Schukraft, J; Willis, W ^[6]

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1. Purdue University, West Lafayette, Indiana 47907-1396 (United States)
2. Vanderbilt University, Nashville, Tennessee 37235 (United States)
3. Brookhaven National Laboratory, Upton, New York 11973 (United States)
4. Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Calcutta 700064 (India)
5. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)
6. CERN, Geneva (Switzerland)

Inclusive single photon spectra have been measured in the transverse momentum ({ital p}{sub {ital T}}) range from a few MeV/{ital c}up to approximately 1 GeV/{ital c}at various nucleon-nucleon center of momentum rapidities ({ital y}{sub {ital NN}}) in the interval from {minus}2.4{lt}{ital y}{sub {ital NN}}{lt}+0.5 in 18 GeV/{ital c}{ital p}-Be and {ital p}-W collisions. These distributions were used to estimate the inclusive {ital p}{sub {ital T}} and rapidity distributions for {pi}{sup 0} production over approximately the same kinematic range. The measured photon spectra are compared with the expected distribution of photons from {pi}{sup 0} decays and hadronic bremsstrahlung in order to search for new sources of {open_quote}{open_quote}soft{close_quote}{close_quote} photons at low transverse momentum. The results indicate no anomalous sources of soft photons in either {ital p}-Be or {ital p}-W interactions at these energies. The {ital p}-W data at forward angles set a limit on any excess of low {ital p}{sub {ital T}} photons at {lt}2.65 times hadronic bremsstrahlung at the 99{percent} C.L. {copyright} {ital 1996 The American Physical Society.}

• Research Organization: Brookhaven National Laboratory
• DOE Contract Number: AC02-76CH00016; FG02-88ER40412
• OSTI ID: 390400
• Journal Information: Physical Review, C, Journal Name: Physical Review, C Journal Issue: 4 Vol. 54; ISSN PRVCAN; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BREMSSTRAHLUNG
DISTRIBUTION
GEV RANGE 10-100
NUCLEON-NUCLEON INTERACTIONS
PARTICLE PRODUCTION
PARTICLE RAPIDITY
PHOTONS
PIONS NEUTRAL
PROTON REACTIONS
SPECTRA
TRANSVERSE MOMENTUM