A search for direct photon production in 200 and 300 GeV/c proton-beryllium interactions

doi:10.1016/0370-2693(79)90489-1

Physics Letters B

Volume 88, Issues 3–4, 17 December 1979, Pages 372-378

https://doi.org/10.1016/0370-2693(79)90489-1 Get rights and content

Abstract

A search has been made for direct photon production in pBe interactions at 200 and 300 GeV/c over the kinematic region 1.5 < P_⊥ < 4.0 GeV/c and −0.7 < X_F < 0 (90° < θ_cms < 160°). An excess of single photons above that which is predicted from the measured π⁰ and η⁰ production is observed. Theratio of γ/π⁰ production is calculated assuming that the excess arises from direct photon production. We find that this ratio averages 0.070 ± 0.025 (including systematic errors) in this region of X_F and P_⊥ for our 200 and 300 GeV/c data. We have used our measured value of the η/π⁰ ratio of 0.47 ± 0.10 in the determination of the γ/π⁰ ratio. The variation of γ/π⁰ with X_F, P_⊥, X_R and θ_cms presented.

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¹: Present address: Mitre Corporation, Metrek Division, McLean, VA, USA.

²: Present address: Physics Department, Harvard University, Cambridge, MA, USA.

³: Present address: Brookhaven National Laboratory, Upton, NY 11973, USA.

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A search for direct photon production in 200 and 300 GeV/c proton-beryllium interactions

Abstract

Phys. Lett.

Nucl. Instrum. Methods

Nucl. Phys.

Nucl. Phys.

Nucl. Phys.

Phys. Lett.

Phys. Rev. Lett.

Phys. Rev. Lett.

Phys. Rev.

Phys. Rev.