Photoproduction of ETA Mesons from Hydrogen at Photon Energies Between 0.8 and 1.45 GeV

Author: Rochester, Leon S.

Year: 1968

Degree: Dissertation (Ph.D.)

Advisor: Heusch, Clemens A.

Committee Member: Unknown, Unknown

Option: Physics

DOI: 10.7907/0W0Y-7B43

Abstract

We measured the differential cross section of the process γp → pƞ at the 1.5 GeV Caltech electron synchrotron, at photon energies from 0.8 to 1.45 GeV, at various angles between 45° and 100° in the center of mass. A counter-spark chamber array was used to determine the kinematics of all particles in the final state of the partial mode γp → pƞ (ƞ → 2γ). Analysis of 40,000 pictures yielded 6,000 events above a background which varied with energy from 5% to 30% of foreground. The cross section shows an energy dependence confirming earlier results up to 1000 MeV, but with improved statistics; it then remains roughly constant (at 50° C.M.), to 1.45 GeV. The data show a small angular variation, within the limited range covered, at energies between 1000 and 1100 MeV.

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