Abstract
We report exclusive measurements for the η photoproduction on a proton target. The differential cross sections and photon beam asymmetries of the γp→ηp reaction are measured in a center-of-mass energy (W) range of 1.82-2.32 GeV and a polar angle range of -1.0<cosθc.m.η<0.6 by using a large acceptance calorimeter (BGOegg) and forward-angle charged-particle detectors at the SPring-8 LEPS2 beamline. The reaction is identified with a kinematic fitting method to select a recoil proton and two photons produced in an η meson decay. A bump structure at W = 2.0-2.3 GeV in the differential cross section is confirmed at extremely backward η polar angles, where the existing data are inconsistent with each other. This bump structure is likely associated with high-spin resonances that couple with ss¯ quarks. The photon beam asymmetries in a wide η polar angle range for the photon beam energies above 2.1 GeV are reported for the first time, providing an additional constraint to nucleon resonance studies at high energies.
Original language | English |
---|---|
Article number | 035201 |
Journal | Physical Review C |
Volume | 106 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2022 Sept |
Bibliographical note
Publisher Copyright:© 2022 American Physical Society.
ASJC Scopus subject areas
- Nuclear and High Energy Physics