Break-up and Coherent Photoproduction of η Mesons on the Deuteron

By admin Last updated فبراير 14, 2019

Break-up and Coherent Photoproduction of $η$ Mesons on the Deuteron

P. Hoffmann-Rothe, M. Krebeck, J. Hey, M. Breuer, G. v. Edel, E. Hourany, M. Rigney, J. Ajaka, G. Anton, J. Arends, G. Berrier-Ronsin, W. Beulertz, G. Blanpied, A. Bock, J.-P. Didelez, K. Helbing, R. Maass, G. Nöldeke, B. Preedom, B. Richie, L. Rosier, B. Saghai, M. Schumacher, and F. Smend

Phys. Rev. Lett. 78, 4697 – Published 23 June 1997

Abstract

We present new break-up and coherent data for $η$ meson photoproduction on the deuteron, using a deuterium target and tagged bremsstrahlung photons up to 1 GeV. The differential cross sections for the coherent process were measured from threshold to 800 MeV. They are much smaller than those previously reported. The break-up channel provides a direct measurement of the neutron to proton differential cross section ratios. At the $S_{11} (1535)$ resonance peak, $σ_{n} / σ_{p} = 0.68 \pm 0.06$ leading to an isoscalar to isovector amplitude ratio of $A_{s} {/ A}_{υ} = 0.096 \pm 0.02$ .

Received 26 November 1996

DOI: https://doi.org/10.1103/PhysRevLett.78.4697