arXiv:1007.0777·v4·Nuclear Experiment
Study of the gp-->etap reaction with the Crystal Ball detector at the Mainz Microtron(MAMI-C)
E.F. McNicoll🇬🇧 · S. Prakhov🇺🇸 · I.I. Strakovsky🇺🇸 · P. Aguar-Bartolomepmainz🇩🇪 · L.K. Akasoy🇩🇪 · J.R.M. Annand🇬🇧 · H.J. Arends🇩🇪 · R.A. Arndt🇺🇸 · Ya.I. Azimov🇷🇺 · K. Bantawa🇺🇸 · R. Beck🇩🇪 · V.S. Bekrenev🇷🇺
Abstract
The gp-->etap reaction has been measured with the Crystal Ball and TAPS multiphoton spectrometers in the energy range from the production threshold of 707 MeV to 1.4 GeV (1.49 =< W >= 1.87 GeV). Bremsstrahlung photons produced by the 1.5-GeV electron beam of the Mainz Microtron MAMI-C and momentum analyzed by the Glasgow Tagging Spectrometer were used for the eta-meson production. Our accumulation of 3.8 x 10^6 gp-->etap-->3pi0p-->6gp events allows a detailed study of the reaction dynamics. The gp-->etap differential cross sections were determined for 120 energy bins and the full range of the production angles. Our data show a dip near W = 1680 MeV in the total cross section caused by a substantial dip in eta production at forward angles. The data are compared to predictions of previous SAID and MAID partial-wave analyses and to thelatest SAID and MAID fits that have included our data.
Comments: 15 pages, 12 figures