학술논문
Measurement of double polarisation asymmetries in $\omega$-photoproduction
Document Type
Working Paper
Author
Eberhardt, H.; Jude, T. C.; Schmieden, H.; Anisovich, A. V.; Bantes, B.; Bayadilov, D.; Beck, R.; Beloglazov, Yu.; Bichow, M.; Boese, S.; Brinkmann, K. -Th.; Challand, Th.; Crede, V.; Diez, F.; Drexler, P.; Dutz, H.; Elsner, D.; Ewald, R.; Fornet-Ponse, K.; Friedrich, St.; Frommberger, F.; Funke, Ch.; Gottschall, M.; Gridnev, A.; Gruener, M.; Gutz, E.; Hammann, Ch.; Hannappel, J.; Hartmann, J.; Hillert, W.; Hoffmeister, Ph.; Honisch, Ch.; Jaegle, I.; Kaiser, D.; Kalinowsky, H.; Kalischewski, F.; Kammer, S.; Keshelashvili, I.; Kleber, V.; Klein, F.; Klempt, E.; Koop, K.; Krusche, B.; Kube, M.; Lang, M.; Lopatin, I.; Maghrbi, Y.; Makonyi, K.; Metag, V.; Meyer, W.; Mueller, J.; Nanova, M.; Nikonov, V.; Novotny, R.; Piontek, D.; Reeve, S.; Reicherz, G.; Rostomyan, T.; Runkel, S.; Sarantsev, A.; Schaepe, St.; Schmidt, Ch.; Schmitz, R.; Seifen, T.; Sokhoyan, V.; Sumachev, V.; Thiel, A.; Thoma, U.; Urban, M.; van Pee, H.; Walther, D.; Wendel, Ch.; Wiedner, U.; Wilson, A.; Winnebeck, A.
Source
Subject
Language
Abstract
The first measurements of the beam-target-helicity-asymmetries $E$ and $G$ in the photoproduction of $\omega$-mesons off protons at the CBELSA/TAPS experiment are reported. $E$ ($G$) was measured using circularly (linearly) polarised photons and a longitudinally polarised target. $E$ was measured over the photon energy range from close to threshold ($E_\gamma = 1108$~MeV) to $E_\gamma = 2300$~MeV and $G$ at a single energy interval of $1108 < E_\gamma <1300$~MeV. Both measurements cover the full solid angle. The observables $E$ and $G$ are highly sensitive to the contribution of baryon resonances, with $E$ acting as a helicity filter in the $s$-channel. The new results indicate significant $s$-channel resonance contributions together with contributions from $t$-channel exchange processes. A partial wave analysis reveals strong contributions from the partial waves with spin-parity $J^P=3/2^+, 5/2^+$, and $3/2^-$.
Comment: 6 pages, 6 figures
Comment: 6 pages, 6 figures