Photoproduction of Meson and Baryon Resonances at Energies up to 5.8 GeV

Abstract

In a study of photoproduction at photon energies between 0.3 and 5.8 GeV in a hydrogen bubble chamber, approximately 31 000 events with three, five, or seven outgoing charged particles were analyzed. This paper gives a survey of the experimental procedure and of resonance production in quasi-two-body reactions. The cross sections for the processes $\gamma p\to p{\pi }^{+}{\pi }^{-}$, $\gamma p\to p{\pi }^{+}{\pi }^{+}{\pi }^{-}{\pi }^{-}$, $\gamma p\to p{\pi }^{+}{\pi }^{+}{\pi }^{+}{\pi }^{-}{\pi }^{-}{\pi }^{-}$, $\gamma p\to \mathrm{pV} (V={\rho }^0,\omega ,\phi )$, $\gamma p\to p\eta$, $\gamma p\to p{X}^0$, $\gamma p\to {\Delta }^{++}{\pi }^{-}$, and $\gamma p\to {\Delta }^0{\pi }^{+}$ have been measured as a function of the photon energy. For reactions $\gamma p\to p{\rho }^0$, $\gamma p\to p\omega$, and $\gamma p\to {\Delta }^{++}{\pi }^{-}$, the differential cross sections and density matrix elements are given for various intervals of the photon energy. The photoproduction of vector mesons and $\Delta$ isobars is discussed in terms of several models.