Proton-proton bremsstrahlung at 42 MeV: Measurement of cross sections and comparison with a theoretical calculation

Abstract

Proton-proton bremsstrahlung cross sections have been measured at 42 MeV incident beam energy using a wire chamber spectrometer developed for the study of nuclear reactions with three-body final states. Proton-proton bremsstrahlung events from a 22 cm long gaseous target were detected concurrently over polar angle ranges from 16\ifmmode^\circ\else\textdegree\fi{} to 40\ifmmode^\circ\else\textdegree\fi{} and all kinematically allowed values of event noncoplanarity. The data have been analyzed and compared in two different ways to a theoretical calculation based on the Hamada-Johnston potential. In a conventional analysis, the data were divided into eighteen independent polar angle regions and the $\frac{{d}^{3}\ensuremath{\sigma}}{d{\ensuremath{\Omega}}_{1}d{\ensuremath{\Omega}}_{2}d{\ensuremath{\psi}}_{\ensuremath{\gamma}}}$, $\frac{{d}^{2}\ensuremath{\sigma}}{d{\ensuremath{\Omega}}_{1}d{\ensuremath{\Omega}}_{2}}$, and $\frac{{d}^{2}\ensuremath{\sigma}}{d{\ensuremath{\theta}}_{1}d{\ensuremath{\theta}}_{2}}$ cross sections were determined and compared with the theoretical calculations. In a "global" analysis, the data were compared directly with a theoretically weighted, simulated set of events. The latter comparison was made in terms of a wide range of variables, both in the laboratory and in the center of mass systems. A significant discrepancy between experiment and theory was found in certain parts of the observed phase space.NUCLEAR REACTIONS Bremsstrahlung $p(p, p\ensuremath{\gamma})p$, $E=42.0$ MeV; measured $\frac{{d}^{3}\ensuremath{\sigma}}{d{\ensuremath{\Omega}}_{1}d{\ensuremath{\Omega}}_{2}d{\ensuremath{\psi}}_{\ensuremath{\gamma}}}$, $\frac{{d}^{2}\ensuremath{\sigma}}{d{\ensuremath{\Omega}}_{1}d{\ensuremath{\Omega}}_{2}}$, $\frac{{d}^{2}\ensuremath{\sigma}}{d{\ensuremath{\theta}}_{1}d{\ensuremath{\theta}}_{2}}$; global analysis; compared calculations Hamada-Johnston potential.