An Analysis of the Charged Particles Emitted Following Negative Muon Absorptions in Photographic Emulsions

Abstract

663:Calculations have been performed for the energy distribution of alpha particles and protons' following the negative muon absorption in photographic emulsions. Three shapes, (I) Chew-Goldberger distribution, (II) Fermi gas at kT=O and (III) Fermi gas at kT=9 MeV, are' assumed for the proton momentum distributions in the nucleus and the muon absorption probability is calculated for the single particle process. Assuming that the total kinetic energy of produced neutron is imparted into the compound nucleus, we apply the statistical theory' to emission processes.With the assumption of (III) for Ag and Br, the energy distributions of emitted alpha' particles have been well explained by the calculations using the statistical theory, but the rate of proton emission has come out to be too small. If it is assumed that most of produced neutrons were directly emitted, (I) may explain the energy spectrum of emitted particles. In (II), the emission rate is too small. As for the absorption probability, all three shapes shoW' reasonable agreement with experiment.

Delayed muon induced fission of209Bi and the role of meson-exchange currents

“…muon absorption on one or on two nucleons, result in different excitation energies of the residual nucleus. Because the muon neutrino carries the main part of the available energy, muon capture on quasi-free protons results in a nuclear response function with excitation energies centered around 20 MeV [14][15][16][17][18][19][20][21]. Especially for the capturing nucleus 2~ the excitation energy has been found to be 17.9 MeV [18] and 16.7 MeV [20].…”