Search

Using modularized NaI(Tl) detectors, we carried out a high-statistics measurement of inclusive π o and η spectra in antiproton annihilation at rest in a liquid D 2 target. We obtained the following two-meson yields (branching ratios) per \bar p N ( N = p or n ) annihilation: 0.19± 0.09% for π o ω, 1.07±0.19% for π o ρ o , 0.057±0.018% for π o η, 0.0123±0.0055% for π o π o , 0.02±0.02% for π o ρ - , 0.202±0.031% for π o π - , 0.49±0.12% for ηω, 0.45±0.15% for ηρ o , and 0.91±0.22% for ηρ - .

Multiple scattering of MeV protons and nitrogen ions on amorphous foils has been studied by simulation using Monte Carlo method, where Moliere's single-scattering theory is used as a basis. The cases of different mean numbers of scattering (\(4{

The cross section for the 27 Al(p, 3pn) 24 Na reaction was measured at 12 GeV in order to establish the calibration method of intensity monitors of the 12 GeV primary proton beam at KEK. The measured cross section of 8.1±0.9 mb is consistent with other measurements performed in energy regions close to 12 GeV.

Multiple scattering of protons (0.407, 0.851 and 1.45 MeV) and nitrogen ions (1.28 and 2.29 MeV) on copper has been studied. The observed angular distributions are compared with Moliere's theory and some deviations are found. However, these can be diminished by introducing the effective atomic number, z eff of incident ions. The appropriate z eff 's are estimated as 0.87, 0.90 and 0.94 for the protons, respectively. The values 5.2 and 6.2 are obtained for the respective nitrogen ions. The effective atomic number is attributed to the electron screening of slow ion during the collision process.