[en] anti pp annihilation cross sections into 2-, 4- and 6-prong topologies, and the exclusive annihilation cross sections for the π⁺ π^-, K⁺ K^-, π⁺ π^- π₀, π⁺ π⁺ π^- π^-, π⁺ π⁺ π^- π^- π₀, π⁺ π⁺ π⁺ π^- π^- π^-, and π⁺ π⁺ π⁺ π^- π^- π^- π₀ channels in the momentum range 374-680 MeV/c were measured. No prominent structure was observed in the momentum dependence of any of the above cross sections, but a small enhancement in the cross section was observed at 490 MeV/c corresponding to the S meson mass in the topological, and π⁺ π^- π₀ and π⁺ π⁺ π^- π^- π₀ cross sections. If the existence of the S meson with a mass and width of 1935.5 and 2.8 MeV/c₂ is assumed, our measurement gives a total resonant annihilation cross section into charged particles of 10.0 +- 3.0 mb. (orig.)

[en] The dp total, inelastic, and elastic total and differential cross sections were measured at 10 momenta in the deuteron momentum range 2.0-3.7 GeV/c. The slope parameters of the forward portions of the differential cross sections were also measured. The dp total cross sections and the elastic differential cross sections were in fair agreement with a Glauber model calculation. The elastic total cross sections, however, were in disagreement with the calculation due most likely to the neglect of spin dependence and the effect of Fermi motion in the calculation. (orig.)

[en] We have studied the np → ppπ^- reaction in the incident-momentum range 1.0-1.9 GeV/c using the dp → ppπ^- reaction in terms of the impulse approximation. The reaction cross sections and the I=0 cross sections were measured. The I=0 cross sections were almost zero except at 1.89 GeV/c which indicates the onset of a substantial contribution from the I=0 amplitude. The inclusive π angular distribution showed asymmetry also at 1.89 GeV/c which was interpreted as an interference between the I=0 and 1 amplitudes. The Δ-production fraction, Δ angular distributions and Δ-decay density matrices were measured. These measurements indicate that Δ-production is substantial in the np → ppπ^- reaction in our momentum range and that it is induced by pion exchange. Comparison with data from the pp → ppπ⁰ reaction also confirms the dominance of the nucleon-nucleon I=1 state in the np → ppπ^- reaction. (orig.)

[en] Exclusive anti pp pionic annihilation reactions in the momentum range of 403 to 670 MeV/c were analysed in terms of intermediate states involving resonances. The fractions of the various intermediate states showed no significant dependence on the incident momentum. They were compared with a statistical model incorporating SU(3) symmetry. The agreement between the model and data was moderate and qualitative. The exclusive as well as topological cross sections were compared with the same statistical model and a potential model incorporating quark rearrangement. The agreement with the latter model was better than with the first in general, but it was still mostly qualitative. (orig.)

[en] anti pp elastic total and differential cross sections were measured at 17 incident momenta in the range 374-680 MeV/c. No prominent feature was seen in them to clearly indicate the existence of the S-meson. There is, however, a small enhancement at the S-meson mass, which is equivalent to the elastic total cross section of 4.6 +- 2.1 mb. The behavior of the Legendre expansion coefficients of the angular distributions with incident momentum agrees well with the prediction of the OBE model of Bryan and Phillips. (orig.)

[en] The authors have measured the anti pp total cross sections at 24 incident momenta from 373 to 734 MeV/c and observed an enhancement in the cross section at around 490 MeV/c. A fit to a Breit-Wigner form superposed on a smoothly decreasing background gives the mass of this enhancement to be 1935.5+-1.0 MeV/c² with a width of 2.8+-1.4 MeV/c². The resonant total cross section is 14.5+-3.9 mb. (Auth.)

[en] A compact and nearly maintenance-free timing calibration system using a dye laser has been constructed for the KEK TRISTAN TOPAZ barrel TOF counter system. Its timing resolution has been measured to be about 50 ps. The characteristics of its major components have been obtained so as to thoroughly understand their functions and performances. (orig.)

[en] The breakup reaction dp→ppn was studied at 10 momenta in the incident-deuteron-momentum range 2.0--3.7 GeV/c. The magnitudes of the differential cross sections for quasielastic scattering of protons and neutrons are lower by 10%--20% than those of the free pp and np elastic cross sections. However, the shapes of the quasielastic and free elastic differential cross sections are quite similar except possibly in the very forward region

[en] The pp total, elastic, and all the inelastic cross sections were measured at 11 momenta in the range 0.9-2.0 GeV/c. No clear structure was observed in their momentum dependences. The momentum dependence of the total cross section agrees quite well with the result of a phase-shift analysis by Arndt. Our measurement of the ppπ⁰ and pnπ⁺ cross sections served to normalize the earlier systematic but relative and extrapolated measurements of these cross sections over a narrower momentum range. Calculations by Koenig and Kroll based on a pion exchange model including the effect of an I = 1 dibaryon did not fit the single-pion production cross section. (orig.)

[en] The total and differential p-barp charge-exchange cross sections were obtained at seven momenta in the range 480 to 728 MeV/c. The total cross sections are roughly consistent with other data. The momentum dependences of the Legendre coefficients a₁/a₀, a₂/a₀, and a₃/a₀ of the differential cross sections do not agree well with the predictions of the Bryan-Phillips model, unlike the case of elastic scattering