No abstract available

[en] In the text of this letter Yang discusses phase shifts for pion plus-proton and pion minus-proton interactions and predicts cross sections and angular distributions for these interactions

No abstract available

[en] Numerical upper bounds are found for the total spin-flip cross section when the total cross section and the forward slope are known and the partial waves are unitary. (author)

[en] The location of zero of forward π^-p amplitude is calculated by the method based on the statistical approach of the representation of data by analytic functions. The result differs slightly from the value obtained previously by a different method. The correlation between the values of scattering lengths and the position of zeros is discussed. (author)

[en] As a continuation of the report given at the 10. Rochester Conference, recent measurements of charge-exchange cross section and π⁰ production in π^--p interactions are presented here. Section 1 gives a summary of the known results for the elastic, inelastic, and charge-exchange cross sections. Section 2 presents the behavior of the cross sections in the T=1/2 state, in order to discuss the resonances at 600 and 890 MeV. Section 3 discusses the charge-exchange scattering and the interference term between the T=1/2 and T=3/2 states. Section 4 presents some comments on inelastic processes. This report is reprinted from 'Reviews of Modern Physics', Vol. 33, No. 3, 362-367, July, 1961

[en] We have begun a program designed to study hard quark-quark scattering with exclusive reactions, focusing on quasi-elastic two-body reactions with all possible quark flavor exchanges. Examples are π^-p → π^-p, rho^-p, π⁺Δ^-, K⁺Σ^-, or KΛ. Of the two-body exclusives, only elastic scattering had been measured at such large t previous to our experiment. By comparing the relative importance of different final states, the energy dependence of the production ratios of these states, the prominence of resonances such as rho^- over background in this region, and measuring polarizations where accessible, we have collected a large body of data on hard scattering in a completely new domain. Previously, essential all short distance QCD tests have been for inclusive processes. We have taken data with both negative and positive incident beam at 10 GeV/c on a hydrogen target and will present the first results, for π^-p → π^-p and rho^-p at THETA/sub cm/ = 90⁰, -t = 9 GeV²/c². The apparatus consists of a magnetic spectrometer, with Cerenkov particle identification, which selects stable charged particles (protons in this case) at high momentum near 90⁰ in the center-of-mass. A large aperture array of PWCs observes the recoil particle or charged decay products. Cross sections are extremely low, approximately a 1 nb/(GeV/c)² for elastic scattering. We will report on a sample of more than 1000 π^-p elastic events, and on rho^-p, where the rho^- decay distribution was observed. We find a surprisingly large rho^-p cross section in this large momentum transfer region, with rho^-p about half the elastic cross section, and a striking spin alignment of the rho^-

[en] The values for polarization and asymmetries are presented for the reactions π^-p → π⁰n, π^-p → eta n, π^-p → eta'(958)n, π^-p → f(1270)n at 40 GeV/c. New phenomena have been discovered: a local minimum in the crossover region for πp → eta n and non zero polarization (-20%) for πp → eta n at/t/ = 1(GeV/c²). The results are compared with the calculations of diferrent theoretical models

[en] Measured values of the polarization parameter for π sup(+)p scattering at five different energies between 94.5 and 193.3 MeV are reported. An energy-independent phase shift analysis of P data together with the cross-section data is presented. The improvements in the precission of the non-resonant phase-shifts obtained with the inclusion of the P measurements at different energies are discussed

[en] An OZI suppressed channel with variable mass, namely the reaction π^-p → phi phi n, has been used as a filter which allows resonating gluons or glueballs to pass, while strongly rejecting conventional quark-built hadronic states. The breakdown of the OZI suppression signals a glueball. Glueball mass and particle width estimates are discussed. Reasons why g/sub T/'s have not been seen in other channels, particularly the decay of J/psi, are considered. 34 refs., 9 figs