Hyperon experiments at Fermilab

This report reviews a series of experiments performed in a short neutral/charge hyperon beam in the Meson Laboratory at Fermilab. The first measurements were production cross sections for 300 GeV protons: p+Be->Λ, anti Λ, K0sub(s) at secondary momenta between 60 and 250 GeV/c and fixed laboratory angles between 0 and 10 mrad. At the larger production angles the Λ's were polarized: (Psub(Λ))proportional0.15. The proton energy increased to 400 GeV. The Λ magnetic dipole moment was obtained: μsub(Λ) = (-0.6138+-0.0047)μsub(N) in units e(h/2π)/2msub(p)c. Production and polarization of anti Λ, Ψ0, anti Ψ0, Σ+, Σ-, and Ψ- were studied in roughly the same kinematic range as the Λ. The A dependence of the cross sections from Be, Cu, Pb targets was measured, and production cross sections pp->Λ, anti Λ, K0sub(s), from a liquid hydrogen target were obtained. The magnetic moments μsub(Ψ0)=(-1.253+-0.014)μsub(N,) μsub(Ψ-)=(-0.69+-0.04)μsub(N), μsub(Σ+)=(+2.31+-0.03)μsub(N), and μsub(Σ-)=(-0.89+-0.14)μsub(N) resulted from further work with the precession of polarized hyperons. Although the production cross sections and polarization are considered from the triple Regge point of view, the main theme of the report is the constituent quark model, which, combined with some ancillary assumptions gives a better than qualitative coherent picture of all of these phenomena. (orig.)