C. Michael

Amplitude analysis of πN scattering at 6 GeV/c

Abstract The moduli and relative phases of the π N scattering amplitudes are extracted directly from 6 GeV/ c data. The resulting amplitude structure at the cross-over and at t = −0.6 GeV 2 is analyzed and compared with high-energy models. The helicity structure of the I t = 0 component is determined and predictions for R parameter measurements are given.

ELASTIC PION--DEUTERON SCATTERING AT HIGH ENERGIES.

Abstract Elastic pion-deuteron scattering at 3.65 and 3.75 (GeV/ c ) is analysed on the basis of Glauber theory, particular attention being paid to the deuteron D-state and to the spin dependence and phase variation of the pion-nucleon amplitudes. The good overall agreement between theory and experiment would be further improved with a larger value of the deuteron quadrupole form factor than that given by a Hamada-Johnston type wave function.

Regge-pole models for kaon-nucleon scattering

Abstract A fresh analysis of high energy kaon-nucleon scattering is made, in terms of P, P′, ω, ω′, ϱ and A 2 Regge poles, in the range 0 ⩽ − t ⩽ 1 (GeV/ c ) 2 . High energy data are supplemented by information extracted from low-energy amplitudes, through finite energy sum rules. Within this framework, various alternative models are constructed. Predictions are made for K + p and K − p polarization, and for the regeneration cross section K 0 2 + p → K 0 1 + p .

High-energy production and decay of vector and tensor mesons

Abstract The available charge-exchange data for π N → ϱ N, π N → ω N and ϱ − ω interference effects in the momentum range 6–17 GeV /c are analyzed. Duality considerations are used to constrain as much as possible the exchanged Regge poles and also to relate their contributions to those made by the same Regge exchanges in π N → f 0 N and π N → A 2 N. Combined with an empirical investigation of the Regge cut contributions, this allows a simultaneous description of vector and tensor meson production. The resulting amplitudes are used to predict interference effects in the common KK decay channel of f 0 and A 2 . Other predictions include K ∗ (1420) and K ∗ (1420) production, and many polarization effects.

Polarization relations in charge and hypercharge exchange reactions

Abstract Relations between polarizations in charge and hyperchange exchange reactions are derived. The idea is that K∗(890) and K∗∗(1400) exchange, including unspecified absorptive corrections, are related to ϱ and A2 exchanges by SU(3) octet symmetry, with a scale factor to represent symmetry breaking between the ϱ−A2 and the K∗−K∗∗ trajectories. This hypothesis is consistent with the present data on K N → πΣ(πΛ) and πN → KΣ(KΛ). It leads to simple relations between the polarized cross sections P dσ/dt, relating the above reactions to K − p → K o n , K+n → Kop, π−p → πon, π−p → νon. Predictions are made, on this basis, for polarization in K−p → Kon, K+n → Kop and π−p → νon at 4 GeV/c and for K − p → K o n at 7 GeV/c. Finally, some supplementary conjectures lead to predictions about polarization in baryon-baryon and baryon-anti-baryon reactions, np → pn, p p → n n , p p → Λ Λ , etc., and also in KLop → KSop regeneration.

The ϵ0/Λ0 ratio in K+ photoproduction and SU(3)

Abstract A simple analysis of K ∗  K ∗∗ exchange in K + photoproduction provides an explanation of the ϵ 0 /Λ 0 ratio in terms of the known non strange vector-tensor meson couplings.

Double Regge pole exchange and K−p backward scattering☆

Abstract An estimate of the double Regge exchange contribution to dσ/du (K−p) at u=0 suggests that a break in the energy dependence from the presently observed s−10 to an s−3 behavior should occur at about 5 GeV/c. Further tests of the model are discussed.

Lattice action sum rules

Abstract We develop identities which relate the “energy” in the colour fields to the mass of a system using lattice gauge theory techniques. Applications are made to glueballs, static quark potentials and glue-lump states. The colour electric and magnetic components are extracted and discussed.

η and η′ production at high energies

Abstract We discuss η and η ′ production by pseudoscalar mesons. Small η − η ′ mixing is found. Production mechanisms are considered, and an explanation is given for the striking dipwhich is observed in the K − p → ηλ cross-section at − t ∼ 0.4 GeV 2 .

EXCHANGE DEGENERACY, DUALITY, AND REGGE CUTS.

Abstract Duality leads to exchange degeneracy for Regge trajectories, and empirical evidence is presented that such a degenerate scheme is not satisfied. A substantial improvement results from the inclusion of Regge cut corrections. These corrections are discussed, separating for clarity the P and non-P contributions to the cut. Application is made to pairs of line reversed reactions such as KN and KN charge exchange, and π+p → K+Σ+ and K−p → π−Σ+.