New data a r e presented on c r o s s sections and angular distributions of resonances produced in the reactions ~-d -R O a -d and ~-d--fiOa-np, at 5.5 GeV/c. The production mechanisms and decay angular distributions a r e analyzed for the R* (890), R*(1420), and A(1236) resonances. The RO~-np, final state i s discussed in terms of the Veneziano B5 model and also using the Van Hove longitudinal-phase-space technique. In addition, a Regge model with absorption i s used to describe A(1236) production in the reaction -RA (1236). The spherical harmonic moments of the P~Tsystem a s a function of K T mass a r e discussed for the reaction K-d --ROT-p + MM. D. J O H N S O N e t al. EVENTS /a025 GoV --deuteron form factor, of course, inhibits R*-(890)

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A measurement of charged-particle production is reported for the forward region in events triggered by high-transverse-momentum (PJ.) jets and single particles. The momentum distributions of forward-going particles are observed to scale in a simple PJ. -dependent longitudinal variable. Forward-going (beam) jets are observed to be tilted away from the original direction by an amount which agrees with muon-pair data when interpreted in a parton (quantum-chromodynamics) model.

We have analyzed 370 000 pictures taken in the 30-inch hydrogen bubble chamber exposed to the 5.5-GeV/c separated K~ beam 1 at the Argonne zero-gradient synchrotron (ZGS). Light particle contamination in the beam was £5% when calculated from a r scan of the film. A Cerenkov counter operated during the exposure indicated the same high purity. About 5000 two-prong events with an associated A decay have been found. After kinematic analysis, these yielded 328 fits to the final state A77 + TT"" and 89 fits to 2°77 + 7r~.When more than one hypothesis produced a fit to a given event, a x 2 probability cut was used to exclude all fits having a probability 5 times less than that for the best fit. After this selection, all events fitting the hypothesis ATT + 77~ with a \ 2 probability >1% were classified as ATT + TT~ events. Of the remaining events, all those fitting the Z°Tf + 7r~ hypothesis with a X 2 probability >1% were classified as £°7r + 77~" events. These criteria yield a rather pure sample of the four-constraint AIT + IT~ final state. 2 The two-constraint fits to S°7r + 7r"~ have some (unknown) contamination from the A7T + ir~n° events, but this uncertainty is not important for the present results. Because of the high-beam purity, contamination due to events originating from pions can be neglected. 3 The Dalitz plot and the mass-squared projection for the events classified as ATI + IT~ are shown in Fig.

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The results described in this paper were obtained from an analysis of bubble-chamber pictures of K~p interactions at incident momenta of 4.1 and 5.5 GeV/c. This paper reports the results on quasi-two-body final states, which are observed to be predominantly peripheral. In the final states Ap, Aw, A<£, and FI* + (1385)TT", the exchange mechanisms were investigated in terms of the density-matrix formalism. In general, vector-meson exchange appeared to be dominant, and in particular the decay distributions of the Yi* + (l385)w~ final state were in good agreement with the predictions of the Stodolsky-Sakurai model. Several reactions show small backward peaks expected from baryon exchange. The prediction of the independent quark model and other symmetry schemes that the forward cross sections for Ap° and Aw production should be equal is well satisfied by the present data. We also report measurements of the properties of various resonant states. We find a mass and width for the Fi*(1695) of M =1700=b20 MeV, F=130db25 MeV. The dominant decay mode is Ax + , but limits are placed on other possible channels.