[en] We have recently completed the first part of running for experiment E-609 at Fermilab. The E-609 hadron jet experiment uses a 132-segment 8-steradian full azimuth calorimeter with tower structure. Additional parts of the apparatus are described in the paper. A novel triggering system allowed us to take data with many different kinds of triggers simultaneously. We give a preliminary report on data obtained in 400 GeV pp collisions, concentrating on data from two triggers, both of which have no special geometrical requirement for the form of the transverse energy deposition. One of these was a global total E-transverse trigger; the other was a 2-high trigger, which required that 2 or more calorimeter segments (any 2) each give a signal larger than about 1.0 GeV/c. This report further concentrates on the data sample with total transverse energy above 11 GeV. We will present results concerning planarity distributions as well as theta-phi energy flow, for these events. For the globally triggered events in this kinematic region, only a few percent show clear di-jet structure, with clustering, co-planarity, and concentration of high-p_T fragments near the jet axes. For the 2-high events however, at this E-transverse, approximately 30 percent of the events show di-jet structure. The 2-high events constitute only about 15 percent of the global events, but contain virtually all the events which show this clear di-jet structure. Details of the analysis are presented, including studies of whether the features of the di-jet events can be explained by simple random fluctuations

[en] Preliminary results from a search for new particles produced in proton-nucleus collisions at 400 GeV/c are reported. A double-arm spectrometer is used to detect two-body final states where each spectrometer arm has the capability of uniquely identifying π/sup +-/, K/sup +-/, p, anti p, μ/sup +-/, and phi. The J/psi is measured in the μ⁺μ^- mode

No abstract available

[en] In a 400 GeV/c fixed target experiment using a set of geometrical calorimeter triggers we have determinde a cross section for pp collisions producting two high P_T coplanar clusters. This cross section was determined without using jet-finding algorithms or appealing to QCD Monte Carlo calculations. Corrections to the data were made by studying hardware triggers designed for that purpose or using experimental data from e⁺e^- colliders. The magnitude of the experimental cross sections and the P_T slope both agree reasonably well with theoretical QCD predictions for parton-parton scattering that combine non-scaling behavior with fits to recent data from ep, μp, and νp experiments. (orig.)