I. Ambats

Hadron-proton elastic scattering at 50, 100, and 200 GeV/c momentum

Elastic scattering of hadrons on protons has been measured at momenta of 50, 100, and 200 GeV/c. The meson-proton scattering is found to be independent of momentum and meson type for -t > 0.8 (GeV/c)/sup 2/. The momentum dependence of the pp dip at -t = 1.4 (GeV/c)/sup 2/ was investigated. Slope parameters are given. (AIP)

The SOUDAN 2 detector: The design and construction of the tracking calorimeter modules

SOUDAN 2 is a 960-ton tracking calorimeter which has been constructed to search for nucleon decay and other phenomena. The full detector consists of 224 calorimeter modules each weighing 4.3 tons. The design and construction of the modules are described. The modules consist of finely segmented iron instrumented with 1 m long drift tubes of 15 mm internal diameter. The tubes enable three spatial coordinates and dE/dx to be recorded for charged particles traversing the tubes.

OBSERVATION OF STRUCTURE IN ELASTIC PP SCATTERING AT 100 AND 200 GeV/c ~

The elastic differential cross section for pp scattering has been measured up to a momentum transfer of abs. value t = 3 (GeV/c)

Line reversal breaking in K±N → K° Δ(1236) and K±N charge exchange at 4 and 6 GeV/c

sup 2

The observation of underground muons from the direction of Cygnus X-3 during the January 1991 radio flare

at 100 GeV/ c and 200 GeV/c incident momenta. The 200 GeV/c measurements show a diffractive- like dip at abs. value t = 1.5 GeV/c, while no such dip is seen in the 100 GeV/c data. (NL)

A measurement of polarization in π−p→ K°Λ° at 5 GeV/c☆

Abstract Differential cross sections for the line-reversed reaction pairs K + 0p → K o Δ ++ (1236), K − n → K o Δ − (1236) and K − p → K o n , K + n → K o p have been measured with good statistics at 4 and 6 GeV/ c . The line reversal breaking for the Δ (1236) reactions is found to have no significant variation with energy and to be larger than for the charge exchange reactions. The cross sections for all four reactions show a dip in the forward direction, indicating the importance of spin-flip amplitudes.

Measurement of the polarization parameter in small angle proton-proton elastic scattering at 6 GeV/c

Abstract Muons recorded in the Soudan 2 underground nucleon decay detector from January 1989 to February 1991 have been examined for any correlation with the radio flares of Cygnus X-3 observed during this period. On two nearby days during the radio flare of January 1991 a total of 32 muons within 2.0° of the Cygnus X-3 direction were observed when 11.4 were expected.

Cosmic ray tests of the Zeus barrel calorimeter modules

Abstract We have measured the Λ° polarization in π−p→ K°Λ° at 5 GeV/c, using a data sample of 3709 events. The polarization is positive for small t, passes through zero near t = −0.3 (GeV/c)2, and becomes large and negative at larger t, consistent with a value of −1.0 for t between −0.7 and −1.6(GeV/c)2.

First results from the Soudan 2 proton decay experiment

Abstract The polarization parameter in pp elastic scattering was measured at 6 GeV/ c with fine t resolution for 0.02 t 2 using a polarized proton beam with Effective Mass Spectrometer at the Zero Gradient Synchrotron. The polarization rises like √− t in the interval 0.02 t 2 , No statistical significant structure was found in this region of momentum transfer.

Simultaneous Air Shower and Deep Muon Observations at Soudan

Abstract The ZEUS barrel calorimeter consists of 32 wedge-shaped modules constructed using alternate layers of depleted uranium and scintillator with one radiation length sampling. In this paper we summarize tests made on 22 of these modules by measuring their response to hardened cosmic rays. We describe the cosmic ray facility, the data taking, the track reconstruction, the data analysis and the module testing. These tests include the uniformity, both tower-to-tower and module-to-module, in the response to minimum ionizing particles, the mapping of this response as a function of lateral position of the particles inside a given tower, and the measurement of the number of photoelectrons produced by a minimum ionizing particle. In addition, we present data on the stability of the current in the photomultiplier tube generated by the natural radioactivity of the uranium.