The π0 inclusive cross section for c.m. production angles θ=90° and 22°>~θ>~5° at c.m. energies of s=23 and 53 GeV has been measured. This cross section is strongly dependent on both θ and s at small angles. The hypothesis of radial scaling is shown to be incapable of incorporating both θ and s dependence of the cross section. A recent quantum-chromodynamics calculation is in qualitative agreement with our results.
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The inclusive production of π 0 at large values of p T in pp collisions at the ISR has been studied. In this experiment the two photons are resolved and separately measured for p T values of up to 6 GeV/ c , giving confidence that the desired signal has been separated from various backgrounds.
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We report on the experimental results obtained at the ISR for the η particle production at 90° and √ s = 30.6 and 53.2 GeV. We determine the invariant cross section and the p t distribution in the interval 1 ⩽ p t ⩽ 5 GeV/ c . We find that the p t distribution has the same shape of the π 0 production and differ from it by a constant factor R 90° = 0.5 ± 0.07.
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We report the results of an experiment made at the CERN ISR to investigate the possible diret production of single photons in pp collisions at √ s = 53.2 GeV at 90° and in the p t interval 2.3 to 5.7 GeV/ c . The value of the ratio R = n γ / n π 0 is compatible with zero for low p t ⪅ 3 GeV/ c but, in spite of the large error, shows a trend to increase for larger p t .
THIS USES THE SO-CALLED D2L TRIGGER (SEE PAPER).
THIS USES THE SO-CALLED D2MAX TRIGGER (SEE PAPER).
THIS USES THE SO-CALLED D2MAX TRIGGER (SEE PAPER).
The inclusive production of ϱ 0 mesons in pp collisions has been measured at five c.m. energies from √ s = 23.6 to 63.0 GeV. The cross sections and the production spectra as a function of transverse momentum and rapidity are discussed.
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Final results of our measurements of elastic proton-proton scattering at the CERN Intersecting Storage Rings (ISR) for c.m. energies √ s from 23 to 63 GeV and momentum transfers | t | from 0.8 to 10 GeV 2 are presented. Absolute differential cross sections have been obtained using the split-field magnet detector facility (SFM) at the five standard energies for integrated luminosities ranging from 0.3 to 4.9 (pb) −1 . The rising total cross section is found to define a scale for diffractive phenomena near the forward peak, including the position of the diffraction minimum near t = −1.4 GeV 2 . The cross section at the minimum is strongly energy dependent, approximately as the ratio of the real to imaginary part of the scattering amplitude in the forward direction. The phase of the scattering amplitude is found to change sign near the minimum. The component of diffraction scattering beyond the second maximum has a much weaker t -dependence than expected in simple eikonal or constituent pictures connecting this region to the forward peak. A further break in slope is observed near t = −6 GeV 2 . There is no evidence for another minimum for t values up to 10 GeV 2 .
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We present the results of a systematic analysis of charge-exchange double dissociation in proton-proton collisions at the CERN Intersecting Storage Rings. The data, obtained with the Split-Field Magnet detector, cover the entire ISR energy range between s = 23 GeV and s = 63 GeV at five standard energies.
CHARGE EXCHANGE DOUBLE DIFFRACTION DISSOCIATION OF PROTONS. THESE CROSS SECTIONS WERE REPORTED IN G. GOGGI ET AL., PL 72B, 265 (1977).
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THE SEMI INCLUSIVE DENSITY MATRICES ARE ALSO GIVEN (P P --> DEL++ P PI- + DEL0 P PI+).
The measurement of the proton-proton total cross section performed by the CERN-Pisa-Rome-Stony Brook Collaboration at the CERN ISR is discussed in detail. The total interaction rate, the elastic scattering rate in the forward direction, and the machine luminosity were measured simultaneously to obtain three different determinations of the total cross section. Consistent results were found, which made it possible to prove the reliability of the Van der Meer luminosity calibration within +-0.9% and to achieve a precision of +-0.6% in the measurement of the total cross section.
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We report on experimental results on deuteron-deuteron elastic scattering at a centre-of-mass energy of √ s = 53 GeV . The data were obtained using the Split Field Magnet detector at the CERN intersecting Storage Rings. The t -dependence of the elastic cross section is measured up to − = 1.5 GeV 2 . We observed a narrow interference minimum in the differential cross section at − = 0.18 GeV 2 . The inclusion of inelastic intermeduate states in the multiple scattering Glauber theory is essential in the description of the data over the entire t -range where discrepancies of up to 25% are observed with the basic theory.
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We report on experimental results on proton-deuteron elastic scattering at a centre-of-mass energy of √ s = 63 GeV . The data were obtained using the Split Field Magnet detector at the CERN Intersecting Storage Rings. The t -dependence of the elastic differential cross section, measured up to − t = 2.0 GeV 2 , is compared with the prediction of an extended Glauber theory including contributions from inelastic intermediate states. Discrepancies of up to 30% with the basic theory are observed in the interference region. The inelastic contributions are essential for the detailed description of the data both in the single- and double-scattering regions.
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