B. Bošnjaković

ELASTIC SCATTERING OF POSITIVE KAONS ON POLARIZED PROTONS BETWEEN 0.87 AND 2.74 GeV/c. RESULTS AND PHASE-SHIFT ANALYSIS.

Abstract Polarization and differential cross-section data at 16 momenta between 0.86 and 2.74 GeV/ c are presented. (Preliminary data on some of the momenta have been published earlier.) In an energy-independent phase-shift analysis from threshold up to 2.5 GeV/ c , resonant-like as well as non-resonant solutions are found for the P 3 wave. An helicity flip-non-flip decomposition of the partial waves partly supports the indications found in the analyses of other reactions that the pomeron is built up mainly from s -channel helicity non-flip contributions.

Production of high-momentum mesons at small angles at a cm energy of 45 GeV at the CERN ISR

Abstract Inclusive cross sections for the production of π ± and K ± mesons in proton-proton collisions have been measured at a c.m. energy √ s = 45 GeV, in the range 0.41 x p T x = 2 p L/√ s and p L , p T are the longitudinal and transverse components of the momentum of the meson. Within the measured range the p T dependence of the invariant cross section is essentially independent of x and weakly dependent on the type of particle. For all particles the invariant cross sections at fixed p T fall by three orders of magnitude between x = 0.4 and 0.95. Except at the highest values of x and p T , the statistical accuracy is better than 10%. The data are compared with a triple-Regge model and with a simple quark-parton model.

Confirmation of the A2 splitting near threshold

Abstract The shape of the A 2 resonance has been measured in π p → pA 2 at 2.6 GeV/ c , i.e. near threshold, with A 2 produced at minimum momentum transfer. The results confirm, with a new method and instrument, the A 2 splitting found previously with the Jacobian-peak method.

The reaction p+p(↑) → π+ + d between 1.0 and 1.5 GeV/c

Abstract Polarizationdata for the reaction pp → π+d on polarized protons at 1.04, 1.13, 1.21, 1.37 and 1.45 GeV/c are presented. The coefficient characterizing the angular distribution of the polarization show an energy dependence similar to that of the total cross-section and are consistent with the view that N∗ ( 3 2 , 3 2 ) production dominates the reaction mechanism.

Correlations associated with particles produced at small angles in pp collisions at the CERN ISR

Abstract Data on correlations between momentum analysed protons, pions or K mesons, and charged particles produced in pp collisions at the CERN ISR are presented. The charged particles were detected in a ∼4π scintillation counter hodoscope. The pseudo-rapidity distributions are well described by production within the limits of cylindrical phase space, with negative kaons and antiprotons yielding narrower distributions than protons, pions and positive kaons. The azimuthal distributions show symmetry around the t-channel axis in the rest frame of the recoiling mass Mx in pp → aX (a = detected proton, pion, positive kaon).

Polarization in elastic antiproton-proton scattering between 0.9 and 2.5 GeV/c

Abstract Polarization and differential cross-section data are presented for elastic scattering of antiprotons on polarized protons at eight momenta between 0.9 and 2.5 GeV/ c . The data are fitted with a diffraction model.

Search for stable particles of charge 1 and mass deuteron mass

In a search for stable massive particles of charge q ⩾ 1 at the CERN ISR (√s = 53 GeV) no new particle in the mass range q × 2.4 GeV < m ≲ 30 GeV has been found among 3.1 × 107 recorded secondaries. At x = 2pL/√s = 0.21 and pT = 0.21 GeV/c the deuteron to π+ ratio is (1.3±0.2) × 10−4 and the antideuteron to π− ratio is (7.6±2.3) × 10−6. for (anti)tritons upper limits of (t/π+) < 5 × 10−7and (t/π−7) < 5 × 10−7 have been obtained.

Correlations associated with small angle protons produced in proton- proton collisions at 31 gev total energy

High energy inelastic protons with x = 2 pL/s12 > 0.99 observed in 15.3/15.3 GeV proton-proton collisions at the CERN ISR are accompanied by particles whose angular distribution is confined to a narrow cone in the opposite direction. In constrast, lower energy protons (0.72 < x < 0.84) are accompanied in addition, by particles emitted at larger angles. The ratio of the associated charged multiplicities is approximately 0.4.

Spectrum of charged non-strange bosons in the mass region 2.5–3.0 GeV

Abstract The CERN boson spectrometer shows significant enhancements in the spectrum of charged non-strange bosons near 2.6 GeV and 2.8 GeV mass values.

Polarization in elastic π−p scattering at 16 momenta between 865 and 2732 MeV/c

Polarization distributions and differential cross section data for elastic scattering of negative pions on protons between 865 and 2732 MeV/c are presented. They are compared with published phase-shift analyses.