M. Kawasaki

Observation of double-hypernuclei and Λ-Λ interaction

Abstract A hybrid-emulsion experiment has been carried out at KEK-PS to study S = −2 nuclei. With the analysis of about 35% of total emulsion, we have successfully found three events of sequential weak decay of a double-hypernucleus. The results of these E373 events are summarized together with those of past experiments. The first experimental study of the branching ratios of weak decay modes of double-hypernuclei has been performed.

the elastic pp differential cross section measurements at the CERN SppS and the real part of the scattering amplitude

Abstract The experimental data of the p p differential cross section in the energy range ∝s = 541–546 GeV at the CERN S p p S including the recent precise UA4/2 experiment in the Coulomb interference region are analyzed to obtain information on the real part of the scattering amplitude at the whole region of the momentum transfer of the experimental data points. We make a fit to the experimental data by using the real part of the scattering amplitude given by the derivative dispersion relation (DDR). We obtrained ϱ = 0.120−0.003+0.017 for the ratio of the real part to the imaginary part of the forward scattering amplitude.

MOMENTUM-TRANSFER STRUCTURE OF POMERON AT ACCELERATOR ENERGIES

A representation of Pomeron amplitude derived asymptotically in the framework of the geometrical diffraction picture is shown to be consistent with the gross feature of the experimental data of the differential cross-section of pp and

THE FORWARD PEAK OF ELASTIC HARDON-HADRON SCATTERING AND UNITARITY BOUNDS FOR THE DIFFERENTIAL CROSS-SECTION

\bar{p}p

BOUNDS FOR THE DIFFERENTIAL CROSS-SECTION OF ELASTIC HADRON SCATTERING

scattering in the low energy region

Evaluation of elastic N. Delta. scattering amplitude from inelastic pp yields N. Delta. amplitude

\sqrt{s}=20\hbox{--}1800~{\rm GeV}

Observation of a 6 ∧∧ He double hypernucleus

over a wide range of momentum transfer. It is found that the most peripheral part of the diffraction interaction is characterized by a mass parameter of 0.4–0.5 GeV indicating the dominance of the two-pion states.

Break structure of forward peaks of elastic pp and p-barp scattering at high energies.

Unitarity bounds for the differential cross-section of high-energy elastic hadron-hadron scattering are obtained under the constraints of fixed total cross-section σt, elasticity x, real part to imaginary part ratio ρ of the forward scattering amplitude, and forward slope b by assuming a finite interaction range. The obtained upper bound has an observed curvature structure at small momentum transfers and is nearly saturated by the experimental data of pp and scattering at −t=0−0.3 (GeV/c)2 in the energy region , if we take the interaction radius scaled as .

Dip-bump structure of the elastic hadron-hadron differential cross section

We have examined the external properties of the differential cross-section of elastic hadron scattering. General criteria for the maximum, minimum and saddle points have been obtained. It is found that the extremum given by Arushanov previously as the lower bound for the backward cross-section will become a saddle point at high energies, contrary to his assertion.

Generalized geometrical scaling behavior of elastic hadron-hadron scattering amplitudes at high energies.

In the dibaryon energy region we have evaluated the NΔ→NΔ (5S2) partial-wave S-matrix element from recently obtained pp→NΔ transition amplitude by combining with the information on pp→pp, pp→πd, and πd→πd scattering amplitudes in the three-channel approximation. One of the two solutions allowed by the unitarity shows an anticlockwise rotating behavior.