V.N. Fetisov

Supermultiplet structure and decay properties of hypernuclear 1+ resonances in Λ6Li

Abstract The excitation function for the 0 ℏω and 1 ℏω levels of Λ6Li, populated in the (K−, π−) reaction at ϑ π= 0°, is calculated in the framework of the translationally invariant shell model. One-baryon and cluster widths for the decay of resonance hypernuclear states are estimated. The decay properties of those states are shown to be essentially given by the Young tableaux selection rules. Very good agreement with recent experimental data at pK = 790 MeV/c at CERN is achieved. The decay of Λ 6 Li ∗ into exicted Λ 4 He ∗ ( Λ 4 H ∗ ) with subsequent hypernuclear γ-emission is discussed as well.

Are the solar-neutrino experiments suggestive of the existence of a resonance in the 3He + 3He system?

Abstract The possibility of the existence of a resonance in the 3 He + 3 He system, which may be important for explaining the solar-neutrino experiments, is discussed.

On the possibility of hypernucleus production by high energy protons and electrons

Abstract Methods of hypernucleus production by high energy particles are suggested. It is shown that the estimated cross sections are measurable with a modern experimental technique.

On nucleon decays of hypernuclear resonances — Population of bound hypernuclear levels

Abstract Hypernuclear resonances excited in ( K − ,π 0 ) reactions decay also via the nucleon channel and the low lying part of hypernuclear spectra is thus populated. The analysis — quantitative for A = 14- suggests to measure neutron line spectra and hypernuclear γ-quanta. The novel spectroscopy should reveal new information on the structure (deviations from the weak coupling scheme), on the NΛ effective interaction (its possible long-rangedness) and on decay mechanisms.

Excitation and structure of hypernuclear resonances in (K−,π¯0)-reactions on 1p-shell nuclei

The available experimental data on the excitation functions (EF) of the 1p-shellΛ-hy-pernuclei in (K−, π−) reactions atθπ = 0° has been analysed in terms of shell model and weak coupling scheme. It is substantiated by the experimental data on the neutron spectroscopic factors and on the fragmentation of nuclear hole excitations. The pronounced nuclear spectroscopic characteristics in the hypernuclear spectra are indicative of a weak coupling ofΛ-hyperon with nuclear subsystem. The analysis has made it possible to determine the difference is single-particle energies ofΛ-hyperon in the 1p- and 1s-states and to obtain additional evidence for the smallness of theΛ-nucleus spin-orbit interaction. The resonance structure of EF of hypernuclei, which were not studied in (K−,π0−) reactions, is predicted. The interrelated aspects of the studies of the (K−,π0−), (K−,π0− β′), and (K−, π+) reactions which are of interest to spectroscopy ofΛ-andΣ-hypernuclei are discussed.

Influence ofp-shell nuclei structure on the formation of hypernuclear resonances

In the translationally invariant shell model the supermultiplet structure of the 1ħω states ofp-shell hypernuclei is studied. Fragmentation of the strangeness analogue state is discussed and the spectroscopic amplitudes for all decay channels are estimated.

Dipole sum rule for three-particle nuclei with the Gammel-Brueckner potential

Abstract The integrated E1 photoabsorption cross section has been calculated for three-particle nuclei with the Gammel-Brueckner potential. The insensitivity of the theoretical value σ 0 to the form of realistic potentials is discussed.

Polarization phenomena in the direct and inverse photonuclear reactions with tritium and helium - 3

Abstract The polarization phenomena in the reactions γ + 3 H ( 3 He ) ⇌ n ( p ) + d with polarized beams of γ rays and nucleons are discussed.