Three-nucleon Nuclei Research Articles

Microscopic description of diffractive deuteron breakup by 3He nuclei

A microscopic formalism for describing observed cross sections for deuteron breakup by three-nucleon nuclei was developed on the basis of the diffraction nuclear model. A general formula that describes the amplitude for the reaction d+3He->3He+p+n and which involves only one adjustable parameter was obtained by using expansions of the integrands involved in terms of a Gaussian basis. This formula was used to analyze experimental data on the exclusive cross sections for deuteron breakup by He-3 nuclei at the projectile energy of 89.4 MeV. The importance of employing, in calculations, a deuteron wave function that has a correct asymptotic behavior at large nucleon-nucleon distances was demonstrated.

ELECTRIC DIPOLE POLARIZABILITIES OF THE TRITON AND LAMBDA HYPERTRITON

A rigorous formalism for determining the electric dipole polarizability of a three-hadron bound complex in the case that the system has only one bound (ground) state has been elaborated. On its basis, by applying a model wave function that takes into account specific features of the structure of the three-body nuclei and using the known low-energy experimental data for the p–n, n–d, and Λ–d systems as input data, we have calculated the values of the electric dipole polarizabilities of the triton αE(3H ) and lambda hypertriton [Formula: see text]. We have obtained for the triton polarizability the value 0.23 fm3. It follows from our study that the polarizability of the lambda hypertriton is close to 3 fm3exceeding the polarizabilities of the ordinary three-nucleon nuclei by an order of magnitude.

Cumulative production of three-nucleon nuclei in 16Op collisions at a momentum of 3.25 GeV/c per nucleon

The production of cumulative three-nucleon nuclei (3H and 3He) in 16Op collisions at a momentum of 3.25 GeV/c per nucleon were studied for the first time under conditions of 4π geometry. The slope parameter of the cross section for the production of cumulative three-nucleon nuclei was determined, and new data on correlations of the yields of A = 3 cumulative nuclei, charged particles, and fragments in 16Op interactions are reported. The properties of cumulative and noncumulative events were found to be substantially different, and evidence for the presence of a common universal feature in the mechanisms for the cumulative production of hadrons and light nuclear fragments was obtained.

Doublet coulomb-nuclear scattering length and other parameters of the effective-range function for proton-deuteron scattering from an analysis of present-day data

Parameters of the effective-range function K(k2) having a pole are found from the results that were obtained by calculating the S-wave phase shifts for doublet proton-deuteron scattering and the binding energies of three-nucleon nuclei on the basis of Faddeev equations and within the N/D method and which are known from the literature. The convergence of the expansion of K(k2) in powers of the momentum is studied. The energy of the proton-deuteron resonance corresponding to the virtual triton state is calculated.

Effect of the structure of He3 and H3 on their cross sections for total electrodisintegration

Angular distributions of nucleons produced in the total electrodisintegration of three-nucleon nuclei are calculated. Both K-harmonic and model Gaussian functions are used as nuclear wave functions in the calculation. It is shown that it is possible to obtain agreement between the calculated and experimental distributions by using the K-harmonic wave functions if states of mixed symmetry and final-state interactions are taken into account.

Role of interaction in final state accompanying total electrodisintegration of three-nucleon nuclei

The distributions of electrons by angle and energy are calculated for the inelastic scattering by three-nucleon nuclei accompanied by their total disintegration, taking into account the interaction in the final state and the contribution of the intermediate-symmetry functions in the ground state of the nuclei. The high level of sensitivity of the distributions to the interaction between the reaction products and the need to take into account the interaction in order to match the calculations with experimental scattered-electron spectra are demonstrated.

Angular distribution of electrons scattered at three-nucleon nuclei, splitting them into a nucleon and a deuteron

The angular distributions of the electrons undergoing inelastic scattering at He3 and H3 nuclei (accompanied by the two-particle splitting of the nuclei) are derived, with and without allowing for the interaction between the nucleon and deuteron so formed. Interaction in the final state has a major effect on the calculated relationships, and due allowance for this interaction improves agreement between theory and experiment in relation to the calculated cross sections.