Phenomenological analysis of breakup of 9Be nuclei into two α-particles and neutron in peripheral interactions with emulsion nuclei

Abstract

Phenomenological Monte Carlo model of peripheral interactions of 9Be nuclei with emulsion nuclei at [Formula: see text][Formula: see text]GeV with formation of an excited 9Be* nucleus and its subsequent breakup, either directly or through formation of an intermediate 8Be nucleus, into two [Formula: see text]-particles and a neutron was constructed. A comparative analysis of the experimental data on angular correlations and momentum spectra of [Formula: see text]-particles, coming from a breakup event, with the Monte Carlo model calculations was made. The constructed Monte Carlo model described quite satisfactory the total momentum and transverse momentum distributions of [Formula: see text]-particles and the distribution of angles between the total momentum (as well as transverse momentum) vectors of two [Formula: see text]-particles in 9Be* nucleus breakup events in experiment. For the first time, the total momentum and transverse momentum distributions of neutrons, accompanying two [Formula: see text]-particles from 9Be* decay, in peripheral interactions of 9Be nuclei with emulsion nuclei were reconstructed using the Monte Carlo model.

Study of continuum excitation by light weakly bound projectiles on proton target

“…In the last step, having determined the momentum vector of the excited 6 Li nucleus (P,θ), the momentum vectors of the breakup fragments are transformed from the 6 Li * rest frame to the laboratory one, by imposing a Galilean transformation followed by the appropriate rotation [1,9]. A comparison between the experimental and simulated coincidence spectra is presented in Figure 1.…”

Ελαστική σκέδαση και μηχανισμοί αντιδράσεων κοντά στο φράγμα Coulomb για το σύστημα 7Be+28Si

“…The α particle and one of the protons are emitted with randomly specified energies and momenta and the third fragment acquires energy and momentum fulfiling the conservations laws of energy and momentum at the rest frame of 6 Be. In the final step, following the prescription of Olimov et al [159], by applying a Galilean transformation and an axes rotation, the alpha energy spectra from the rest frame of 6 Be are transformed to the laboratory frame. The same or similar method was followed for the rest of the direct processes and the final energy spectrum was obtained by summing the four energy spectra normalized to the calculated cross sections.…”

“…Events with the same angle or with an angle inside an angular range corresponding to a particular vertical strip of each EXPADES detector (Δθ∼ 2 o ) are summed up both for the elastic scattering on the silicon target as well as for the elastic scattering on a lead target used for the determination of the solid angles, and the differential cross sections are deduced via the following equation: 3. In this third step we combine information from the first two steps, that is the momentum of 6 Be in the laboratory frame and the momenta of the fragments in the rest frame of 6 Be, for transforming the momentum components from system K to K according to the prescription of Olimov et al [159]. In this model the Z axis in the K system, is considered at the same direction as P lab (momentum of the 6 Be nucleus in the laboratory system).…”