$${}^{5}$$He($${}^{3}$$He,$${}^{4}$$He)$${}^{4}$$He as a three-body reaction via a continuum resonance in the n+$${}^{4}$$He system

The $${}^{5}$$ 5 He($${}^{3}$$ 3 He,$${}^{4}$$ 4 He)$${}^{4}$$ 4 He reaction involving the unstable $${}^{5}$$ 5 He nucleus is a possible process in primordial nucleosynthesis to convert $${}^{3}$$ 3 He into $${}^{4}$$ 4 He in a neutron transfer reaction. Since experimental data for the reaction cross section are not available, a theoretical prediction is needed to estimate the relevance of this process in comparison to other reactions, e.g., $${}^{3}$$ 3 He($${}^{2}$$ 2 H,p)$${}^{4}$$ 4 He or $${}^{3}$$ 3 H($${}^{2}$$ 2 H,n)$${}^{4}$$ 4 He. In this work the cross section and the Maxwellian-averaged transition rate of the $${}^{5}$$ 5 He($${}^{3}$$ 3 He,$${}^{4}$$ 4 He)$${}^{4}$$ 4 He reaction are calculated using a post-form distorted-wave Born approximation in a simple cluster model. For that purpose the reaction is treated as a genuine process with three particles, $$\text{ n }+{}^{4}\text{ He }+{}^{3}\text{ He }$$ n + 4 He + 3 He , in the entrance channel proceeding through the $$3/2^{-}$$ 3 / 2 - resonance in the $$n-{}^{4}$$ n - 4 He scattering continuum.

Vibrational Quenching of Weakly Bound Cold Molecular Ions Immersed in Their Parent Gas

Hybrid ion–atom systems provide an excellent platform for studies of state-resolved quantum chemistry at low temperatures, where quantum effects may be prevalent. Here we study theoretically the process of vibrational relaxation of an initially weakly bound molecular ion due to collisions with the background gas atoms. We show that this inelastic process is governed by the universal long-range part of the interaction potential, which allows for using simplified model potentials applicable to multiple atomic species. The product distribution after the collision can be estimated by making use of the distorted wave Born approximation. We find that the inelastic collisions lead predominantly to small changes in the binding energy of the molecular ion.

Simplistic distorted-wave Born approximation interpretation of the 11Li(p,t)9Li reaction

The reaction [Formula: see text]Li([Formula: see text])9Li(gs) at an incident energy of 4.3[Formula: see text]MeV is interpreted in terms of a simplistic distorted-wave Born approximation, which assumes simultaneous transfer of the halo neutrons. The halo neutrons involved in the reaction is treated as either a di-neutron cluster or individual entities. Either of these approaches appears to be a good approximation of the reaction mechanism, as would be expected from earlier studies. The dominant contribution to the yield of the reaction comes from the known (2[Formula: see text])2 neutron structure component of the ground state of [Formula: see text]Li. Furthermore, the cross-section angular distribution seems to be relatively insensitive to the fact that [Formula: see text]Li has an anomalously large radius due to its Borromean halo properties. Significantly this simple treatment of the reaction is in much better agreement with the experimental angular distribution than previous sophisticated calculations. The relevance and limitations of a more advanced theoretical treatment which includes coupled channel and sequential transfer are discussed in the context of the present results.

Measurement and analysis of 10B +12C elastic scattering at energy of 41.3MeV

Angular distribution of the [Formula: see text] elastic scattering was measured at [Formula: see text][Formula: see text]MeV. Experimental data showed a significant increase in differential cross-sections at backward angles. The optical model with phenomenological potentials reproduces well the experimental cross-sections in the region of the angles of the forward hemisphere, but is not able to explain the increase in cross-sections at large angles. The distorted wave Born approximation method was used to reproduce the experimental data at large angles [Formula: see text] by taking into consideration a deuteron transfer. Spectroscopic amplitude has been extracted for the configuration [Formula: see text]C[Formula: see text]B + [Formula: see text] from the analysis.