HE 0557−4840: Ultra–Metal‐Poor and Carbon‐Rich

Autoionization of He and Autodetachment of He- following Bombardment by H+, H2+, He+, and He Atoms

Calculations of the binding energies of weakly bound He–He–H, He–He–H− and He–H–H molecules

We searched for the existence of weakly bound He–He–H, He–He–H− and He–H– H molecules where the binding energies are expected to be of the order of degrees Kelvin. By employing the best empirical interaction between each pair of particles, we solved the Schrödinger equation for the triatomic systems using hyperspherical coordinates in the adiabatic approximation. We found no bound states for 4H...

Stability of (3)He(2)(4)He(n) and (3)He(3)(4)He(n) L=0 clusters.

We have studied the stability of mixed (3)He/(4)He clusters in L=0 states by the diffusion Monte Carlo method, employing the Tang-Toennies-Yiu He-He potential. The clusters (3)He(4)He(N) and (3)He(2)(4)He(N) are stable for N>1. The lighter atoms tend to move to the surface of the cluster. The minimum number of 4He atoms able to bind three 3He atoms in a L=0 state is nine. Two of three fermionic...

The Evolution of 3 He , 4 He and D in

In this work we present the predictions of a modified version of the “two-infall model” (Chiappini et al. 1997) for the evolution of He, He and D in the Galaxy, as well as their distributions along the Galactic disk. In particular, we show that when allowing for extra-mixing process in low mass stars (M< 2.5 M⊙), as predicted by Charbonnel and do Nascimento (1998), a long standing problem in ch...

Structure and energetics of mixed 4 He - 3 He drops

Using a finite-range density functional, we have investigated the energetics and structural features of mixed helium clusters. The possibility of doping the cluster with a molecule of sulfur hexafluoride is also considered. It is seen that the repulsion introduced by the impurity strongly modifies the properties of the smallest drops. Although only a qualitative comparison is possible, the gros...