Weakly Bound States Of The He-He-⁴⁴Ca Triatomic System

The search for weakly bound states of quantum few-body systems is becoming one of the hot issues in many physical branches.Theoretical discussions on micro-few-body systems help us to deeply understand the ultra cold atomic collisions?Bose-Einstein condensate,and lay the foundation for analyzing more complicated principles of many-body systems.Moreover,some unusual quantum properties may be found in weakly bound three-body systems,such as the halo states(or Borromean states)or Efimov states.In this thesis,we investigated the existence of three-atom molecule He2 44Ca using hyperspherical coordinates in the case of L = 0.First,we adopted the most accurate potential model between each pair of atoms,then the Schrodinger equation for the three-atom molecule is solved using the B-Spline method within the adiabatic hyperspherical approximation.Therefore,hyperspherical potential curves and orthogonal channel functions for each three-atom systems were obtained.For the triatomic systems:4He4He44Ca,4He3He44Ca and 3He3He44Ca,the upper bounds of the ground states binding energies are-5.5275K,-4.5834K and-4.1823K respectively;yet the lower bounds of the ground states binding energies are-7.0517K,-5.9579K and-5.7287K respectively.There don't exist halo states or Efimov states for this complex.