Long-range states in excited ultracold³He*–⁴He* dimers

Abstract

Abstract. Long-range bound states of the excited heteronuclear 3 He * -4 He * system that dissociate to either 3 He(1s2s 3 S 1 ) + 4 He(1s2p 3 P j ) or 3 He(1s2p 3 P j ) + 4 He(1s2s 3 S 1 ), where j = 0, 1, 2, are investigated using both single-channel and multichannel calculations in order to analyse the effects of Coriolis and non-adiabatic couplings. The multichannel calculations predict two groups of resonances above the lowest asymptotic energy. One of these groups dissociates to an atomic pair with the 2p excitation on the fermionic atom and the other dissociates to two asymptotes which correspond to the 2p excitation on either atom. Many of these resonances could be identified with levels in the single-channel calculation although the differences in energies were large. The total parity was found to have a significant influence on the ability to make these identifications. No purely bound states were found, although several resonances with line widths smaller than 1 MHz were obtained.

Ultracold homonuclear and heteronuclear collisions in metastable helium

“…(43) This relationship simplifies as the total angular momentum transition matrix elements T a ′ a (E) and scattering matrix elements S a ′ a (E) = δ a ′ ,a −T a ′ a (E) extracted from the asymptotic solutions of (10) are diagonal in J and independent of M J , allowing the notation T J Γ ′ f ′ l ′ ,Γf l and S J Γ ′ f ′ l ′ ,Γf l . For the homonuclear 3-3 and 4-4 systems, the matrix elements T a ′ a and S a ′ a are understood to be in the symmetrized basis (19) whereas, for the heteronuclear 3-4 system, unsymmetrized states are used.…”

“…We note that these states | (S 1 ) A , (S 2 ) B , S, M S , w are also eigenstates of PS and are gerade (ungerade) for even (odd) S. Hereafter we shall omit the label w on the potentials. The matrix elements a ′ | Ĥel |a are constructed from the matrix elements [19] (see Appendix A)…”

“…For the homonuclear 3-3 and 4-4 systems, the matrix elements T a ′ a and S a ′ a are understood to be in the symmetrized basis (19) whereas, for the heteronuclear 3-4 system, unsymmetrized states are used.…”