A Spectroscopic Determination of Scattering Lengths for Sodium Atom Collisions.
We report a preliminary value for the zero magnetic field Na2S(f= 1,m= - 1) + Na2S(f= 1,m= - 1) scattering length,a1,-1. This parameter describes the low-energy elastic two-body processes in a dilute gas of composite bosons and determines, to a large extent, the macroscopic wavefunction of a Bose condensate in a trap. Our scattering length is obtained from photoassociative spectroscopy with samples of uncondensed atoms. The temperature of the atoms is sufficiently low that contributions from the three lowest partial waves dominate the spectrum. The observed lineshapes for the purely long-range [Formula: see text] molecular state enable us to establish key features of the ground state scattering wavefunction. The fortuitous occurrence of ap-wave node near the deepest point (Re= 72a0) of the [Formula: see text] potential curve is instrumental in determininga1,-1= (52 ± 5)a0anda2,2= (85 ± 3)a0, where the latter is for a collision of two Na2S(f= 2,m= 2) atoms.
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001.
Eite
E
Tiesinga
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001.
Carl J
CJ
Williams
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001.
Paul S
PS
Julienne
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001.
Kevin M
KM
Jones
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001.
Paul D
PD
Lett
National Institute of Standards and Technology, Gaithersburg, MD 20899-0001.
William D
WD
Phillips
laser cooling; photoassociation spectroscopy; scattering length; spectral line shapes; ultracold sodium atom collisions