A (diatomic) shape resonance is a metastable state of a pair of colliding atoms quasi-
bound by the centrifugal barrier imposed by the angular momentum involved in the 
collision. The temporary trapping of the atoms’ scattering wavefunction corresponds to an
enhanced atom pair density at low interatomic separations. This leads to larger overlap 
of the wavefunctions involved in a molecule formation process such as photoassociation, 
rendering the process more efficient. However, for an ensemble of atoms, the atom pair 
density will only be enhanced if the energy of the resonance comes close to the 
temperature of the atomic ensemble. Herein we explore the possibility of controlling the 
energy of a shape resonance by shifting it toward the temperature of atoms confined in a 
trap. The shifts are imparted by the interaction of non-resonant light with the 
anisotropic polarizability of the atom pair, which affects both the centrifugal barrier 
and the pair’s rotational and vibrational levels. We find that at laser intensities of up
to 5× 10? W/cm² the pair density is increased by one order of magnitude for 87Rb atoms at 
100 µK and by two orders of magnitude for 88Sr atoms at 20 µK.