title: Long-range interactions between polar bialkali ground-state molecules in arbitrary vibrational levels.
abstract: We have calculated the isotropic C6 coefficients characterizing the long-range van der Waals interaction between two identical heteronuclear alkali-metal diatomic molecules in the same arbitrary vibrational level of their ground electronic state X(1)Σ(+). We consider the ten species made up of (7)Li, (23)Na, (39)K, (87)Rb, and (133)Cs. Following our previous work [Lepers et al., Phys. Rev. A 88, 032709 (2013)], we use the sum-over-state formula inherent to the second-order perturbation theory, composed of the contributions from the transitions within the ground state levels, from the transition between ground-state and excited state levels, and from a crossed term. These calculations involve a combination of experimental and quantum-chemical data for potential energy curves and transition dipole moments. We also investigate the case where the two molecules are in different vibrational levels and we show that the Moelwyn-Hughes approximation is valid provided that it is applied for each of the three contributions to the sum-over-state formula. Our results are particularly relevant in the context of inelastic and reactive collisions between ultracold bialkali molecules in deeply bound or in Feshbach levels.
authors.affiliation: Laboratoire Aimé Cotton, CNRS/Université Paris-Sud/ENS-Cachan, Bât. 505, Campus d'Orsay, 91405 Orsay, France.
authors.forename: R
authors.initials: R
authors.lastname: Vexiau
authors.affiliation: Laboratoire Aimé Cotton, CNRS/Université Paris-Sud/ENS-Cachan, Bât. 505, Campus d'Orsay, 91405 Orsay, France.
authors.forename: M
authors.initials: M
authors.lastname: Lepers
authors.affiliation: Laboratoire Aimé Cotton, CNRS/Université Paris-Sud/ENS-Cachan, Bât. 505, Campus d'Orsay, 91405 Orsay, France.
authors.forename: M
authors.initials: M
authors.lastname: Aymar
authors.affiliation: Laboratoire Aimé Cotton, CNRS/Université Paris-Sud/ENS-Cachan, Bât. 505, Campus d'Orsay, 91405 Orsay, France.
authors.forename: N
authors.initials: N
authors.lastname: Bouloufa-Maafa
authors.affiliation: Laboratoire Aimé Cotton, CNRS/Université Paris-Sud/ENS-Cachan, Bât. 505, Campus d'Orsay, 91405 Orsay, France.
authors.forename: O
authors.initials: O
authors.lastname: Dulieu