arXiv:1001.2809v1 [physics.atom-ph] 16 Jan 2010 PACS numbers: Dipolar collisions of polar molecules in the quantum regime K.-K. Ni, 1 ∗ S. Ospelkaus, 1 ∗ D. Wang, 1 G. Qu´em´ener, 1 B. Neyenhuis, 1 M. H. G. de Miranda, 1 J. L. Bohn, 1 J. Ye, 1 † D. S. Jin 1 † $^{1}$JILA, NIST and University of Colorado, Department of Physics, University of Colorado Boulder, CO 80309-0440, USA $^{∗}$These authors contributed equally to this work; $^{†}$To whom correspondence should be addressed; E-mail: Ye@jila.colorado.edu; Jin@jilau1.colorado.edu 1