TY - JOUR T1 - Photoassociation of spin polarized Chromium JF - Physical Review A Y1 - 2016 A1 - Jahn Rührig A1 - Tobias Bäuerle A1 - Paul S. Julienne A1 - Eite Tiesinga A1 - Tilman Pfau AB - We report the homonuclear photoassociation (PA) of ultracold 52Cr atoms in an optical dipole trap. This constitutes the first measurement of PA in an element with total electron spin S~>1. Although Cr, with its 7S3 ground and 7P4,3,2 excited states, is expected to have a complicated PA spectrum we show that a spin polarized cloud exhibits a remarkably simple PA spectrum when circularly polarized light is applied. Over a scan range of 20 GHz below the 7P3 asymptote we observe two distinct vibrational series each following a LeRoy-Bernstein law for a C3/R3 potential with excellent agreement. We determine the C3 coefficients of the Hund's case c) relativistic adiabatic potentials to be -1.83±0.02 a.u. and -1.46±0.01a.u.. Theoretical non-rotating Movre-Pichler calculations enable a first assignment of the series to Ω=6u and 5g potential energy curves. In a different set of experiments we disturb the selection rules by a transverse magnetic field which leads to additional PA series. VL - 93 U4 - 021406 UR - http://arxiv.org/abs/1512.04378 CP - 2 U5 - 10.1103/PhysRevA.93.021406 ER -