  We analyse a narrow Feshbach resonance with ultra-cold chromium atoms
colliding in d-wave. The resonance is made possible by dipole-dipole
interactions, which couple an incoming $l=2$ collision channel with a bound
molecular state with $l=0$. We find that three-body losses associated to this
resonance increase with temperature, and that the loss feature width as a
function of magnetic field also increases linearly with temperature. The
analysis of our experimental data shows that the Feshbach coupling is small
compared both to the temperature and to the density limited lifetime of the
resonant bound molecular state. One consequence is that the three body losse
rate is proportionnal to the square of the number of atoms, and that we can
directly relate the amplitude of the losses to the Feshbach coupling parameter.
We compare our measurement to a calculation of the coupling between the
collisionnal channel and the molecular bound state by dipole-dipole
interactions, and find a good agreement, with no adjustable parameter. An
analysis of the loss lineshape is also performed, which enables to precisely
measure the position of the resonance.
