  We study inelastic collisions in a pure, trapped sample of Feshbach molecules
made of bosonic cesium atoms in the quantum halo regime. We measure the
relaxation rate coefficient for decay to lower-lying molecular states and study
the dependence on scattering length and temperature. We identify a pronounced
loss minimum with varying scattering length along with a further suppression of
loss with decreasing temperature. Our observations provide insight into the
physics of a few-body quantum system that consists of four identical bosons at
large values of the two-body scattering length.
