a decade [@HSNature; @HSglass; @MCTtheoryHS; @MCTreview]. The phase behaviour of a system of $N$ hard-spheres of radius $R$ in volume $V$ is determined by a single variable, the density or volume fraction $\phi=(4/3)\pi
R^3N/V$. Increasing $\phi$ drives the system from a stable fluid to a fluid-crystal coexistence, and then a fully crystallized phase [@HSNature], which should be the thermodynamically favorable phase up to $\phi = \pi/3\sqrt{2} \approx 0.74$. However, at $\phi\geq
\phi_g\approx0.58$, hard spheres fail to crystallize [@HSNature; @HSglass]. This is usually interpreted as a glass transition due to the caging of particles by each other. The most successful theoretical account given of this transition to date is from mode coupling theory (MCT) [@MCTtheoryHS; @HSglass]. Within this framework, the coupling between different density fluctuation modes drives the system into a dynamically arrested state [@MCTreview].

More recently, the focus of attention has moved on to hard spheres with a short-range attraction. Besides being a good model for understanding the fundamentals of the glass transition, such ‘sticky hard spheres’ are also ubiquitous in applications. Attraction in hard-spheres can be realized experimentally by adding non-adsorbing polymers to colloids. The center of mass of a polymer coil of radius of gyration $r_g$ is excluded 