Behaviour of the topological susceptibility in two colour QCD across the finite density transition.

The behaviour of the topological susceptibility χ in QCD with two colours and 8 flavours of quarks is studied at nonzero temperature on the lattice across the finite density transition. It is shown that the signal of χ drops abruptly at a critical chemical potential μc, much as it happens at the finite temperature and zero density transition. The Polyakov loop and the chiral condensate undergo their transitions at the same critical value μc. At a value μs of the chemical potential, called saturation point, which in our case satisfies μs >μc, Pauli blocking supervenes and consequently the theory becomes quenched.