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

Abstract

The behaviour of the topological susceptibility \chi 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 \chi drops abruptly at a critical chemical potential \mu_c, 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 \mu_c. At a value \mu_s of the chemical potential, called saturation point, which in our case satisfies \mu_s > \mu_c, Pauli blocking supervenes and consequently the theory becomes quenched.

Comments: Latex file, 28 pages, 6 Figures, revised version with further study of Pauli blocking, phase diagram, physical units and the HMD algorithm. A few misprints corrected. Some references added