Particle theory

Abstract:

The large N limit of SU(N) gauge theories in 3+1 dimensions is investigated on the lattice by extrapolating results obtained for 2 ≤ N ≤ 5. A numerical determination of the masses of the lowest-lying glueball states and of the topological susceptibility in the limit N → ∞ is provided. Ratios of the tensions of stable κ-strings over the tension of the fundamental string are investigated in various regimes and the results are compared with expectations based on several scenarios - in particular MQCD and Casimir scaling. While not conclusive at zero temperature in D=3+1, in the other cases investigated our data seem to favour the latter.