Static magnetic susceptibility in finite-density SU (2) lattice gauge theory

We study static magnetic susceptibility chi(T,mu) in SU(2) lattice gauge theory with N-f = 2 light flavours of dynamical fermions at finite chemical potential mu. Using linear response theory we find that SU(2) gauge theory exhibits paramagnetic behavior in both the high-temperature deconfined regime and the low-temperature confining regime. Paramagnetic response becomes stronger at higher temperatures and larger values of the chemical potential. For our range of temperatures 0.727 <= T/ T-c <= 2.67, the first coefficient of the expansion of chi (T, mu) in even powers of mu/T around mu = 0 is close to that of free quarks and lies in the range (2,..., 5) center dot 10(-3). The strongest paramagnetic response is found in the diquark condensation phase at mu > m pi/2.

Automated summary

In SU(2) lattice gauge theory with two light flavours of dynamical fermions at finite chemical potential, we observe paramagnetic behavior in both high-temperature deconfined regime and low-temperature confining regime, with paramagnetic response becoming stronger at higher temperatures and larger chemical potentials. The first coefficient of the expansion of magnetic susceptibility in even powers of chemical potential around zero is close to that of free quarks and the strongest paramagnetic response is found in the diquark condensation phase at mu > m pi/2.