Static magnetic susceptibility in finite-density $$SU\left( 2\right) $$ S U 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 $$0.727 \le T/T_c \le 2.67$$ , the first coefficient of the expansion of $$\chi \left( T, \mu \right) $$ in even powers of $$\mu /T$$ around $$\mu =0$$ is close to that of free quarks and lies in the range $$(2, \ldots , 5) \cdot 10^{-3}$$ . The strongest paramagnetic response is found in the diquark condensation phase at $$\mu >m\pi /2$$ .