Fractional Superfluid Vortices and Worldsheet Wess--Zumino--Witten Models in Two-Color QCD and $Sp(2N)$ Gauge Theories
We study superfluid vortices in two-color QCD and more general pseudoreal gauge theories with even flavor number $N_f=2m$ at finite baryon density. The antisymmetric diquark condensate admits fractional minimal vortices with baryon-phase winding $\nu=1/m$, corresponding to $1/m$ of the conventional circulation quantum,...