Common lore suggests that N-color QCD with massive quarks has no useful order parameters that can be nontrivial at zero baryon density. However, such order parameters do exist when there are nf quark flavors with a common mass and d≡gcd(nf,N)>1. These theories have a Zd color-flavor center symmetry arising from intertwined color center transformations and cyclic flavor permutations. The symmetry realization depends on the temperature, baryon chemical potential, and value of nf/N, with implications for conformal window studies and dense quark matter.
Bibliographical noteFunding Information:
We are grateful to D. B. Kaplan, L. McLerran, S. Reddy, A. Roggero, M. Savage, and T. Schäfer for stimulating discussions. This work was supported, in part, by the U.S. Department of Energy via Awards No. DE-FG02-00ER-41132 (A. C.), No. DE-FG02-04ER41338 (S. S.), No. DE-SC0013036 (M. Ü.), No. DE-FG02-00ER41132 (M. W.), and No. DE-SC0011637 (L. Y.). L. Y. thanks the University of Regensburg and the Alexander von Humboldt foundation and S. S. thanks Los Alamos National Laboratory for their generous support and hospitality during completion of this work.
© 2017 American Physical Society.