title: No-go theorem for critical phenomena in large-N(c) QCD.
abstract: We derive some rigorous results on the chiral phase transition in QCD and QCD-like theories with a large number of colors, N(c), based on the QCD inequalities and the large-N(c) orbifold equivalence. We show that critical phenomena and associated soft modes are forbidden in flavor-symmetric QCD at finite temperature T and finite but not so large quark chemical potential μ for any nonzero quark mass. In particular, the critical point in QCD at a finite baryon chemical potential μ(B)=N(c)μ is ruled out, if the coordinate (T, μ) is outside the pion condensed phase in the corresponding phase diagram of QCD at a finite isospin chemical potential μ(I)=2μ.
authors.affiliation: Mathematical Physics Laboratory, RIKEN Nishina Center, Saitama 351-0198, Japan.
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Hidaka
authors.forename: Naoki
authors.initials: N
authors.lastname: Yamamoto