Phase structure of lattice QCD for general number of flavors
Abstract
We investigate the phase structure of lattice QCD for the general number of flavors in the parameter space of gauge coupling constant and quark mass, employing the oneplaquette gauge action and the standard Wilson quark action. Performing a series of simulations for the number of flavors N_{F}=6 360 with degeneratemass quarks, we find that when N_{F}⩾7 there is a line of a bulk first order phase transition between the confined phase and a deconfined phase at a finite current quark mass in the strong coupling region and the intermediate coupling region. The massless quark line exists only in the deconfined phase. Based on these numerical results in the strong coupling limit and in the intermediate coupling region, we propose the following phase structure, depending on the number of flavors whose masses are less than Λ_{d} which is the physical scale characterizing the phase transition in the weak coupling region: When N_{F}⩾17, there is only a trivial IR fixed point and therefore the theory in the continuum limit is free. On the other hand, when 16⩾N_{F}⩾7, there is a nontrivial IR fixed point and therefore the theory is nontrivial with anomalous dimensions, however, without quark confinement. Theories which satisfy both quark confinement and spontaneous chiral symmetry breaking in the continuum limit exist only for N_{F}⩽6.
 Publication:

Physical Review D
 Pub Date:
 January 2004
 DOI:
 10.1103/PhysRevD.69.014507
 arXiv:
 arXiv:heplat/0309159
 Bibcode:
 2004PhRvD..69a4507I
 Keywords:

 12.38.Gc;
 11.15.Ha;
 12.38.Aw;
 Lattice QCD calculations;
 Lattice gauge theory;
 General properties of QCD;
 High Energy Physics  Lattice;
 High Energy Physics  Phenomenology
 EPrint:
 RevTeX, 20 pages, 43 PS figures