PHASE STRUCTURE OF FOUR FLAVOUR QCD IN THE T µ PLANE FROM A NEW METHOD FOR SIMULATIONS OF LATTICE GAUGE THEORIES AT NON-ZERO BARYON DENSITY

VICENTE AZCOITIDepartamento de Fisica Teorica, Universidad de ZaragozaPedro Cerbuna 12, E-50009 Zaragoza, SpainGIUSEPPE DI CARLOINFN, Laboratori Nazionali del Gran Sasso I-67010 Assergi (L’Aquila), ItalyANGELO GALANTEDipartimento di Fisica dell’ Universita’ di L’Aquila I-67100 L’Aquila, Italy andINFN, Laboratori Nazionali del Gran Sasso I-67010 Assergi (L’Aquila), ItalyVICTOR LALIENADepartamento de Fisica Teorica, Universidad de ZaragozaPedro Cerbuna 12, E-50009 Zaragoza, SpainWe review a method for numerical simulations of lattice gauge theories at non-zerobaryonic chemical potential we recently proposed. We first report on a test of the methodusing a solvable model and then present results for the phase structure of four flavourQCD. For the first time the region of chemical potential up to 1.4 T