Propagators and phase structure ofNf=2andNf=2+

Abstract

We investigate the phase structure of QCD at finite temperature and chemical potential by solving a coupled set of truncated Dyson-Schwinger equations for the quark and gluon propagator. In contrast to previous calculations we take into account the full back-reaction of the quarks onto the Yang-Mills sector and we include the effects of strange quarks. We discuss the resulting thermal mass of the unquenched gluon propagator and extract order parameters for the chiral and deconfinement transition from the quarks. Our result for the temperature dependence of the quark condensate at zero chemical potential agrees well with corresponding lattice calculations. We determine the phase diagram at finite chemical potential and find a potential critical endpoint at (mu_q,T) = (190,100) MeV.Comment: 11 pages, 9 figures, 1 tabl

Phase diagram and thermal properties of strong-interaction matter

“…4, top panels; and the computed ratio µ χ E /T χ E = 0.87 is commensurate with those in Refs. [29,[66][67][68]. The chiral crossover becomes a first-order transition at CEP χ : the Nambu and Wigner phases coexist, with the Nambu phase dominant below the transition locus and the Wigner phase dominant otherwise.…”

Baryons as relativistic three-quark bound states

“…Exploratory lattice results are available in the quenched approximation [223], with unquenched updates under way. In the DSE framework the quark-gluon vertex has been tackled with three different strategies: (i) nonperturbative ansätze for selected tensor structures, constructed along continuations of resummed perturbation theory into the infrared and supplemented with information from the Slavnov-Taylor identities [189,222,[242][243][244][245][246][247]; (ii) explicit solutions of approximated Slavnov-Taylor identities [207]; and (iii) numerical solutions of truncations of the quark-gluon vertex DSE and FRGE [209,213,215,[248][249][250][251][252][253][254][255][256]. At least on a quantitative level the results from these approaches are not in very good agreement with each other.…”

Inhomogeneous chiral condensates

“…[189,16]). More recently DSEs have also been employed to study the QCD phase diagram at zero [190,191] and nonzero [192,193] chemical potential, including color superconductivity [194,195,196].…”

“…33 Besides the dressed quark propagator, which makes the simultaneous solution of Eqs. (193) and (194) a selfconsistency problem, the selfenergy depends on the dressed gluon propagator D µν and the bare and dressed quark-gluon vertices, gΓ a,0 µ and gΓ a ν , respectively, where g is the QCD coupling constant. At this point Müller et al truncated the system by using a semi-phenomenological model input, instead of calculating D µν and Γ a ν from higher-order DSEs.…”