The role of strange quark mass in chiral QCD phase transition is examined, in the environment of relativistic nuclear collisions. The term in the effective potential of the O(4) universality class satisfies the stability requirement for a tricritical behaviour and can be used in order to study critical fluctuations in either side of the tricritical point . Comparing the corresponding patterns of density fluctuations in rapidity, one may distinguish the effects due to first- or second-order phase transition in A+A collisions.
Abstract We compute the critical behaviour of three-dimensional scalar theories using a new exact non-perturbative evolution equation. Our values for the critical exponents and other universal constants agree well with previous precision estimates. The evolution equation describes the scale dependence of the effective average action (coarse-grained effective action). It is not restricted to critical phenomena and can be used in the presence of massless (Goldstone) modes dealing successfully with...
Abstract We study, with various methods, the high-temperature phase transition for the N -component φ 4 theory in the large- N limit. Our results fully confirm a previous investigation of the problem, for arbitrary N , with the method of the average potential. The phase transition is of the second order with an effectively three-dimensional critical behaviour.
We study, with various methods (standard large N evaluation of the functional integral for the effective potential, solution of the Schwinger-Dyson equations), the high temperature phase transition for the Ncomponent \phi^4theory in the large Nlimit. Our results fully confirm a previous investigation of the problem, for arbitrary N with the method of the average potential which employs renormalization group ideas. The phase transition is of the second order with an effectively three-...
This paper reports that an earlier suggestion that the chiral phase transition in QCD for two flavors of massless quarks might be a second-order transition has gained credibility as a result of recent numerical simulations. One can test this hypothesis, and draw very specific quantitative consequences from it, using universality and renormalization group ideas. This hypothetical second order phase transition is in the universality class of a four component isotropic Heisenberg antiferromagnet---...
#2Robert B. Peschanski(CEA: French Alternative Energies and Atomic Energy Commission)H-Index: 21
Abstract We present predictions of random cascading models for multiparticle production at high energy. Standard and correlated factorial moments in rapidity are shown to provide stringent tests of the intermittency patterns characteristic of random cascades. Using the central limit theorem we show how to test directly for the existence of a cascading process. Finally, we discuss how to take into account statistical corrections.
Abstract It is proposed to study the dependence of factorial moments of the rapidity distribution on the size δy of the resolution. It is shown that if the fluctuations are purely statistical no variation of moments δy is expected, and thus observation of such a variation indicates the presence of genuine fluctuations of physical origin. The region in which the change occurs corresponds to the size (in rapidity) of the observed fluctuations. Intermittency, i.e. fluctuations of many different siz...
We investigate about the existence of static solitons solutions in the inverse G-L free energy in phase transitions of {\phi}4 theory. We calculate all the characteristics of these solitons , like localized structure, finite energy and mass . We show that solitons appears in spontaneous symmetry breaking (SSB) phenomenon only if the critical point is in excited state. When the time is introduced we shown that the static solitons of SSB remain as solitons in Minkowski space-time while the static ...
#1N. G. Antoniou(UoA: National and Kapodistrian University of Athens)H-Index: 18
#2Fotis K. Diakonos(UoA: National and Kapodistrian University of Athens)H-Index: 26
Last. M. Lahanas(UoA: National and Kapodistrian University of Athens)H-Index: 1
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Abstract The structure of events in relativistic heavy ion collisions (RHIC), associated with chiral QCD phase transition, is investigated. In particular the density fluctuations of pions, emitted from the excited vacuum (at T ≈ T c ), are studied and classified in terms of intermittency patterns in rapidity space. For this purpose a Monte Carlo simulation of critical events in the central region is presented, on the basis of the O (4) theory of chiral phase transition. The universal character o...