Related papers: Multiple pion production from an oriented chiral c…
Recent attempts to determine the pion polarizability by dispersion relations yield values that disagree with the predictions of chiral perturbation theory. These dispersion relations are based on specific forms for the absorptive part of…
We present results for the large-$N$ limit of the chiral condensate computed from twisted reduced models. We followed a two-fold strategy, one constiting in extracting the condensate from the quark-mass dependence of the pion mass, the…
We consider the quantum state describing theDisoriented Chiral Condensate (DCC), which may be produced in high energy collisions. We show how a mean field treatment of the quantum equations corresponding to the classical linear sigma model…
Enhancement of omega and antiomega baryon production in Pb+Pb collisions at a c.m. energy of 17 A GeV can be explained by the formation of many small disoriented chiral condensate regions. This explanation implies that neutral and charged…
We analyze various aspects of pion and kaon condensation in the framework of chiral perturbation theory. Considering a system at vanishing temperature and varying the isospin chemical potential and the strange quark chemical potential we…
The probability distribution of a neutral pion fraction from independent domains of disoriented chiral condensate is characterized. The signal for the condensate is still clear for a large number of independent domains if one of them is…
We show that the combined effects of a rotation plus a magnetic field can cause charged pion condensation. We suggest that this phenomenon may yield to observable effects in current heavy ion collisions at collider energies, where large…
In this work we study the thermodynamic properties of the pion gas starting from the realistic elastic scattering phase-shifts obtained from Chiral Perturbation Theory and using the virial expansion. In particular we study the state…
The posibility of large charge and isospin fluctuations in high-energy heavy ion-collisions is studied within the framework of the nonlinear $\sigma $-model with quark degrees of freedom. The multipion exchange potential between two quarks…
We present two-loop results for the quark condensate in an external magnetic field within chiral perturbation theory using coordinate space techniques. At finite temperature, we explore the impact of the magnetic field on the pion-pion…
We address the issue of whether a region of disordered chiral condensate (DCC), in which the chiral condensate has components along the pion directions, can form. We consider a system going through the chiral phase transition either via a…
The physics of pions within a finite volume is explored using lattice regularized chiral perturbation theory. This regularization scheme permits a straightforward computational approach to be used in place of analytical continuum…
Chiral perturbation theory is the effective field theory of the strong interactions at low energies. We will give a short introduction to chiral perturbation theory for mesons and will discuss, as an example, the electromagnetic…
Isospin density and thermal corrections for several condensates are discussed, at the one-loop level, in the frame of chiral dynamics with pionic degrees of freedom. The evolution of such objects give an additional insight into the…
Disoriented chiral condensates or long wavelength pionic oscillations and their interaction with the thermal environment can be a significant source of dileptons. We calculate the yield of such dilepton production within the linear sigma…
The invariant amplitudes for pion electroproduction on the nucleon are evaluated by dispersion relations at constant t with MAID as input for the imaginary parts of these amplitudes. In the threshold region these amplitudes are confronted…
The pseudoscalar projection of the pion's Poincare'-covariant Bethe-Salpeter amplitude onto the light-front may be understood to provide the probability distribution of the chiral condensate within the pion. Unlike the parton distribution…
We analyse the extension of Chiral Perturbation Theory to describe a meson gas out of thermal equilibrium. For that purpose, we let the pion decay constant be a time-dependent function and work within the Schwinger-Keldysh contour…
Disoriented chiral condensate can produce novel fluctuations of kaons as well as pions. Robust statistical observables can be used to extract the novel fluctuations from background contributions in K-short and K-charged correlation…
Numerical simulations of the chiral phase transition in the (3+1)dimensional O(4)-model are presented. The evolutions of the chiral field follow purely dissipative dynamics, starting from random chirally symmetric initial configurations…