Related papers: Confinement and the Pion Nucleon Sigma Term
We apply the perturbative chiral quark model (PCQM) at one loop to analyse meson-baryon sigma-terms. Analytic expressions for these quantities are obtained in terms of fundamental parameters of low-energy pion-nucleon physics (weak pion…
Several new theoretical and experimental developments concerning the determination of the nucleon sigma term are presented and discussed. Contribution to the Eighth International Symposium on Meson-Nucleon Physics and the Structure of the…
In the phenomenological description of the nuclear interaction a crucial role is traditionally played by the exchange of a scalar I=0 meson, the sigma, of mass 500-600 MeV, which however is not seen clearly in the particle spectrum and…
Earlier work suggested that the in-medium $\pi N$ threshold isovector amplitude $b_1(\rho)$ gets renormalized in pionic atoms by about 30% away from its $\rho=0$ free-space value, relating such renormalization to the leading low-density…
A status report is given for a joint project of the Budapest-Marseille-Wuppertal collaboration and the Regensburg group to study the quark mass-dependence of octet baryons in SU(3) Baryon XPT. This formulation is expected to extend to…
We introduced here the study of a QCD based on a complex group. Our aim is to show that a gauge theory with a complex symmetry develops some of the features required for the description of a confined phase. This theory leads to gluons with…
A new result for the nucleon sigma term from an updated pion-nucleon partial-wave and dispersion relation analysis of the Virginia Polytechnic Institute (now George Washington University) group is discussed. Using a method similar to that…
Planar Chern-Simons (CS) theories in which a compact abelian gauge group U(1) x U(1) is spontaneously broken to U(1) x Z_N are investigated. Among other things, it is noted that the theories just featuring the mixed CS term coupling the…
I give a brief description of Gribov's light quark confinement scenario and of the Gribov--Dyson--Schwinger equation for light quarks. It is shown that the Green function obtained from this equation exhibits chiral symmetry breaking.
The concept of a (de)confined phase in QFT is well-defined in the presence of $1$-form symmetries and their spontaneous symmetry breaking. However, in scenarios where such symmetries are absent, confinement is not a well-defined phase…
This paper describes a phenomenon in which all but a tiny fraction of the fundamental holographic degrees of the SYK theory are confined (as in quark confinement) in the double-scaled infinite temperature limit. The mechanism for…
The pion nucleon sigma-term is extracted on the basis of the soliton picture of the nucleon from the mass spectrum of usual and the recently observed exotic baryons, assuming that they have positive parity. The value found is consistent…
The confinement scenario in N=2 supersymmetric gauge theory at the monopole point is reviewed. Basic features of this U(1) confinement are contrasted with those we expect in QCD. In particular, extra states in the hadron spectrum and…
We study quark confinement by computing the Polyakov loop potential in Yang--Mills theory within different non-perturbative functional continuum approaches [1]. We extend previous studies in the formalism of the functional renormalisation…
The in-medium chiral condensate is studied with a new approach which has the advantage of no need for extra assumptions on the current mass derivatives of model parameters. It is shown that the pion-nucleon sigma term is 9/2 times the…
We consider a Coulomb potential plus a confinement potential $ A r^{\nu} $ and we study which of the two terms is dominant in the description of quarkonia. We find that in general the term of confinement is dominant, which allows us to…
We present a lattice-QCD based analysis of the nucleon sigma terms using gauge ensembles with $N_f = 2 + 1$ flavors of ${\cal O}(a)$-improved Wilson fermions, with a complete error budget concerning excited-state contaminations, the chiral…
In this paper we present a new model for a gauge field theory such that self-interacting spin-one particles can be confined in a compact domain. The necessary conditions to produce the confinement appear already in the properties of the…
The pion-nucleon sigma term, characterizing the mass component of Higgs origin related to $u$ and $d$ quarks inside the nucleon, is investigated within relativistic baryon chiral perturbation theory at leading two-loop order using the…
We study the pion-nucleon sigma term in vacuum and in nuclear matter in the framework of global color model of QCD. With the effective gluon propagator being taken as the $\delta$-function in momentum space of Munczek-Nomirovsky model, we…