Related papers: On the sigma sigma term
We study the light quark mass dependence of the f_0(600), kappa(800), rho(770) and K*(892) resonance parameters generated from elastic meson-meson scattering using unitarized one-loop Chiral Perturbation Theory. First, we show that it is…
The radiative decays of heavy mesons and heavy baryons are studied in a formalism which incorporates both the heavy quark symmetry and the chiral symmetry. The chiral Lagrangians for the electromagnetic interactions of heavy hadrons consist…
A new dispersion relation for the partial wave $\pi\pi$ scattering $S$ matrix is set up. Using the dispersion relation we generalize the single channel unitarity condition, $SS^+=1$, to the entire complex $s$ plane, which is equivalent to…
The pole mass of a heavy quark is ambiguous by an amount of order $\Lambda_{QCD}$. We show that the heavy-quark potential, $V(r)$, is similarly ambiguous, but that the total static energy, $2M_{pole}+V(r)$, is unambiguous when expressed in…
The dimensionless parameter $\xi = M_\pi^2/(16 \pi^2 F_\pi^2)$, where $F_\pi$ is the pion decay constant and $M_\pi$ is the pion mass, is expected to control the convergence of chiral perturbation theory applicable to QCD. Here we…
We review our recent study of the pion mass dependence of the rho and sigma resonances generated from one-loop SU(2) Chiral Perturbation Theory (ChPT) with the Inverse Amplitude Method (IAM) which was modified to properly account for the…
Lattice QCD spectra can be used to constrain partial-wave scattering amplitudes that, while satisfying unitarity, do not have to respect crossing symmetry and analyticity. This becomes a particular problem when extrapolated far from real…
The relevance of the pion mass, provenient from a term which explicitely breaks chiral symmetry in the Lagrangian, for nucleon magnetic moment in the frame of the Skyrmion model in two different versions: the usual Skyrme model and a…
Light constituent quark masses and the corresponding dynamical quark masses are determined by data, the Quark-Level Linear $\sigma$ Model, and infrared QCD. This allows to define effective nonstrange and strange current quark masses which…
For large values of the Higgs mass the low energy structure of the gauged linear sigma model in the spontaneously broken phase can adequately be described by an effective field theory. We present a manifestly gauge-invariant functional…
This report summarizes the most important results presented at the recent conference held at the Yukawa Institute of Theoretical Physics in Kyoto, devoted to the recently confirmed light sigma resonance. Remarkably, all speakers at this…
We construct pi-pi amplitudes that fulfill exact elastic unitarity, account for one loop Chiral Perturbation Theory contributions and include all 1/Nc leading terms, with the only limitation of considering just the lowest-lying nonet of…
We review the quark-mass dependence of the baryon octet and decuplet masses as obtained from recent lattice simulations of the BMW, PACS-CS, LHPC, HSC and QCDSF-UKQCD groups. Our discussion relies on the relativistic chiral Lagrangian and…
By looking at the complex plane of the pion-mass squared we establish a dispersion relation which the static quantities, such as baryon masses, magnetic moments, polarizabilities, should obey. This dispersion relation yields insight into…
We study the resonance energy of the strange dibaryons using two models with the energy-independent and energy-dependent potentials for the s-wave barKN interaction, both of which are derived by certain reductions from the leading order…
We study nuclear matter and finite nuclei with a chiral Lagrangian which generalizes the linear $\sigma$ model and also accounts for the QCD trace anomaly by means of terms which involve the $\sigma$ and $\vmg{\pi}$ fields as well as the…
Within the scenario of chiral freedom we compute the quark and lepton masses of the first two generations in terms of their chiral couplings. This allows us to make a rough estimate of the size of the chiral couplings, narrowing down the…
After a brief summary of the QCD phase structure with light quarks, we discuss two recent developments on in-medium hadrons. First topic is the sigma-meson which is a fluctuation of the chiral order parameter \bar{q}q. Although sigma is at…
Resonance pole positions of the $f_0(500)$ alias $\sigma(500)$ meson are computed and plotted as a continuous function of pion mass in the framework of a unitary and analytic coupled-channel model for scalar mesons as dynamical $q\bar{q}$…
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…