Related papers: The S parameter in a technicolour model with expli…
We derive the the effective lagrangian that describes the interactions among vector, axial-vector mesons and pseudoscalars starting from the extended chiral quark model (ECQM). The results for the low-energy constants of this effective…
The possible different phases of cold quark matter in the presence of a finite magnetic field and chemical potential are obtained within the SU(3) NJL model for two parameter sets often used in the literature. Although the general pattern…
We show how to incorporate chiral symmetry breaking in the soft-wall version of the AdS/QCD model by using a modified dilaton profile and a quartic term in the bulk scalar potential. This allows one to separate the dependence on spontaneous…
We study the S parameter, considering especially its sign, in models of electroweak symmetry breaking (EWSB) in extra dimensions, with fermions localized near the UV brane. Such models are conjectured to be dual to 4D strong dynamics…
Corrections motivated by chiral symmetry arguments have long been known to give important contributions to hadronic observables, particularly at low momentum transfer. It is possible to separate these approaches into two broad groups;…
We investigate the dynamical chiral symmetry breaking and its restoration at finite density and temperature within the two-flavor Nambu-Jona-Lasinio model, and mainly focus on the critical behaviors near the critical end point (CEP) and…
I compare the tree level estimate of the electro-weak precision parameters in two (exactly solvable) toy models of dynamical symmetry breaking in which the strong dynamics is assumed to be described by a five-dimensional (weakly coupled)…
Radiative corrections to electroweak parameters in technicolor theories may be evaluated by one of two techniques: either one estimates spectral function integrals using scaled QCD data, or one uses naive dimensional analysis with a chiral…
In pursuit of the sketching the effective magnetized QCD phase diagram, we found conditions on the critical coupling for chiral symmetry breaking in the Nambu-Jona-Lasinio model in a nontrivial thermo-magnetic environment. Critical values…
We investigate the isospin symmetry breaking effects within a recently derived Nambu-Jona-Lasinio related model by fitting the measured pseudoscalar meson masses and weak decay couplings $f_\pi$, $f_K$. Our model contains the next to…
We study the solutions of the gap equation, the thermodynamic potential and the chiral susceptibility in and beyond the chiral limit at finite chemical potential in the Nambu--Jona-Lasinio (NJL) model. We give an explicit relation between…
We consider chiral symmetry breaking AdS / QCD models with cubic and quartic potentials in the scalar sector and a z dependent mass for scalars in the bulk. In these models it is possible to get good mesonic spectra using current quark…
We study the $CP$-violating, $|\Delta S| =1$ parameter $\varepsilon '/\varepsilon$ by computing the hadronic matrix elements in the chiral quark model. We estimate the coefficients of the next-to-leading order terms in the chiral expansion…
This is a brief summary of topics that were presented as lectures within the programme "New Frontiers in QCD 2010" at the Yukawa Institute of Theoretical Physics in Kyoto. The basic subject is phases and symmetry breaking patterns as they…
Dynamical chiral-symmetry breaking in QCD is studied with the Schwinger-Dyson (SD) formalism based on lattice QCD data, i.e., LQCD-based SD formalism. We extract the SD kernel function $K(p^2)$ in an Ansatz-independent manner from the…
We study the dynamical chiral symmetry breaking/restoration for the various numbers of light quarks flavors $N_f$ and colors $N_c$, using the Nambu-Jona-Lasinio (NJL) model of quarks, dressed with a color-flavor dependence of effective…
Based on the AdS/CFT correspondence we study the breaking of the chiral symmetry in QCD using a simple five dimensional model. The model gives definite predictions for the spectrum of vector mesons, their decay constants and interactions as…
Recently the Lattice Strong Dynamics Collaboration reported a reduction of the electroweak S parameter for SU(3) gauge theory with Nf=6 fermions in the fundamental representation, compared to scaled-up QCD (arXiv:1009.5967). Here I provide…
We present a derivation of the low-energy effective meson Lagrangian of the Nambu -- Jona-Lasinio (NJL) model on the basis of Schwinger's proper-time regularization of the one-loop fermion determinant. We consider the case in which the…
Chiral theories with spontaneous symmetry breaking such as the Nambu-Jona-Lasinio (NJL) model lead to the existence of a scalar mode. We present in a detailed manner how the corresponding low momentum effective lagrangian involving the…