Related papers: RChL currents in Tauola: implementation and fit pa…
tau -> (3 pions) nu_tau decays are analysed within the framework of the resonance effective theory of QCD. We work out the relevant Lagrangian that describes the axial-vector current hadronization contributing to these processes, in…
We calculate the processes e+ e- -> 4 pions and tau -> nu_tau + 4 pions to O(p^4) in the low-energy expansion of the standard model. The chiral amplitudes of O(p^4) can be extended via resonance exchange to energies around 1 GeV.…
Pion electro- and photoproduction off the nucleon close to threshold is studied in covariant baryon chiral perturbation theory at O($p^3$) in the extended-on-mass-shell scheme, with the explicit inclusion of the $\Delta(1232)$ resonance.…
An exposition is made of recent developments using techniques of unitary chiral perturbation theory, $U \chi P T$, which allows one to extend predictions using chiral Lagrangians to higher energies than ordinary chiral perturbation theory,…
An extended $U(3)_L\bigotimes U(3)_R$ chiral theory which includes pseudoscalar and vector meson nonets as dynamic degrees of freedom is presented. We combine a hidden symmetry approach with a general procedure of including the $\eta'$…
We study the two-pion exchange potential at next-to-next-to-leading order in chiral effective field theory. We propose a new cut-off scheme for the pion loop integrals based on spectral function regularization. We show that this method…
We present a relativistic procedure for the chiral expansion of the two-pion exchange component of the $NN$ potential, which emphasizes the role of intermediate $\pi N$ subamplitudes. The relationship between power counting in $\pi N$ and…
In this paper we study two kinds of tau decays: (a) tau- --> (rho pi-,omega pi-, phi pi-, K*0 K-) nu(tau), which belong to Delta S=0 processes and (b) Delta S = 1 processes, like tau- --> (rho K-, omega K-, phi K-, \bar{K*0} pi-) nu(tau),…
A simple chiral quark model of the Nambu--Jona-Lasinio (NJL) type with a quark confinement mechanism is constructed for the description of the light meson sector of QCD at finite temperature. Unphysical quark production thresholds in the…
It is shown that there exists a possibility of amplification of amplitudes of quantum pion modes with low momenta in the late time of chiral phase transition by using the Gaussian wave functional approximation in the O(4) linear sigma…
The ground state parameters of the two-dimensional S=1/2 antiferromagnetic Heisenberg model are calculated using the Stochastic Series Expansion quantum Monte Carlo method for L*L lattices with L up to 16. The finite-size results for the…
Multiple partonic interactions are widely used to simulate the hadronic final state in high energy hadronic collisions, and successfully describe many features of the data. It is important to make maximum use of the available physical…
We consider in details the dual models for the Goldstone mesons (pions) scattering in the presence of the explicit chiral symmetry breaking caused by non-zero current quark mass. New method of incorporation of the quark masses into the dual…
Using chiral perturbation theory and the large-$N_c$ expansion, we obtain expressions for the $\eta'$ mass and $\eta - \eta'$ mixing in terms of low-energy chiral Lagrangian parameters. This is accomplished through an intermediate step of…
Chiral phase properties of finite size hadronic systems are investigated within the Nambu--Jona-Lasinio model. Finite size effects are taken into account by making use of the multiple reflection expansion. We find that, for droplets with…
We study the mass, width and couplings of the lightest vector multiplet. Effective field theories based on chiral symmetry and a 1/N_C counting are adopted in order to describe the vector form factor associated to the two-pseudoscalar…
We study the two dimensional Hubbard model by use of the ground state algorithm in the Monte Carlo simulation. We employ complex wave functions as trial function in order to have a close look at properties such as chiral spin order…
Muon pair production through the radiative return is of importance for a measurement of the hadronic production cross section in two ways: it provides an independent calibration and it may give rise to an important background for a…
The Monte Carlo event generators (MC) are used for the simulation of different processes in high energy physics. To achieve the best description of the data, the parameters of simulations are adjusted (tuned) with different methods. In this…
We present a brief account of the developments in the description of light meson resonances using unitarized extensions of the Chiral Perturbation Theory series, both in energy and temperature. In particular, we describe how these methods…