110 citations · 485 across the 58 of their papers we have counts for
30 papers · 1 filter
Comment on "Two-photon decay of the sigma meson"
Eef van Beveren, Frieder Kleefeld, George Rupp +1
We comment on a recent paper by Giacosa, Gutsche, and Lyobovitskij, in which it is argued that a quarkonium interpretation of the meson should give rise to a much smaller two-p…
Radiative decays with a0(980) and f0(980) from ChPT at order p^4
S. Ivashyn, A. Korchin
A consistent description of the pi0 pi0 invariant mass distribution in the phi(1020) -> f0(980) gamma -> pi0 pi0 gamma decay and the pi0 eta in phi(1020) -> a0(980) gamma -> pi0 et…
On the Dynamical Generation of Quark-Level-Linear-Sigma-Model-like Theories beyond one Loop
F. Kleefeld
A self-consistent strategy to complete the dynamical generation of Quark-Level-Linear-Sigma-Model-like Lagrangean theories beyond one loop as proposed in more detail in our manuscr…
$D^+ \to K^- \p^+ \p^+ $: the low-energy sector
D. R. Boito, P. C. Magalhães, M. R. Robilotta +1
An effective chiral lagrangian, which includes scalar resonances, is used to describe the process $D^+ \rar K^- \p^+ \p^+$ at low-energies. Our main result is a…
New formula for a resonant scattering near an inelastic threshold
L. Lesniak
We show that the Flatte formula is not adequate to interpret precision data on a resonance production near an inelastic threshold. A unitary parameterization, satisfying generalize…
Review of Scalar Mesons
D. V. Bugg
The formulae needed to parametrise sigma, kappa, a0(980) and f0(980) are reviewed. For sigma and kappa, the Adler zero due to Chiral Symmetry Breaking plays a crucial role. The f0(…
The Light Scalar Mesons a_0/f_0(980) at COSY-Juelich
M. Buescher
The light scalar mesons a_0/f_0(980) are being investigated at COSY-Juelich by detecting the strong decays into K-K-bar and pi-eta/pi-pi as well as radiative decays into vector mes…
On how to complete the Dynamical Generation of Quark-Level Linear Sigma Model like Theories beyond one Loop
F. Kleefeld
A self-consistent strategy is proposed to complete in a renormalization scheme independent way the dynamical generation of Quark-Level Linear Sigma Model like Lagrangean theories b…
Constituent and current quark masses at low chiral energies
M. D. Scadron, F. Kleefeld, G. Rupp
Light constituent quark masses and the corresponding dynamical quark masses are determined by data, the Quark-Level Linear Model, and infrared QCD. This allows to define effect…
Comment on "Mass and Width of the Lowest Resonance in QCD"
F. Kleefeld
I. Caprini's, G. Colangelo's, and H. Leutwyler's (CCL) article "Mass and Width of the Lowest Resonance in QCD", Phys. Rev. Lett. 96, 132001 (2006) [hep-ph/0512364], is critically r…
On the absence and presence of pole(s) in fermion propagator in the simple model with mass generation
V. Sauli, F. Kleefeld
Within the Pauli-Villars regularization technique the fermion propagator is studied in the framework of Schwinger-Dyson equations in the Euclidean space. Making the generalization…
Pion and Kaon Masses and Pion Form Factors from Dynamical Chiral-Symmetry Breaking with Light Constituent Quarks
Michael D. Scadron, Frieder Kleefeld, George Rupp
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 effe…
Small Strange Quark Content of Protons
Michael D. Scadron, Frieder Kleefeld, George Rupp
The contribution of strange sea quarks to the proton mass and spin, as well as the related pion-nucleon sigma term, are briefly revisited, in the light of new experimental and latt…
The nature of , , and
E. van Beveren, D. V. Bugg, F. Kleefeld +1
Masses and widths of the four light scalar mesons , , (980) and (980) may be reproduced in a model where mesons scatter via a loop. A transition potentia…
Pion Chiral Symmetry Breaking in the Quark-Level Linear Sigma Model and Chiral Perturbation Theory
Michael D. Scadron, Frieder Kleefeld, George Rupp
Chiral symmetry breaking (ChSB) is reviewed to some extent within the quark-level-linear-sigma-model (QLLM) theory and standard chiral perturbation theory (ChPT). It is shown, o…
On a new unitarization scheme inspired by Dalitz and Tuan applied to meson-meson and meson-baryon scattering
F. Kleefeld
A new crossing symmetric unitarization scheme conveniently applied to meson-meson and meson-baryon scattering amplitudes is shortly proposed which can be not only used by theoretic…
On Scalar Meson Dominance in Semi- and Non-Leptonic Weak Pseudoscalar Meson Decays
F. Kleefeld
Aspects of Scalar Meson Dominance in semi- and non-leptonic weak pseudoscalar meson decays are shortly discussed on the basis of the Quark-Level Linear Sigma Model.
Complex Meson Spectroscopy
Eef van Beveren, Frieder Kleefeld, George Rupp
We do meson spectroscopy by studying the behavior of S-matrix poles in the complex-energy plane, as a function of the coupling strength for triplet-P-zero quark-pair creation. Ther…
From the Kappa via the Ds0*(2317) to the chi_c0: connecting light and heavy scalar mesons
Eef van Beveren, Joao E. G. N. Costa, Frieder Kleefeld +1
Pole trajectories connecting light and heavy scalar mesons, both broad resonances and quasi-bound states, are computed employing a simple coupled-channel model. Instead of varying…
Scalar mesons and Adler zeros
George Rupp, Frieder Kleefeld, Eef van Beveren
A simple unitarized quark-meson model, recently applied with success to light and charmed scalar mesons, is shown to encompass Adler-type zeros in the amplitude, due to the use of…
The Light and Heavy Scalars in Unitarized Coupled Channel and Lagrangian Approaches
F. Kleefeld
Using ideas underlying the flavour-blind "Nijmegen Unitarised Meson Model" we try to understand on the basis of a system of Schroedinger equations with one meson-meson and one (spi…
Ground-State Scalar Nonet: SU(3) Mass Splittings and Strong, Electromagnetic, and Weak Decay Rates
Michael D. Scadron, George Rupp, Frieder Kleefeld +1
By comparing SU(3)-breaking scales of linear mass formulae, it is shown that the lowest vector and scalar mesons all have a configuration, while the ground-state octet a…
SU(3) Mass Splittings for Mesons and Baryons
M. D. Scadron, G. Rupp, E. van Beveren +1
By comparing SU(3)-breaking scales of linear mass formulae, it is shown that the lowest vector, axial-vector, and scalar mesons all have a configuration, while the groun…
The light scalar mesons within quark models
Eef van Beveren, George Rupp, Nicholas Petropoulos +1
Low-energy meson-meson scattering data are a powerful testing ground for quark models. Here, we describe the behaviour at threshold of S-wave scattering-matrix singularities. The m…