9 research outputs found
Universal description of S-wave meson spectra in a renormalized light-cone QCD-inspired model
A light-cone QCD-inspired model, with the mass squared operator consisting of
a harmonic oscillator potential as confinement and a Dirac-delta interaction,
is used to study the S-wave meson spectra. The two parameters of the harmonic
potential and quark masses are fixed by masses of rho(770), rho(1450), J/psi,
psi(2S), K*(892) and B*. We apply a renormalization method to define the model,
in which the pseudo-scalar ground state mass fixes the renormalized strength of
the Dirac-delta interaction. The model presents an universal and satisfactory
description of both singlet and triplet states of S-wave mesons and the
corresponding radial excitations.Comment: RevTeX, 17 pages, 7 eps figures, to be published in Phys. Rev.
Electromagnetic form factor of the pion in the space- and time-like regions within the front-form dynamics
The pion electromagnetic form factor is calculated in the space- and
time-like regions from -10 up to 10 , within a
front-form model. The dressed photon vertex where a photon decays in a
quark-antiquark pair is depicted generalizing the vector meson dominance
ansatz, by means of the vector meson vertex functions. An important feature of
our model is the description of the on-mass-shell vertex functions in the
valence sector, for the pion and the vector mesons, through the front-form wave
functions obtained within a realistic quark model. The theoretical results show
an excellent agreement with the data in the space-like region, while in the
time-like region the description is quite encouraging.Comment: 9 pages + 4 figures. To appear in Phys. Lett.
S-wave Kpi scattering in chiral perturbation theory with resonances
We present a detailed analysis of S-wave Kpi scattering up to 2 GeV, making
use of the resonance chiral Lagrangian predictions together with a suitable
unitarisation method. Our approach incorporates known theoretical constraints
at low and high energies. The present experimental status, with partly
conflicting data from different experiments, is discussed. Our analysis allows
to resolve some experimental ambiguities, but better data are needed in order
to determine the cross-section in the higher-energy range. Our best fits are
used to determine the masses and widths of the relevant scalar resonances in
this energy region.Comment: 40 pages, 6 figure
Scalar Mesons in a Relativistic Quark Model with Instanton-Induced Forces
In a relativistic quark model with linear confinement and an
instanton-induced interaction which solves the - puzzle, scalar
mesons are found as almost pure SU(3) flavor states. This suggests a new
interpretation of the scalar nonet: We propose that the recently discovered
is not a glueball but the scalar (mainly)--octet meson for which
the decay mode is suppressed. The mainly--singlet state is
tentatively identified with the . The isovector and isodoublet states
correspond to the and , respectively.Comment: 10 pages including 2 uuencoded figures, RevTe