Related papers: Vector mesons and electromagnetic form factor of t…
We present a preliminary study toward a lattice determination of the vector and scalar form factors of the $B \to \pi \ell \nu$ semileptonic decays. We compute the form factors relative to the transition between heavy-light pseudoscalar…
We systematically investigate the electromagnetic form factors of heavy-light pseudo-scalar and vector mesons within the Dyson-Schwinger/Bethe-Salpeter equations framework for the first time. It is found that the charge radius of vector…
We study hyperon resonances by solving coupled channel scattering equations. The coupled systems include pseudoscalar- and vector-baryon channels. The parameters of the model are restricted by making a $\chi^2$-fit to the cross section data…
We present the first lattice QCD determination of the $\Lambda \to N$ vector and axial-vector form factors, which are essential inputs for studying the semileptonic decay $\Lambda \to p \ell \bar{\nu}_\ell$. This channel provides a clean,…
During the last year, analytic expressions for the two-loop QCD corrections to the form factors for the vector, axial-vector, scalar and pseudo-scalar vertices involving a pair of heavy quarks, $Q \bar{Q}$, were calculated. The results are…
We report a set of measurements of inclusive invariant transverse momentum differential cross sections of lambda, cascade and omega hyperons reconstructed in the central region with pseudorapidity within 1 and transverse momentum up to 10…
We present a determination of the scalar and tensor $\Lambda\to p$ transition form factors using lattice QCD. These form factors are relevant for semileptonic hyperon decays in the presence of extensions of the Standard Model that include…
We extend our previous formulation of low-energy QCD in terms of an effective lagrangian containing operators of dimensionality $d\le 6$ constructed with pseudoscalars and quark fields, describing physics below the scale of chiral symmetry…
There has been considerable progress in the study of the electromagnetic form factors of baryons in the timelike region, through electron-positron scattering reactions ($e^+ e^- \to B \bar B$), in the last two decades. Timelike experiments…
The possibility of measuring the proton electromagnetic form factors in the time-like region at FAIR with the \PANDA detector is discussed. Detailed simulations on signal efficiency for the annihilation of $\bar p +p $ into a lepton pair as…
The electromagnetic (EM) form fators of the pseudoscalar and vector mesons are calculated in the light-front framework. We extract these form factors from the relevant matrix elements directly, instead of choosing the Breit frame. The…
We analyze the reactions gamma+p => M+B, with M B being either K+ Lambda, K+ Sigma0, or pi+ n, within perturbative QCD, allowing for diquarks as quasi-elementary constituents of baryons. The diquark-model parameters and the quark-diquark…
The reaction $e^+e^- \to \bar \Lambda \Lambda$ is investigated for energies close to the threshold. Specific emphasis is put on the role played by the interaction in the final $\bar \Lambda \Lambda$ system which is taken into account…
Using a quite accurate flavour-independence of $nS$-level mass differences in heavy quarkonia and a corresponding quasiclassical expression for the heavy quark binding energy, one shows that experimental data on masses of mesons with heavy…
The current situation for vector meson spectroscopy is outlined, and it is shown that the data are inconsistent with the generally-accepted model for meson decay. A possible resolution in terms of exotic (hybrid) mesons is given. Although…
In Ultra Relativistic Heavy-Ion Collisions (URHIC's) the light vector mesons play a crucial role in the description of hadronic interactions in a non-pertrubative QCD region. In this region efective hadron models use composite hadrons and…
The cross sections for several $\gamma \gamma \to VV$ processes exhibit strong enhancements near threshold, where $V$ denotes a vector meson. The pattern of these enhancements is not well understood; for example, $\gamma \gamma \to \rho^0…
A model is developed for electromagnetic form factor of the pion. One-loop corrections are included in the linear sigma-model. The rho-meson contribution is added in an extended VMD model. The form factor, calculated without fitting…
Masses of pseudoscalar and vector mesons, which are ground states of light or/and heavy quarks and antiquarks, have been calculated in the framework of an extended model of quasi-independent quarks with absolute uncertainties about 30 MeV.…
The total cross sections of the process $e^+ e^-\to \Lambda_c^+ \bar{\Lambda}_c^-$ close to the threshold are calculated within the vector meson dominance model. It is found that the theoretical results can describe the current experimental…