Related papers: Composite vertices that lead to soft form factors
Recently, Stech found form factor relations for heavy to light transitions based on two simple dynamical assumptions for spectator partical. In this work we generalize his approach to the case of baryons and find that for…
This article reviews the current status of experimental results obtained in the measurement of light vector mesons produced in proton-proton and heavy ion collisions at different energies. The review is focused on two phenomena related to…
In this article, we analyze the electromagnetic form factors of the vector heavy-light mesons to the pseudoscalar heavy-light mesons in the framework of three-point QCD sum rules, where the contributions of vacuum condensate terms…
We study the role of semi-classical QCD vacuum solutions in high energy scattering by considering the instanton contribution to hadronic cross sections. We propose a new type of instanton-induced interactions (``instanton ladder'') that…
Soft QCD is beyond perturbative control, and therefore phenomenological models have to be developed. These are implemented and combined within event generators. Typical aspects considered are multiparton interactions, colour reconnection,…
We review the approach to modeling soft hadron physics observables based on the Dyson-Schwinger equations of QCD. The focus is on light quark mesons and in particular the pseudoscalar and vector ground states, their decays and…
In gauge theories with slowly-running coupling constants, it may be possible for four-fermion operators to be nearly marginal. Such operators can possess asymptotically weak couplings, and can plausibly give rise to light composite vector…
The main assumption of the model is that in soft processes mesons behave like systems made of valence quarks and an effective vacuum- like field. The 4-momentum of the latter represents the relativistic generalization of the potential…
Relations between the form factors that parametrize the hadronic matrix elements, in spectator decays of heavy mesons, have been derived by Stech within the constituent quark model. In here, we examine these relations using a slightly…
Measurements and theoretical calculations of meson form factors are essential for our understanding of internal hadron structure and QCD, the dynamics that bind the quarks in hadrons. The pion electromagnetic form factor has been measured…
In this paper we consider the soft processes at LHC energies in the framework of the Constituent Quark Model (CQM). We show that this rather naive model is able to describe all available soft data at lower energies and to predict the…
QCD sum rules for the determination of form factors of $\Lambda_b$ and $\Lambda_c$ semileptonic decays are investigated. With a form for the baryonic current appropriate for the limits of the heavy quark symmetries, the different tensor…
The quark-level linear sigma model is employed to compute a variety of electromagnetic and weak observables of light mesons, including pion and kaon form factors and charge radii, charged-pion polarizabilities, semileptonic weak $K_{\ell3}$…
The electromagnetic form factors of light and heavy pseudoscalar mesons are calculated within two covariant constituent-quark models, a light-front and a dispersion relation approach. We investigate the details and physical origins of the…
We calculate the form factors for weak decays of $B_{(s)}$ and $D_{(s)}$ mesons to light pseudoscalar and vector mesons within a relativistic dispersion approach based on the constituent quark picture. This approach gives the form factors…
We apply a modified vector meson dominance (VMD) model to analyze the electromagnetic form factors of the $\Lambda_c$ hyperon in the time-like reaction $e^+e^-\rightarrow \Lambda_c^+ \bar{\Lambda}_c^-$. In the model, we include the…
In the framework of the soft-collinear effective theory, we demonstrate that the leading-power heavy-to-light baryonic form factors at large recoil obey the heavy quark and large energy symmetries. Symmetry breaking effects are suppressed…
Light front formalism for composite systems is presented. Derivation of equations for bound state and scattering problems are given. Methods of constructing of elastic form factors and scattering amplitudes of composite particles are…
Within the Standard Model, we investigate the weak decays of $\Lambda_b \to \Lambda + \gamma$ and $\Lambda_b \to \Lambda + l^{+} l^{-}$ with the light-cone sum rules approach. The higher twist distribution amplitudes of $\Lambda$ baryon to…
We present a `new generation' model for high energy proton-proton `soft' interactions. It allows for a full set of multi-Pomeron vertices, as well as including multichannel eikonal scattering. It describes the behaviour of the proton-proton…