Related papers: Impact Representation of Generalized Distribution …
Using the spectral representation of the quark propagator we study the Dirac decomposition of the gauge invariant quark propagator, whose imaginary part describes the hadronization of a quark as this interacts with the vacuum. We then…
Heavy-flavor hadrons produced in ultra-relativistic heavy-ion collisions are a sensitive probe for studying hadronization mechanisms of the quark-gluon-plasma. In this work, we survey how different transport models for the simulation of…
The gamma p ---> pi+ pi- p reaction, in combination with data from the pi N ---> pi pi N reaction, allows one to obtain the s- and d-wave amplitudes for the N*(1520) decay into Delta pi with absolute sign with respect to the N*(1520) ---> N…
We have shown that the lowest order QCD amplitude, i.e. the quark exchange contribution, to the forward production of a pair of longitudinally polarized rmesons in the scattering of two virtual photons gamma (Q1) gamma (Q2) rho rho…
Within the framework of light-cone quantization we derive the overlap representation of generalized parton distributions for transversely polarized quarks using the Fock-state decomposition in the transverse-spin basis. We apply this…
The interplay of pQCD, pion exchange and FSI effects is studied for the gamma gamma --> pi^+ pi^- reaction in the region of 2 GeV < W_{gamma gamma} < 6 GeV. We find strong interference effects between pQCD and soft pion-exchange amplitudes…
The transversity generalized parton distributions (tGPDs) of the the pion, involving matrix elements of the tensor bilocal quark current, are analyzed in chiral quark models. We apply the nonlocal chiral models involving a…
We propose to describe the process $ p ~ \bar{p} \rightarrow \pi^+ ~ \pi^-$ in a perturbative, QCD motivated framework in which a hard $ud \, \bar{u} \bar{d} \rightarrow d \, \bar{d} $ annihilation factorizes from soft transition…
We present the generalized parton distributions (GPDs) for the valence quarks of the pion and the kaon in both momentum space and position space within the basis light-front quantization framework. These GPDs are obtained from the…
The electromagnetic decays of the ground state baryon multiplets with one heavy quark are calculated using Heavy Hadron Chiral Perturbation Theory. The M1 and E2 amplitudes for S^{*}--> S gamma, S^{*} --> T gamma and S --> T gamma are…
We consider several classes of analytic parametrizations of hadronic scattering amplitudes, and compare their predictions to all available forward data in hadron-hadron, gamma-p and gamma-gamma reactions. Although these parametrizations are…
Helicity-dependent generalized parton distributions of the nucleon are derived from the overlap representation of generalized parton distributions using light-cone wave functions obtained in constituent quark models. Results from two…
While the chiral-even content of the nucleon is better and better studied, the chiral-odd transversity generalized parton distributions (GPDs) remain almost unknown. These GPDs can be accessed experimentally through the exclusive…
$\gamma^* \gamma \to B \bar{B}$ is the golden process to access chiral-even di-baryon generalized distribution amplitudes (GDAs) as deeply virtual Compton scattering has proven to be for the generalized parton distributions. In the…
In this HADRON2001 contribution we summarize the status of our quark-model calculations of hadron-hadron scattering amplitudes in annihilation-free channels. The predictions are in reasonably good agreement with experimentally known S-wave…
We develop a new formulation of the quark coalescence model by including the quark number conservation in order to describe the hadronization of the bulk of the quark-gluon plasma. The scalings between hadron and quark phase space…
In this paper we perform an amplitude analysis of essentially all published pion and kaon pair production data from two photon collisions below 1.5 GeV. This includes all the high statistics results from Belle, as well as older data from…
A model for dihadron fragmentation functions is briefly outlined, that describes the fragmentation of a quark in two unpolarized hadrons. The parameters are tuned to the output of the PYTHIA event generator for two-hadron semi-inclusive…
We evaluate the amplitude for gamma gamma --> pi^+ pi^- to two loops in the framework of chiral perturbation theory.The three new coupling constants that enter the result at this order in the low-energy expansion are estimated via resonance…
An approach is proposed to calculate Generalized Parton Distributions (GPDs) in a Constituent Quark Model (CQM) scenario. These off-diagonal distributions are obtained from momentum space wave functions to be evaluated in a given non…