Related papers: Naive parton picture for kaon color transparency i…
We calculate quasi-exclusive scattering of a virtual photon and a proton or pion in nuclear targets. This is the first complete calculation of ``color transparency" and "nuclear filtering " in perturbative QCD. The calculation includes full…
The problem of nuclear propagation through the nuclear medium in quasielastic A(e,e'p) reactions is discussed in the kinematic range 1<Q^2<7 (GeV/c)^2. The coefficient of nuclear transparency is calculated for each Q^2 in the framework of…
Color transparency is the vanishing of initial and final state interactions, predicted by QCD to occur in high momentum transfer quasielastic nuclear reactions. For specific reactions involving nucleons, the initial and final state…
We use a semi-classical approximation to investigate the effects of color transparency on pion electroproduction reactions. The resulting reduced nuclear interactions produce significant, but not dominating, differences with the results of…
Colour transparency is a cute and indispensable property of QCD as the gauge theory of strong interaction. CT tests of QCD consist of production of the perturbative small-sized hadronic state and measuring the strngth of its…
In this article we review our work on the production of hadrons in the nuclear environment. We work with a string-breaking model for the initial production of hadrons and with a quantum-kinetic transport model (GiBUU) to describe the final…
Color transparency (CT) is a fundamental phenomenon in QCD in which hadrons produced in high-energy exclusive processes traverse nuclear matter with minimal interactions. Nuclear transparency, which quantifies this attenuation suppression,…
So far no theoretical tool for the comprehensive description of exclusive electroproduction of vector mesons off nuclei at medium energies has been developed. We suggest a light-cone QCD formalism which is valid at any energy and…
Quantum filtering of the ejectile wave packet from hard $ep$ scattering on bound nucleons puts stringent constraints on the onset of color transparency in $(e,e'p)$ reactions in nuclei at moderate energies. Based on multiple-scattering…
We have measured the nuclear transparency of the fundamental process $\gamma$ n $\to \pi^-$ p in $^4$He. These measurements were performed at Jefferson Lab in the photon energy range of 1.6 to 4.5 GeV and at $\theta^{\pi}_{cm}= 70^\circ$…
We introduce a data analysis procedure for color transparency experiments which is considerably less model dependent than the transparency ratio method. The new method is based on fitting the shape of the A dependence of the nuclear cross…
We review the current status of the phenomenon of Color Transparency (CT), a fundamental consequence of the description of hadrons from Quantum Chromo Dynamics. CT refers to the vanishing of final (and/or initial) state interactions with…
We find that the final state interactions in the $d(e,e'np)$ amplitude depend strongly on the final momentum of the spectator nucleon. This means that color transparency effects can be studied at rather low four-momentum transfer $Q^2\geq$…
We study the transparency $\cal T$ of nuclei for nucleons knocked-out in high-energy semi-inclusive $(e,e'p)$ reactions, using an improved theoretical input, discussed by Nikolaev et al. We establish that neglect of $NN$-correlations…
We examine the nuclear transparency for the quasi-elastic ($e, e'p$) process at large momentum transfers in a relativistic quantum-mechanical model for the internal structure of the proton, using a relativistic harmonic oscillator model. A…
Interference between vector mesons electroproduced at different longitudinal coordinates leads within Glauber approximation to a $Q^2$-dependence of nuclear effects similar to what is expected to be an onset of color transparency (CT). We…
Recent results from the NA49 experiment on the energy dependence of charged kaon production in central Pb+Pb collisions are presented. First results from the new data at 80 AGeV beam energy are compared with those from lower and higher…
The transparency of carbon for (p,2p) quasi-elastic events was measured at beam energies ranging from 6 to 14.5 GeV at 90 degrees c.m. The four momentum transfer squared q*q ranged from 4.8 to 16.9 (GeV/c)**2. We present the observed energy…
Kaon photo- and electroproduction off the nucleon is investigated in the framework of an isobaric model up to energies of about 1 GeV above threshold for all six isospin channels. The hadronic coupling constants in the model are determined…
Cross sections for the p($e,e'\pi^{+}$)n process on $^1$H, $^2$H, $^{12}$C, $^{27}$Al, $^{63}$Cu and $^{197}$Au targets were measured at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) in order to extract the nuclear…