相关论文: Strangeness production via electromagnetic probes:…
the photoproduction of the lambda^0 and K^+ from circularly polarized photons on protons is discussed. Experiments and past theories are reviewed. We present a simple quark model, the results of which we compare to experiments
Previous approaches to the photo- and electro-production of strangeness off the proton, based upon effective hadronic Lagrangians, are extended here to incorporate the so called off-shell effects inherent to the fermions with spin >= 3/2. A…
Very recent eta and K+ photoproduction data on the proton from threshold up to E = 2.6 GeV are interpreted within a chiral constituent quark formalism, which embodies all known nucleon and hyperon resonances. Possible contributions from an…
After pioneering works on hypernuclei, strangeness production mechanisms have been studied in hadron collisions and photoreactions in the sixties. Recent experiments at SATURNE and COSY, in the hadronic sector, as well as ELSA and JLab, in…
We study strangeness (K^+, K^-, and Lambda) production and flow in Ni+Ni collisions at 1-2 AGeV, based on the relativistic transport model including the strangeness degrees of freedom. We find that strangeness spectra and flow are sensitive…
Differential cross-section and single polarization observables in the process gamma p --> K^+ Lambda are investigated within a constituent quark model and a dynamical coupled-channel formalism. The effects of two new nucleon resonances and…
Strangeness production has long been proposed as a diagnostic tool for understanding the dynamics of relativistic heavy ion collisions. In this presentation we review the traditional picture of strangeness enhancement as a signature for…
eta photoproduction data on the proton up to E=2 GeV are interpreted within a chiral constituent quark formalism, which embodies all known three and four star resonances. This study confirms the need for a new S11 resonance, with M=1.780…
An overview of the recent results on strangeness production and spectroscopy from the electron-proton collider experiments H1 and ZEUS at HERA is presented. Production of particles with light and strange quarks is discussed and compared…
We review the methods and results obtained in an analysis of the experimental heavy ion collision research program at nuclear beam energy of 160-200A GeV. We study strange, and more generally, hadronic particle production experimental data.…
The production of K+ and K- mesons below and at the NN threshold is summarized, based on a comparison of data with transport model calculations. K+ mesons are created in associate production together with hyperons (e.g. Lambda) in…
Photo- and electroproduction of $K\Sigma$ have been investigated near their production thresholds by using an effective Lagrangian approach. For this purpose, the background amplitude is constructed from suitable Feynman diagrams, whereas…
Data on mean numbers of $\Lambda$, $\bar\Lambda$, K's and on the total number $<s\bar s>$ of pairs of strange valence quarks in final state hadrons in hadronic and nuclear collisions at CERN- SPS energies are studied as a function of the…
Studies of the electromagnetic production of strange quarks began in the 1950s as something of a curiosity that puzzled experimentalists and theorists alike. As the datasets increased, concomitant advances in theoretical models were…
The chiral quark model describes the strangeness components of the light quarks as fluctuations into strange mesons and quarks. The single strange pseudoscalar and vector meson loop fluctuations of the constituent $u$- and $d$-quarks give…
We discuss strangeness production close to threshold in p+A and A+A collision. Comparing the body of available K+, K0, K-, and Lambda data with the IQMD transport code and for some key observables as well with the HSD transport code, we…
In view of the numerous experimental results recently released, we provide in this letter an update on the performance of our simple Regge model for strangeness electroproduction on the nucleon. Without refitting any parameters, a decent…
This talk is devoted to review the field of strangeness production in (ultra-)relativistic heavy ion collisions within our present theoretical understanding. Historically there have been (at least) three major ideas for the interest in the…
The role of Strangeness as a signal of the Quark Gluon Plasma in relativistic heavy ion experiments is discussed. The current experimental status is briefly presented. Several scenarios which explain the CERN data are discussed.
Within a chiral constituent quark formalism, allowing the inclusion of all known resonances, a comprehensive study of the recent eta photoproduction data on the proton up to 2 GeV is performed. This study shows evidence for a new S11…