Baryon resonances and polarization transfer in hyperon photoproduction

A partial-wave analysis of data on photoproduction of hyperons including single and double polarization observables is presented. The large spin transfer probability reported by the CLAS Collaboration can be successfully described within an isobar partial-wave analysis.     

Dipion decays of heavy baryons

Compared with the charmed baryons, the bottom baryons are not very well known, either experimentally or theoretically. In this paper, we investigate the dipion strong decays of the P-wave and D-wave excited bottom baryons in the framework of the QPC model. We also extend the same analysis to the charmed baryons.     

Recoil corrections to magnetic moments of charmed baryons in themit bag model

Recoil corrections to magnetic moments of charmed baryons are studied in themit bag model. It is noticed that such corrections which improve the octet baryon magnetic moments have considerably significant contributions to charmed baryon’s moments also.     

Interactions of charmed mesons with nucleons in the ¯<Emphasis Type="Italic">p</Emphasis><Emphasis Type="Italic">d</Emphasis> reaction

We study the possibility to measure the elastic ΦN (Φ≡J/ψ,ψ(2S), ψ(3770), χ_2c) scattering cross section in the reaction ˉp+d→Φ+n _sp and the elastic D(ˉD)N scattering cross section in the reaction ˉp+d→D ⁻ D ⁰ p _sp. Our studies indicate that the elastic scattering cross sections can be determined for Φ momenta about 4–6 GeV/c and D/ˉD momenta 2–5 GeV/c by selecting events with p _t≥ 0.4 GeV/c for Φ's and p _t(p _sp) ≥ 0.5 GeV/c for D/ˉD-meson production. Received: 8 November 1999     

Spectrum of b-baryons:color hyperfine interaction vs. experiment

I discuss several recent highly accurate theoretical predictions for masses of baryons containing the b quark, especially Ωb (ssb) very recently reported by CDF. I also point out an approximate effective supersymmetry between heavy quark baryons and mesons and provide predictions for the magnetic moments of Λc and Λb. Proper treatment of the color-magnetic hyperfine interaction in QCD is crucial for obtaining these results.     

π-J/ψ correlation and elliptic flow parameter v2 of charmed mesons at RHIC energy

We study the correlation between the trigger π and the associated J/ψ on near and away sides in Au+Au collisions at √SNN=200 GeV.In the region of trigger momentum Pt>4 GeV/c,the π spectrum is composed of thermal-shower and shower-shower recombinations in the frame work of the recombination model. We consider the azimuthal anisotropy in the quenched hard parton distribution and then calculate the elliptic flow parameter v<,2> of charmed mesons (J/ψ, D<'0> and D<,s>) for different centralities.     

Λc*in a coupled-channel baryon-meson scattering

Possible structures and properties of some excited states of Λc+dynamically generated in the coupled-channel P-wave meson-baryon scattering are studied by solving the Bethe-Salpeter(BS)equation in the framework of the Chiral Unitary Approach.It is shown that both Λc+(2765)and Λc+(2940)could be generated dynamically and could be compound states with multi-configuration molecular-like structures.The couplings of the generated states to various reaction channels are also calculated.Moreover,two highly excited states,Λc+(3024)and Λc+(3134),are predicted.     

A bag model study ofD mesons

An investigation of the newly discovered charmed mesonsD 0 andD +, particularly their non-leptonic decay modes, is carried out in the framework of the MIT bag model. The amplitude for a number of two-body final state decays are explicitly evaluated and compared with other available estimates.     

Lowest-lying spin-1/2 and spin-3/2 baryon magnetic moments in chiral perturbation theory

We review some recent progress in our understanding of the lowest-lying spin-1/2 and spin-3/2 baryon magnetic moments （MMs） in terms of Chiral Perturbation Theory （ChPT）.In particular,we show that at next-to-leading-order ChPT can describe the MMs of the octet baryons quite well.We also make predictions for the decuplet MMs at the same chiral order.Among them,the MMs of the Δ＋＋ and Δ ＋ are found to agree well with data within the experimental uncertainties.     

Dispersion theory relations and charmed baryon couplings

Dispersion theory sum rules proposed by Atkinson have been obtained for the invariant amplitudes of the elastic pion-charmed baryon scattering process. Saturating the sum rules with the known intermediate states, we obtain the pion-charmed baryon coupling constants.