Charmed particle production in hadron-hadron collisions

In the framework of Quark-Gluon-String Model developed recently in ITEP we calculate spectra of charmed particlesD,D _s,Λ_c,Ξ_c,Ω_c in hadron-hadron collisions taking into account the decays ofS-wave resonances like D^*,D_s ^*,Σ_c,Σ_c ^*,Ξ_c ^*,Ξ_c ^′, and Ω_c ^*. We describe the bulk of the existing data onD, D^*, adΛ _c production in πp andpp collisions and predict the yield of charmed particlesin Σ^?p and Ξ^?p reactions at hyperon beam energies of 340 GeV/c and 600 GeV/c. Because of significant production of baryon resonances our predictions for unfavored fragmentation differ from predictions of other models which do not take resonance production into account.     

Shadow and antishadow effects in the scattering of particles on the deuteron

The shadow effects due to the inelastic rescattering of any incident particle on the nucleons of the deuteron are discussed. An empirical expression that takes into account the inelastic rescattering is proposed for the Glauber correction.     

Investigation of radioactivity in selected drinking water samples from Maryland

The comparator instrumental neutron activation analysis (INAA) method was used for certification of arsenic in Korea Research Institute of Standards and Science (KRISS) reference materials 108-04-001 (Oyster Tissue). The certified value was determined by analyzing one sample of approximately 0.15 g from ten bottles selected by random sampling. Potentially significant sources of uncertainty were taken into consideration using the guideline given by ISO. A complete evaluation of all sources of uncertainty yielded an expanded uncertainty for the mean value of this reference material of 4.7% at approximately 95% level of confidence.     

Binary reactions in $$\bar pp$$ collisions at intermediate energies

We discuss here the binary reactions of strange and charmed particle production in collisions at intermediate energies. In the case of baryon production with only one strange or charmed quark the cross section is determined by planar diagrams withK ^*,K ^** orD ^*,D ^**-meson poles in thet-channel. We calculated these diagrams in the frame of quark-gluon string model (QGSM) proposed earlier. We obtained also the cross-sections for reactions with baryon exchange in thet-channel with and pair in the final state. Predicted cross-sections for the reactions of production are of the order of hundred nanobarns. Using reggeon calculus we estimated cross-sections of binary reactions with two or three strange quarks in the final state: and . We discuss also the possible manifestation of color transparency effects in reactions with antiprotons on nuclei where all antiproton quarks annihilate.