No abstract available

[en] Results of calculations showing pre-threshold production of the W boson is possible. The responsible effect is illustrated by treating anti p production data with a realistic target nucleus model to show the presence of a production mechanism distinct from Fermi motion; the projectile collides collectively with more than one nucleon in the target. Such a production mechanism allows the W to be produced in nucleon-nucleus and nucleus-nucleus collisions at an energy well below that in nucleon-nucleon collisions

[en] Pion diffraction dissociation into the massive states KantiK*, NantiN, and YantiY is studied. The Reggeized Deck model leads to predictions for the occurrence of threshold enhancements in the sub-energies of such states produced in πN collisions. Generally good agreement with available data is seen, with that for the KantiK* being better than the data comparison for NantiN where the off-mass shell extrapolation distance is larger

[en] We study signatures of quark clusters in reactions which probe quarks in nuclei. We examine the EMC effect and use physical arguments to establish features of valence and ocean parton distributions in multiquark clusters. We predict from these distributions ratios of structure functions and cross sections measured with neutrino, antineutrinos and proton beams. It appears that a unique determination of the source of the EMC effect will be possible. 6 refs., 4 figs

No abstract available

[en] Within the QCD jet calculus formalism, we deduce an equation describing recombination of quarks and antiquarks into mesons within a quark or gluon jet. This equation relates the recombination function R(x₁,x₂,x) used in current literature to the fragmentation function for producing that same meson out of the parton initiating the jet. We submit currently used recombination functions to our consistency test, taking as input mainly the u-quark fragmentation data into π⁺ mesons, but also s-quark fragmentation into K^- mesons. The constraint is well satisfied at large Q² for large moments. Our results depend on one parameter, Q₀², the constraint equation being satisfied for small values of this parameter

No abstract available

[en] The authors present their calculations of fragmentation functions for quark and gluon breakup into two mesons within the jet calculus framework. The momentum fraction and Q/sup 2/ dependence of such two particle functions are presented and studied. The dependence on these variables is compared with the calculation by Willen who appends phenomenological fragmentation functions to the two parton jet calculus diagrams. Their approach requires all four parton diagrams. The Q/sup 2/ dependence of meson-meson correlations found by Willen are quite different from that in our approach and the two should be experimentally differentiated

[en] The existence of vector mesons with masses above 3 GeV suggests study of their contributions to the Compton sum rule. The Compton sum rule is used to place upper limits on photoproduction cross sections for such recently discovered and yet to be found J/sup p/ = 1^- particles. We are led to the result that the total proton photoabsorption cross section and forward Compton-scattering cross section will rise in the range of energies available for photon experiments at the Fermilab accelerator. Discussion is given on the implications of such a rising photon--proton cross section for vector-meson dominance (VMD), the quark model, generalized VMD, and the new duality, and for scaling breaking

No abstract available