Hard form factors for meson-baryon strong couplings as derived from deep inelastic lepton scattering

As stimulated by earlier attempts for obtaining theNN andN form factors from the deep inelastic lepton scattering data, we extend the analysis by taking into account effects of additional mesons including, , ,K, andK ^*, with the coupling constants fixed by the lowenergy nucleon-nucleon and hyperon-nucleon scattering data. Contrary to an earlier claim that the NN andN form factor must be very soft (e.g., with the cutoff mass less than 500 MeV in the monopole form), we find, for example, that with all form factors parametrized in the dipole form, a universal cutoff mass of 1150 MeV in the/N sector and 1400 MeV in the/ sector yields predictions in excellent agreement with recently published neutrino data on the momentum fractions carried by thes, , and¯d quarks, as well as consistent with the sea-to-valence ratio extracted from the CDHS data and the Femilab E615 experiment. Similar results can also be obtained by using exponential cutoffs for all couplings, or by using monopole forms for some vertices while retaining dipole forms for the rest. The success of the mesonexchange picture in generating the strangeness content in a proton suggests an alternative understanding of the origin of sea quarks in the proton.We wish to thank G. Garvey, K. Holinde, L.-C. Liu, M. B. Johnson, M. Strikman, A. W. Thomas and Jochen Wambach for helpful conversations. W-Y. P. Hwang wishes to acknowledge the Alexander von Humboldt Foundation for a fellowship to visit Jülich for conducting research. His research works was also supported in part by the National Science Council of the Republic of China. The work of G. E. Brown is supported in part by a Humboldt award, in part by NATO Grant RG85/0093, and in part by the U.S. Department of Energy.     

Self-consistent calculations within the quasiparticle time blocking approximation with exact account taken of the single-particle continuum

A self-consistent version of the model based on the method of Green’s functions which takes into account conventional phonons of the random phase approximation, complex configurations like 2 quasiparticles?phonon ones, and exact single-particle continuum is used to describe many discrete natural-parity states and giant resonances in the ¹²³Sn and ²⁰⁸Pb nuclei. The quasiparticle-phonon interaction is shown to be important not only for low-lying and high-lying collective states but also for low-lying noncollective states.     

The effect of elastic forces on interface delocalization transitions

Elastic interaction prevents complete wetting and surface induced disordering and leads to a first order phase transition. The discontinuity is small for magnets and large for segregating binary alloys.     

Ground state correlations and electron scattering

The effect of random phase ground state correlations on charge densities and elastic electron scattering cross sections is studied for²⁰⁸Pb and⁴⁰Ca. Modifications of the charge densities relative to densities obtained by Hartree-Fock calculations with a density dependent force are studied using different RPA wave functions. The differences with respect to the HF charge distributions are discussed.