Zobrazeno 1 - 10
of 59
pro vyhledávání: '"J. R. Shepard"'
Autor:
J R Shepard, H Müller
Publikováno v:
Journal of Physics G: Nuclear and Particle Physics. 26:1049-1064
Properties of heavy hypernuclei are studied in the context of a chiral Lagrangian which successfully describes ordinary nuclei. Λ-Σ0 mixing arises from non-diagonal vertices in flavour space induced by the vector mesons and by a phenomenological co
Autor:
Jorge Piekarewicz, J. R. Shepard
Publikováno v:
Physical Review B. 57:10260-10263
We employ the recently proposed plaquette basis to investigate static and dynamic properties of isotropic 2-leg Heisenberg spin ladders. Simple non-interacting multi-plaquette states provide a remarkably accurate picture of the energy/site and dynami
Autor:
Jorge Piekarewicz, J. R. Shepard
Publikováno v:
Physical Review B. 56:5366-5372
We employ a plaquette basis-generated by coupling the four spins in a $2\times2$ lattice to a well-defined total angular momentum-for the study of Heisenberg ladders with antiferromagnetic coupling. Matrix elements of the Hamiltonian in this basis ar
Autor:
Jeffrey D. Shafer, J. R. Shepard
Publikováno v:
Physical Review D. 55:4990-4996
We derive an approximate renormalization group (RG) flow equation for the local effective potential of single-component {phi}{sup 4} field theory at finite temperature. Previous zero-temperature RG equations are recovered in the low- and high-tempera
Publikováno v:
Zeitschrift für Physik C: Particles and Fields. 69:359-363
We verify the Goldstone theorem in the Gaussian functional approximation to theφ 4 theory with internalO(2) symmetry. We do so by reformulating the Gaussian approximation in terms of Schwinger-Dyson equations from which an explicit demonstration of
Publikováno v:
Physical Review D. 51:7017-7025
We study constraint effective potentials for various strongly interacting $\phi^4$ theories. Renormalization group (RG) equations for these quantities are discussed and a heuristic development of a commonly used RG approximation is presented which st
Autor:
Jorge Piekarewicz, J. R. Shepard
Publikováno v:
Physical Review C. 51:806-821
We formulate [ital K][sup +]-nucleus quasielastic scattering in a manner that closely parallels standard treatments of [ital e][sup [minus]]-nucleus quasielastic scattering. For [ital K][sup +] scattering, new responses involving scalar contributions
Autor:
T. Kishimoto, R. J. Peterson, L. Lee, B.L. Clausen, S. Bart, J. R. Shepard, Jorge Piekarewicz, R. Michael, R. E. Chrien, J.E. Wise, C.M. Kormanyos, M. B. Barakat
Publikováno v:
Physical Review Letters. 71:2571-2574
[ital K][sup +]-nucleus quasielastic cross sections measured for a laboratory kaon beam momentum of 705 MeV/[ital c] are presented for 3-momentum transfers of 300 and 500 MeV/[ital c]. The measured differential cross sections for C, Ca, and Pb at 500
Autor:
J. R. Shepard, Jorge Piekarewicz
Publikováno v:
Physical Review C. 45:2963-2974
We have calculated ground-state properties of hadronic matter in a mean-field approximation to a nontopological soliton model in one spatial dimension. The high-density phase of the model is a free Fermi gas of massless fermions. The low-density phas
Publikováno v:
Physical Review C. 45:1089-1097
We examine the random phase approximation (RPA) based on a relativistic Hartree approximation description for nuclear ground states. This model includes contributions from the negative energy sea at the one-loop level. We emphasize consistency betwee