2,750 research outputs found
Bilepton Production at Hadron Colliders
We examine, as model-independently as possible, the production of bileptons
at hadron colliders. When a particular model is necessary or useful, we choose
the 3-3-1 model. We consider a variety of processes: q anti-q -> Y^{++} Y^{--},
u anti-d -> Y^{++} Y^{-}, anti-u d -> Y^+ Y^{--}, q anti-q -> Y^{++} e^{-}
e^{-}, q anti-q -> phi^{++} phi^{--}, u anti-d -> -> phi^{++} phi^{-}, and
anti-u d -> phi^{+} phi^{--}, where Y and phi are vector and scalar bileptons,
respectively. Given the present low-energy constraints, we find that at the
Tevatron, vector bileptons are unobservable, while light scalar bileptons
(M_phi <= 300 GeV) are just barely observable. At the LHC, the reach is
extended considerably: vector bileptons of mass M_Y <= 1 TeV are observable, as
are scalar bileptons of mass M_phi <= 850 GeV.Comment: 20 pages (LATEX), 7 figures, minor modification
SOLUTIONS OF THE LANDAU-VLASOV EQUATION IN NUCLEAR PHYSICS
The properties of Vlasov equation solutions obtained by projection on coherent state basis are discussed. Such solutions satisfy stationarity conditions and satisfactorily describe the average diffusivity of nuclear phase space and reproduce the bulk properties of nuclei. Sampling methods and their effects on dynamics are discussed for the study of heavy ion reactions at intermediate energies. The non-local Gogny force is easily computable on this basis which allows to use it for dynamical nuclear studies
LOW AND INTERMEDIATE ENERGY HEAVY ION COLLISIONS IN THE SEMI-CLASSICAL MICROSCOPIC DESCRIPTION
It is shown how peripheral and central heavy-ion collisions can be described by Landau-Vlasov dynamics. For peripheral collisions at intermediate energies, mass-mass correlations, ejectile mean energies and angular distributions are obtained and compared with fragmentation data. For central collisions, one shows that the collision term destroys the TDHF property of transparency at low impact parameters for collisions close from the Coulomb barrier. Above 20 MeV/u incomplete fusion is described with associated linear momentum transfer and nuclear deformations. One exhibits how coupling to the continuum is obtained in Vlasov and Landau-Vlasov dynamics. Coulomb interaction being taken into account, we present also results concerning the isospin transfer and the excitation of the isovector dipole mode near and well above the Coulomb barrier. Some perspectives to further studies of physical observables are finally drawn
Customer Perception of Drive-Thru Service
The rapid growth of off-premise dining and, consequently, drive- thru service, presents the challenge of building customer loyalty in a highly competitive marketplace. In this study, customer perceptions of drive-thru service associated with quick service restaurants were examined. Results suggest that service time appears to differ among quick service restaurants, even those within the same chain. Employee courtesy was rated positively at all restaurants, as was food quality. The implications of these results for restaurateurs who offer drive-thru service are discussed
PHASE SPACE DYNAMICS OF HEAVY ION NUCLEAR COLLISIONS IN THE FERMI ENERGY DOMAIN
No abstract availabl
A STUDY ON THE FUSION REACTION 139La + 12C AT 50 MeV/u WITH THE VUU EQUATION
Recently Bownan et al. found that in the reaction 139La + 12C at 50 MeV/u a compound nucleus is formed. We simulate this reaction with a numerical solution of the VUU equation and indeed find that for a central collision the system fuses and equilibrates after 90 fm/c
Light-particle emission from the fissioning nuclei 126Ba, 188Pt and (266,272,278)/110: theoretical predictions and experimental results
We present a comparison of our model treating fission dynamics in conjunction
with light-particle (n, p, alpha) evaporation with the available experimental
data for the nuclei 126Ba, 188Pt and three isotopes of the element Z=110. The
dynamics of the symmetric fission process is described through the solution of
a classical Langevin equation for a single collective variable characterizing
the nuclear deformation along the fission path. A microscopic approach is used
to evaluate the emission rates for pre-fission light particles.
Entrance-channel effects are taken into account by generating an initial spin
distribution of the compound nucleus formed by the fusion of two deformed
nuclei with different relative orientations
Liquid-Drop Model and Quantum Resistance Against Noncompact Nuclear Geometries
The importance of quantum effects for exotic nuclear shapes is demonstrated.
Based on the example of a sheet of nuclear matter of infinite lateral
dimensions but finite thickness, it is shown that the quantization of states in
momentum space, resulting from the confinement of the nucleonic motion in the
conjugate geometrical space, generates a strong resistance against such a
confinement and generates restoring forces driving the system towards compact
geometries. In the liquid-drop model, these quantum effects are implicitly
included in the surface energy term, via a choice of interaction parameters, an
approximation that has been found valid for compact shapes, but has not yet
been scrutinized for exotic shapes.Comment: 9 pages with 3 figure
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