669 research outputs found
The Zero-Point Field and Inertia
A brief overview is presented of the basis of the electromagnetic zero-point
field in quantum physics and its representation in stochastic electrodynamics.
Two approaches have led to the proposal that the inertia of matter may be
explained as an electromagnetic reaction force. The first is based on the
modeling of quarks and electrons as Planck oscillators and the method of
Einstein and Hopf to treat the interaction of the zero-point field with such
oscillators. The second approach is based on analysis of the Poynting vector of
the zero-point field in accelerated reference frames. It is possible to derive
both Newton's equation of motion, F=ma, and its relativistic co-variant form
from Maxwell's equations as applied to the zero-point field of the quantum
vacuum. This appears to account, at least in part, for the inertia of matter.Comment: 8 pages, no fig
Advances in the proposed electromagnetic zero-point field theory of inertia
A NASA-funded research effort has been underway at the Lockheed Martin
Advanced Technology Center in Palo Alto and at California State University in
Long Beach to develop and test a recently published theory that Newton's
equation of motion can be derived from Maxwell's equations of electrodynamics
as applied to the zero-point field (ZPF) of the quantum vacuum. In this
ZPF-inertia theory, mass is postulated to be not an intrinsic property of
matter but rather a kind of electromagnetic drag force that proves to be
acceleration dependent by virtue of the spectral characteristics of the ZPF.
The theory proposes that interactions between the ZPF and matter take place at
the level of quarks and electrons, hence would account for the mass of a
composite neutral particle such as the neutron. An effort to generalize the
exploratory study of Haisch, Rueda and Puthoff (1994) into a proper
relativistic formulation has been successful. Moreover the principle of
equivalence implies that in this view gravitation would also be electromagnetic
in origin along the lines proposed by Sakharov (1968). With regard to exotic
propulsion we can definitively rule out one speculatively hypothesized
mechanism: matter possessing negative inertial mass, a concept originated by
Bondi (1957) is shown to be logically impossible. On the other hand, the linked
ZPF-inertia and ZPF-gravity concepts open the conceptual possibility of
manipulation of inertia and gravitation, since both are postulated to be
electromagnetic phenomena. It is hoped that this will someday translate into
actual technological potential. A key question is whether the proposed
ZPF-matter interactions generating the phenomenon of mass might involve one or
more resonances. This is presently under investigation.Comment: Revised version of invited presentation at 34th AIAA/ASME/SAE/ASEE
Joint Propulsion Conference, July 13-15, 1998, Cleveland, OH, 10 pages, no
figure
Fusion of the -Vertex Operators and its Application to Solvable Vertex Models
We diagonalize the transfer matrix of the inhomogeneous vertex models of the
6-vertex type in the anti-ferroelectric regime intoducing new types of q-vertex
operators. The special cases of those models were used to diagonalize the s-d
exchange model\cite{W,A,FW1}. New vertex operators are constructed from the
level one vertex operators by the fusion procedure and have the description by
bosons. In order to clarify the particle structure we estabish new isomorphisms
of crystals. The results are very simple and figure out representation
theoretically the ground state degenerations.Comment: 35 page
Mass-Transport Models with Multiple-Chipping Processes
We study mass-transport models with multiple-chipping processes. The rates of
these processes are dependent on the chip size and mass of the fragmenting
site. In this context, we consider k-chip moves (where k = 1, 2, 3, ....); and
combinations of 1-chip, 2-chip and 3-chip moves. The corresponding mean-field
(MF) equations are solved to obtain the steady-state probability distributions,
P (m) vs. m. We also undertake Monte Carlo (MC) simulations of these models.
The MC results are in excellent agreement with the corresponding MF results,
demonstrating that MF theory is exact for these models.Comment: 18 pages, 4 figures, To appear in European Physical Journal
Determinant Representations of Correlation Functions for the Supersymmetric t-J Model
Working in the -basis provided by the factorizing -matrix, the scalar
products of Bethe states for the supersymmetric t-J model are represented by
determinants. By means of these results, we obtain determinant representations
of correlation functions for the model.Comment: Latex File, 41 pages, no figure; V2: minor typos corrected, V3: This
version will appear in Commun. Math. Phy
Some remarks on a generalization of the superintegrable chiral Potts model
The spontaneous magnetization of a two-dimensional lattice model can be
expressed in terms of the partition function of a system with fixed
boundary spins and an extra weight dependent on the value of a particular
central spin. For the superintegrable case of the chiral Potts model with
cylindrical boundary conditions, W can be expressed in terms of reduced
hamiltonians H and a central spin operator S. We conjectured in a previous
paper that W can be written as a determinant, similar to that of the Ising
model. Here we generalize this conjecture to any Hamiltonians that satisfy a
more general Onsager algebra, and give a conjecture for the elements of S.Comment: 18 pages, one figur
States insensitive to the Unruh effect in multi-level detectors
We give a general treatment of the spontaneous excitation rates and the
non-relativistic Lamb shift of constantly accelerated multi-level atoms as a
model for multi-level detectors. Using a covariant formulation of the dipole
coupling between the atom and the electromagnetic field we show that new
Raman-like transitions can be induced by the acceleration. Under certain
conditions these transitions can lead to stable ground and excited states which
are not affected by the non inertial motion. The magnitude of the Unruh effect
is not altered by multi-level effects. Both the spontaneous excitation rates
and the Lamb shift are not within the range of measurability.Comment: 9 Pages, late
Adjoint "quarks" on coarse anisotropic lattices: Implications for string breaking in full QCD
A detailed study is made of four dimensional SU(2) gauge theory with static
adjoint ``quarks'' in the context of string breaking. A tadpole-improved action
is used to do simulations on lattices with coarse spatial spacings ,
allowing the static potential to be probed at large separations at a
dramatically reduced computational cost. Highly anisotropic lattices are used,
with fine temporal spacings , in order to assess the behavior of the
time-dependent effective potentials. The lattice spacings are determined from
the potentials for quarks in the fundamental representation. Simulations of the
Wilson loop in the adjoint representation are done, and the energies of
magnetic and electric ``gluelumps'' (adjoint quark-gluon bound states) are
calculated, which set the energy scale for string breaking. Correlators of
gauge-fixed static quark propagators, without a connecting string of spatial
links, are analyzed. Correlation functions of gluelump pairs are also
considered; similar correlators have recently been proposed for observing
string breaking in full QCD and other models. A thorough discussion of the
relevance of Wilson loops over other operators for studies of string breaking
is presented, using the simulation results presented here to support a number
of new arguments.Comment: 22 pages, 14 figure
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Lepton + Jets Events with Lifetime b-tagging
We present a measurement of the top quark pair () production cross
section () in collisions at TeV
using 230 pb of data collected by the D0 experiment at the Fermilab
Tevatron Collider. We select events with one charged lepton (electron or muon),
missing transverse energy, and jets in the final state. We employ
lifetime-based b-jet identification techniques to further enhance the
purity of the selected sample. For a top quark mass of 175 GeV, we
measure pb, in
agreement with the standard model expectation.Comment: 7 pages, 2 figures, 3 tables Submitted to Phys.Rev.Let
Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt{s} = 1.96 TeV using Kinematic Characteristics of Lepton + Jets Events
We present a measurement of the top quark pair ttbar production cross section
in ppbar collisions at a center-of-mass energy of 1.96 TeV using 230 pb**{-1}
of data collected by the DO detector at the Fermilab Tevatron Collider. We
select events with one charged lepton (electron or muon), large missing
transverse energy, and at least four jets, and extract the ttbar content of the
sample based on the kinematic characteristics of the events. For a top quark
mass of 175 GeV, we measure sigma(ttbar) = 6.7 {+1.4-1.3} (stat) {+1.6- 1.1}
(syst) +/-0.4 (lumi) pb, in good agreement with the standard model prediction.Comment: submitted to Phys.Rev.Let
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