137 research outputs found
Parity-violating quasifree electron-deuteron scattering in a covariant approach
The role of relativistic corrections associated with lower Dirac components
of the deuteron wavefunction, is examined for parity-violating (PV) electron
scattering. The relation between these corrections and negative energy
components of the struck nucleon in relativistic PWIA is elucidated. The model
dependence induced by describing such effects, using different deuteron vertex
functions and prescriptions for the half-off-shell nucleon vertices, is
compared against the precision required for studies of nucleon strangeness in
quasielastic PV scattering.Comment: 18 pages, RevTeX, 14 figures using epsfig (included
Value migration: digitalization of shipping as a mechanism of industry dethronement
In this conceptual paper, we review latest developments related to unmanned vessels and sketch potential scenarios that implicate with the existing maritime industry structure. On the one hand, we isolate a range of challenges that make the imminent realization of unmanned vessels seem like a rather utopian pursuit. On the other hand, we explain the reasons that may catalyse their emergence. Inspired by these opposing tensions, we highlight that the digital transformation of the shipping industry has the potential to enhance value within the industryâs ecosystem. However, we also contend that unmanned vessels -if realized- pose a very particular threat to the identity of the shipping industry as we know it. In particular, we build upon the concept of value migration and we highlight the drastic existential changes that may likely stem from a shift to non-seafarer-centric shipping. We conclude with questions that matter for industry dethronement purposes i.e., the possibility that existing industry structures may be substantially reconfigured following a removal of the seafarer as the nucleus of value creation in shipping
N Delta - Transition Form Factors at Low Momentum Transfer
The three complex form factors entering the vertex
are calculated to in the framework of a chiral effective
theory with explicit (1232) degrees of freedom. Furthermore, the role
of presently unknown low energy constants that affect the values of EMR and CMR
is elucidated.Comment: 5 pages, 3 figures, Oral contribution given at the 8th International
Conference on the Structure of Baryons (Baryons '98), Bonn, Germany, Sept.
22-26, 199
Local Suppression and Splitting Techniques for Privacy Preserving Publication of Trajectories
postprin
Scaling and confinement aspects of tadpole improved SU(2) lattice gauge theory and its abelian projection
Using a tadpole improved SU(2) gluodynamics action, the nonabelian potential
and the abelian potential after the abelian projection are computed. Rotational
invariance is found restored at coarse lattices both in the nonabelian theory
and in the effective abelian theory resulting from maximal abelian projection.
Asymptotic scaling is tested for the SU(2) string tension. Deviation of the
order of is found, for lattice spacings between 0.27 and 0.06 fm. Evidence
for asymptotic scaling and scaling of the monopole density in maximal abelian
projection is also seen, but not at coarse lattices. The scaling behavior is
compared with analyses of Wilson action results, using bare and renormalized
coupling schemes. Using extended monopoles, evidence is found that the gauge
dependence of the abelian projection reflects short distance fluctuations, and
may thus disappear at large scales.Comment: 28 pages, RevTeX, 12 figures using epsfig (included); accepted for
publication in Physical Revie
Test of the QCD vacuum with the sources in higher representations
Recent accurate measurement by G.Bali of static potentials between sources in
various SU(3) representations provides a crucial test of the QCD vacuum and of
different theoretical approaches to the confinement. In particular, the Casimir
scaling of static potentials found for all measured distances implies a strong
suppression of higher cumulants and a high accuracy of the Gaussian stochastic
vacuum. Most popular models are in conflict with these measurements.Comment: LaTeX, 7 page
String breaking by dynamical fermions in three-dimensional lattice QCD
The first observation is made of hadronic string breaking due to dynamical
fermions in zero temperature lattice QCD. The simulations are done for SU(2)
color in three dimensions, with two flavors of staggered fermions. The results
have clear implications for the large scale simulations that are being done to
search (so far, without success) for string breaking in four-dimensional QCD.
In particular, string breaking is readily observed using only Wilson loops to
excite a static quark-antiquark pair. Improved actions on coarse lattices are
used, providing an extremely efficient means to access the quark separations
and propagation times at which string breaking occurs.Comment: Revised version to appear in Physical Review D, has additional
discussion of the results, additional references, modified title, larger
figure
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