15,412 research outputs found
Approximate Zero Modes for the Pauli Operator on a Region
Let denoted the Pauli operator on a bounded open
region with Dirichlet boundary conditions and
magnetic potential scaled by some . Assume that the corresponding
magnetic field satisfies where and is an open subset of
of full measure (note that, the Orlicz space
contains for any ). Let
denote the corresponding eigenvalue counting function. We establish the strong
field asymptotic formula as , whenever
for some and . The
corresponding eigenfunctions can be viewed as a localised version of the
Aharonov-Casher zero modes for the Pauli operator on .Comment: 28 pages; for the sake of clarity the main results have been
reformulated and some minor presentational changes have been mad
DVCS with CLAS
Generalized parton distributions provide a unifying framework for the
interpretation of exclusive reactions at high . The most promising
reaction for the investigation of these distributions is the hard production of
photons using Deeply Virtual Compton Scattering (DVCS). This reaction can be
accessed experimentally by determining the production asymmetry using polarized
electrons on a proton target. Pioneering experiments with CLAS and HERMES have
produced the first measurements of this asymmetry. We will review the current
experimental program to study DVCS at Jefferson Lab. Recent high statistics
data taken with CLAS at 5.75 GeV allows us to determine this asymmetry at low
- in the valence region (=0.1-0.5) up to a of 4 GeV.Comment: 5 pages, 3 figures, Conference on the Intersections of Particle and
Nuclear Physics, New York City, May 19-24, 200
Review of Recent Jlab Results
High quality polarized electron beams at Jefferson Lab make possible
precision measurements of hadronic properties in the regime of strongly
interacting QCD. We will describe a few programs at Jefferson Lab that are
making measurements that link the basic static properties of hadrons to their
quark sub-structure. For example, parity-violating electron proton elastic
scattering probes the spatial distribution of strange quarks in the nucleon.
The nucleon-Delta transition form factors give us information about the
deformation of nucleons and Deltas. Finally, new high statistics measurements
of photons scattering off proton and deuteron targets are used to set upper
limits on the production of exotic baryons with strangeness S=+1. These
examples will be used to illustrate the capabilities and focus of the
experimental program at JLab.Comment: Contribution to XI International Conference on Hadron Spectroscopy, 4
figure
JLab: Probing Hadronic Physics with Electrons and Photons
Precision measurements of the structure of nucleons and nuclei in the regime
of strong interaction QCD are now possible with the availability of high
current polarized electron beams, polarized targets, and recoil polarimeters,
in conjunction with modern spectrometers and detector instrumentation. The
physics at JLab will be highlighted using two recent measurements of general
interest. The ratio of the proton electric to magnetic form factors indicates
the importance of the role of angular momentum in the structure of the nucleon.
The existence of 5-quark configurations in the ground state wavefunctions of
hadrons is confirmed by a narrow peak attributed to an exotic baryon with
strangeness S=+1. These and other examples will be used to illustrate the
capabilities and focus of the experimental program at JLab.Comment: V Latinamerican Symposium on Nuclear Physics, Santos, Brazil (Sept
1-5, 2003) 4 pages, 4 figure
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