3,232 research outputs found
Baryon octupole moments
We report on a calculation of higher electromagnetic multipole moments of
baryons in a non-covariant quark model approach. The employed method is based
on the underlying spin-flavor symmetry of the strong interaction and its
breaking.We present results on magnetic octupole moments of decuplet baryons
and discuss their implications.Comment: 3 page
Highlights of Recent Results with Clas
Recent results on the study of the electromagnetic structure of nucleon
resonances, the spin structure of proton and neutrons at small and intermediate
photon virtualities, and the search for exotic pentaquark baryons are
presented.Comment: 12 pages, 8 figures, invited talk at MENU2004, Beijin
Outflanking and securely using the PIN/TAN-System
The PIN/TAN-system is an authentication and authorization scheme used in
e-business. Like other similar schemes it is successfully attacked by
criminals. After shortly classifying the various kinds of attacks we accomplish
malicious code attacks on real World Wide Web transaction systems. In doing so
we find that it is really easy to outflank these systems. This is even
supported by the users' behavior. We give a few simple behavior rules to
improve this situation. But their impact is limited. Also the providers support
the attacks by having implementation flaws in their installations. Finally we
show that the PIN/TAN-system is not suitable for usage in highly secure
applications.Comment: 7 pages; 2 figures; IEEE style; final versio
Dibaryon Condensate in Nuclear Matter and Neutron Stars: Exact Analysis in One-Dimensional Models
We investigate dense nuclear matter with a dibaryon Bose-Einstein condensate
as a possible intermediate state before the quark-gluon phase transition. An
exact analysis of this state of matter is presented in a one-dimensional model.
The analysis is based on a reduction of the quantization rules for the N-body
problem to N coupled algebraic transcendental equations. We observe that when
the Fermi momentum approaches the resonance momentum, the one-particle
distribution function increases near the Fermi surface. When the Fermi momentum
is increased beyond the resonance momentum, the equation of state becomes
softer. The observed behavior can be interpreted in terms of formation of a
Bose-Einstein condensate of two-fermion resonances (dibaryons). In cold nuclear
matter, it should occur if 2(m_N + epsilon_F) is greater or equal to m_D, where
m_N and m_D are respectively the nucleon and dibaryon masses and epsilon_F is
the nucleon Fermi energy.Comment: 25 pages, LaTeX, 2 Postscript figures, to appear in Annals of Physic
An Evaluated Certification Services System for the German National Root CA - Legally Binding and Trustworthy Transactions in E-Business and E-Government
National Root CAs enable legally binding E-Business and E-Government
transactions. This is a report about the development, the evaluation and the
certification of the new certification services system for the German National
Root CA. We illustrate why a new certification services system was necessary,
and which requirements to the new system existed. Then we derive the tasks to
be done from the mentioned requirements. After that we introduce the initial
situation at the beginning of the project. We report about the very process and
talk about some unfamiliar situations, special approaches and remarkable
experiences. Finally we present the ready IT system and its impact to
E-Business and E-Government.Comment: 6 pages; 1 figure; IEEE style; final versio
Intrinsic quadrupole moment of the nucleon
We address the question of the intrinsic quadrupole moment Q_0 of the nucleon
in various models. All models give a positive intrinsic quadrupole moment for
the proton. This corresponds to a prolate deformation. We also calculate the
intrinsic quadrupole moment of the Delta(1232). All our models lead to a
negative intrinsic quadrupole moment of the Delta corresponding to an oblate
deformation.Comment: 17 pages, 5 figure
Intrinsically Legal-For-Trade Objects by Digital Signatures
The established techniques for legal-for-trade registration of weight values
meet the legal requirements, but in praxis they show serious disadvantages. We
report on the first implementation of intrinsically legal-for-trade objects,
namely weight values signed by the scale, that is accepted by the approval
authority. The strict requirements from both the approval- and the
verification-authority as well as the limitations due to the hardware of the
scale were a special challenge. The presented solution fulfills all legal
requirements and eliminates the existing practical disadvantages.Comment: 4 pages, 0 figure
Spin of ground state baryons
We calculate the quark spin contribution to the total angular momentum of
flavor octet and flavor decuplet ground state baryons using a spin-flavor
symmetry based parametrization method of quantum chromodynamics. We find that
third order SU(6) symmetry breaking three-quark operators are necessary to
explain the experimental result Sigma_1=0.32(10). For spin 3/2 decuplet baryons
we predict that the quark spin contribution is Sigma_3=3.93(22), i.e.
considerably larger than their total angular momentum.Comment: 8 page
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