974 research outputs found
Study of excited nucleon states at EBAC: status and plans
We present an overview of a research program for the excited nucleon states
in Excited Baryon Analysis Center (EBAC) at Jefferson Lab. Current status of
our analysis of the meson production reactions based on the unitary dynamical
coupled-channels model is summarized, and the N* pole positions extracted from
the constructed scattering amplitudes are presented. Our plans for future
developments are also discussed.Comment: Plenary talk given at Workshop on the Physics of Excited Nucleon --
NSTAR2009, Beijing, April 19-22, 2009. 8 pages, 8 figure
Recent developments in chiral dynamics of hadrons and hadrons in nuclei
In this talk I present recent developments in the field of hadronic physics
and hadrons in the nuclear medium. I review the unitary chiral approach to
meson baryon interaction and address the topics of the two dynamically
generated resonances, with experiments testing it, the
and resonances, plus the ,
and in the nuclear medium.Comment: 9 pages, 8 figures, Talk at YKIS06 Kyoto Symposium, Kyoto, december
200
High-precision measurement of the half-life of Ga
The beta-decay half-life of 62Ga has been studied with high precision using
on-line mass separated samples. The decay of 62Ga which is dominated by a 0+ to
0+ transition to the ground state of 62Zn yields a half-life of T_{1/2} =
116.19(4) ms. This result is more precise than any previous measurement by
about a factor of four or more. The present value is in agreement with older
literature values, but slightly disagrees with a recent measurement. We
determine an error weighted average value of all experimental half-lives of
116.18(4) ms.Comment: 9 pages, 5 figures, accepted for publication in PR
Magnetization structure of a Bloch point singularity
Switching of magnetic vortex cores involves a topological transition
characterized by the presence of a magnetization singularity, a point where the
magnetization vanishes (Bloch point). We analytically derive the shape of the
Bloch point that is an extremum of the free energy with exchange, dipole and
the Landau terms for the determination of the local value of the magnetization
modulus.Comment: 4 pages, 2 figure
Assessment of pulmonary antibodies with induced sputum and bronchoalveolar lavage induced by nasal vaccination against Pseudomonas aeruginosa: a clinical phase I/II study
<p>Abstract</p> <p>Background</p> <p>Vaccination against <it>Pseudomonas aeruginosa </it>is a desirable albeit challenging strategy for prevention of airway infection in patients with cystic fibrosis. We assessed the immunogenicity of a nasal vaccine based on the outer membrane proteins F and I from <it>Pseudomonas aeruginosa </it>in the lower airways in a phase I/II clinical trial.</p> <p>Methods</p> <p>N = 12 healthy volunteers received 2 nasal vaccinations with an OprF-OprI gel as a primary and a systemic (n = 6) or a nasal booster vaccination (n = 6). Antibodies were assessed in induced sputum (IS), bronchoalveolar lavage (BAL), and in serum.</p> <p>Results</p> <p>OprF-OprI-specific IgG and IgA antibodies were found in both BAL and IS at comparable rates, but differed in the predominant isotype. IgA antibodies in IS did not correlate to the respective serum levels. Pulmonary antibodies were detectable in all vaccinees even 1 year after the vaccination. The systemic booster group had higher IgG levels in serum. However, the nasal booster group had the better long-term response with bronchial antibodies of both isotypes.</p> <p>Conclusion</p> <p>The nasal OprF-OprI-vaccine induces a lasting antibody response at both, systemic and airway mucosal site. IS is a feasible method to non-invasively assess bronchial antibodies. A further optimization of the vaccination schedule is warranted.</p
On the background in the reaction and mixed event simulation
In this paper we evaluate sources of background for the , with the detected through its decay channel, to
compare with the experiment carried out at ELSA. We find background from
followed by decay of a into two ,
recombining one and one , and from the reaction with subsequent decay of the into two photons. This
background accounts for the data at invariant masses beyond 700
MeV, but strength is missing at lower invariant masses which was attributed to
photon misidentification events, which we simulate to get a good reproduction
of the experimental background. Once this is done, we perform an event mixing
simulation to reproduce the calculated background and we find that the method
provides a good description of the background at low invariant
masses but fakes the background at high invariant masses, making background
events at low invariant masses, which are due to misidentification
events, responsible for the background at high invariant masses which is due to
the and reactions.Comment: 10 pages, 5 figure
Dynamically generated resonances
In this talk I report on recent work related to the dynamical generation of
baryonic resonances, some made up from pseudoscalar meson-baryon, others from
vector meson-baryon and a third type from two meson-one baryon systems. We can
establish a correspondence with known baryonic resonances, reinforcing
conclusions previously drawn and bringing new light on the nature of some
baryonic resonances of higher mass.Comment: Talk given at the Workshop on physics of the excited nucleon-NSTAR
2009, Beijing, april 200
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