33 research outputs found
Hadronic observables from SIS to SPS energies - anything strange with strangeness ?
We calculate and (+) rapidity
distributions and compare to experimental data from SIS to SPS energies within
the UrQMD and HSD transport approaches that are both based on string, quark,
diquark () and hadronic degrees of freedom. The
two transport models do not include any explicit phase transition to a
quark-gluon plasma (QGP). It is found that both approaches agree rather well
with each other and with the experimental rapidity distributions for protons,
's, and . Inspite of this apparent agreement both
transport models fail to reproduce the maximum in the excitation function for
the ratio found experimentally between 11 and 40 AGeV. A
comparison to the various experimental data shows that this 'failure' is
dominantly due to an insufficient description of pion rapidity distributions
rather than missing 'strangeness'. The modest differences in the transport
model results -- on the other hand -- can be attributed to different
implementations of string formation and fragmentation, that are not
sufficiently controlled by experimental data for the 'elementary' reactions in
vacuum.Comment: 46 pages, including 15 eps figures, to be published in Phys. Rev.
First measurement of θ<inf>13</inf> from delayed neutron capture on hydrogen in the Double Chooz experiment
The Double Chooz experiment has determined the value of the neutrino oscillation parameter θ13 from an analysis of inverse beta decay interactions with neutron capture on hydrogen. This analysis uses a three times larger fiducial volume than the standard Double Chooz assessment, which is restricted to a region doped with gadolinium (Gd), yielding an exposure of 113.1 GW-ton-years. The data sample used in this analysis is distinct from that of the Gd analysis, and the systematic uncertainties are also largely independent, with some exceptions, such as the reactor neutrino flux prediction. A combined rate- and energy-dependent fit finds sin22θ13=0.097±0.034 (stat.)±0.034 (syst.), excluding the no-oscillation hypothesis at 2.0. This result is consistent with previous measurements of sin22θ13
Atypical end-stage birdshot retinochoroidopathy
Purpose: To describe a patient with birdshot retinochoroidopathy with peripheral pigmentary changes mimicking a pseudoretinitis pigmentosa fundus. Case report: A 60-year-old female patient was referred for bilateral uveitis. Fundus examination showed several creamy lesions in the choroid of both eyes. The patient was HLA-A29-positive. A diagnosis of birdshot choroidopathy was made and she was treated with immunosupressive agents. Six years later, a pigmentation of the retina was noted in both eyes, which progressed to a bone-shaped appearance. Discussion: Pigmentary reaction is a common feature of retinal lesions, although it rarely takes on a retinitis pigmentosa-like appearance. Furthermore, birdshot fundus lesions do not usually become highly hyperpigmented even after long-term evolution. This pigmentation may represent one type of the end-stage of birdshot retinochoroidopathy.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Intensive immunosuppression treatment for central retinal vein occlusion in a young adult: A case report
Purpose: To describe a case of severe central retinal vein occlusion (CRVO) in a young patient, in whom intensive immunosuppressive therapy improved the clinical outcome. Case report: A 35-year-old men presented with a first episode of CRVO in his right eye in 1990. Despite corticosteroids and laser treatment, rubeotic glaucoma developed and the eye had to be enucleated. Seven years later, CRVO developed in the fellow eye, with venous tortuosity and haemorrhages. An extensive systemic workup was unremarkable. Corticosteroids failed to control the clinical situation. Cells were seen in the anterior vitreous. Visual acuity decreased to 2/60. Cyclosporine and azathioprine were added, but did not prevent recurrences. Campath-1H treatment was then started and visual acuity improved to 6/36. In November 2000, visual acuity was 6/24 and haemorrhages had cleared. Discussion: Many authors have proposed a role for inflammation in the pathophysiology of CRVO in young patients. However, there is no general agreement on corticosteroid use in these patients. Our case illustrates that, in some settings, high-dose corticosteroids and intensive immunosuppression might be used successfully to preserve vision.SCOPUS: ar.jinfo:eu-repo/semantics/publishe