1,292 research outputs found
Leptogenesis with exclusively low-energy CP Violation in the Context of Minimal Lepton Flavour Violation
We analyze lepton flavour violation (LFV) and the generation of the observed
baryon-antibaryon asymmetry of the Universe (BAU) within a generalized minimal
lepton flavour violation framework with three quasi-degenerate heavy Majorana
neutrinos. The BAU which is obtained through radiative resonant leptogenesis
can successfully be generated widely independent of the Majorana scale in this
scenario and flavour effects are found to be relevant. Then we discuss the
specific case in which CP violation is exclusively present at low-energies (a
real R matrix) in the flavour sensitive temperature regime. Successful
leptogenesis in this case leads to strong constraints on low-energy neutrino
parameters.Comment: Contrubution to the proceedings of the EPS HEP 2007 conference,
Manchester (UK). 3 pages, 3 figure
Quadricuspid pulmonary valve complicated with aneurysm of pulmonary trunk diagnosed with ECG-gated computed tomography
Quadricuspid pulmonary valve (QPV) is an uncommon congenital defect reported
in the general population with a frequency of up to 0.25%. The defect
usually does not cause severe clinical complications and its presence frequently
remains clinically silent. Moreover, there are several difficulties in visualization
of pulmonary valve using basic diagnostic modalities such as echocardiography.
Therefore, in the majority of cases, QPV is detected accidentally during cardiac
procedures or post mortem.
The authors present a case of QPV complicated with aneurysm of the pulmonary
trunk, diagnosed with computed tomography in 70-year-old woman.
Although the patient had undergone transthoracic echocardiography examinations
several times in the past, only computed tomography allowed the detection
of the anomalous valve. In addition, the examination confirmed aneurysm
of the pulmonary trunk.
To the best of our knowledge, this is the first case of QPV diagnosed in vivo
with computed tomography
Arteria lusoria in patients with a normal and a right-sided aortic arch diagnosed with multi-slice computed tomography: a report of two cases
A retro-oesophageal course of the right subclavian artery is referred to as "arteria lusoria". It may be related to severe compression of the trachea and oesophagus, typically resulting in impaired swallowing. The paper presents two patients with arteria lusoria, which in one patient was an aberrant right subclavian artery and in the other an aberrant left subclavian artery, originating from the right-sided aortic arch. In both cases the diagnosis was made with multi-slice computed tomography. The embryology of the anomalies and clinical status of
the patients is discussed. Arteria lusoria should be considered in differential diagnosis in patients with dyspnoea and dysphagia. Multi-slice computed tomography allows this anatomical variant to be reliably visualised
Persistent trigeminal artery as a rare cause of ischaemic lesion and migraine-like headache
The persistent trigeminal artery (PTA) is a rare remnant of the embryonic intracranial circulatory system that forms a carotid-vertebrobasilar anastomosis. In most cases PTA does not have clear clinical implications. However, some authors report the association of PTA occurrence with vertigo, dizziness and nerve palsy, resulting in diplopia, strabismus or trigeminal neuralgia in patients. In rare cases it may also be related to posterior cerebral circulation strokes. This work reports the case of a female patient who presented with migraine-like headache and an ischaemic lesion in the left temporal lobe in association with PTA
Hemoglobin response to ferric citrate in patients with nondialysis-dependent chronic kidney disease and iron deficiency anemia
Evidence for a Soft Nuclear Equation-of-State from Kaon Production in Heavy Ion Collisions
The production of pions and kaons has been measured in Au+Au collisions at
beam energies from 0.6 to 1.5 AGeV with the Kaon Spectrometer at SIS/GSI. The
K+ meson multiplicity per nucleon is enhanced in Au+Au collisions by factors up
to 6 relative to C+C reactions whereas the corresponding pion ratio is reduced.
The ratio of the K+ meson excitation functions for Au+Au and C+C collisions
increases with decreasing beam energy. This behavior is expected for a soft
nuclear equation-of-state.Comment: 14 pages, 2 figures, accepted for publication in Phys. Rev. Let
Production of Charged Pions, Kaons and Antikaons in Relativistic C+C and C+Au Collisions
Production cross sections of charged pions, kaons and antikaons have been
measured in C+C and C+Au collisions at beam energies of 1.0 and 1.8 AGeV for
different polar emission angles. The kaon and antikaon energy spectra can be
described by Boltzmann distributions whereas the pion spectra exhibit an
additional enhancement at low energies. The pion multiplicity per participating
nucleon M(pi+)/A_part is a factor of about 3 smaller in C+Au than in C+C
collisions at 1.0 AGeV whereas it differs only little for the C and the Au
target at a beam energy of 1.8 AGeV. The K+ multiplicities per participating
nucleon M(K+)/A_part are independent of the target size at 1 AGeV and at 1.8
AGeV. The K- multiplicity per participating nucleon M(K-)/A_part is reduced by
a factor of about 2 in C+Au as compared to C+C collisions at 1.8 AGeV. This
effect might be caused by the absorption of antikaons in the heavy target
nucleus. Transport model calculations underestimate the K-/K+ ratio for C+C
collisions at 1.8 AGeV by a factor of about 4 if in-medium modifications of K
mesons are neglected.Comment: 19 pages, 14 figures, accepted for publication in Eur. Phys. J.
Dissolution in a field
We study the dissolution of a solid by continuous injection of reactive
``acid'' particles at a single point, with the reactive particles undergoing
biased diffusion in the dissolved region. When acid encounters the substrate
material, both an acid particle and a unit of the material disappear. We find
that the lengths of the dissolved cavity parallel and perpendicular to the bias
grow as t^{2/(d+1)} and t^{1/(d+1)}, respectively, in d-dimensions, while the
number of reactive particles within the cavity grows as t^{2/(d+1)}. We also
obtain the exact density profile of the reactive particles and the relation
between this profile and the motion of the dissolution boundary. The extension
to variable acid strength is also discussed.Comment: 6 pages, 6 figures, 2-column format, for submission to PR
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