37 research outputs found
Simulation of Light Antinucleus-Nucleus Interactions
Creations of light anti-nuclei (anti-deuterium, anti-tritium, anti-He3 and
anti-He4) are observed by collaborations at the LHC and RHIC accelerators. Some
cosmic ray experiments are aimed to find the anti-nuclei in cosmic rays. To
support the experimental studies of the anti-nuclei a Monte Carlo simulation of
anti-nuclei interactions with matter is implemented in the Geant4 toolkit. The
implementation combines practically all known theoretical approaches to the
problem of antinucleon-nucleon interactions.Comment: 8 pages, 5 figure
Peculiarities in produced particles emission in 208Pb + Ag(Br) interactions at 158 A GeV/c
The angular structures of particles produced in 208Pb induced collisions with
Ag(Br) nuclei in an emulsion detector at 158 A GeV/c have been investigated.
Nonstatistical ring-like substructures in azimuthal plane of the collision have
been found and their parameters have been determined. The indication on the
formation of the ring-like substructures from two symmetrical emission cones -
one in the forward and other in the backward direction in the center-of mass
system have been obtained. The ring-like substructures parameters have been
determined. The experimental results are in an agreement with I.M. Dremin idea,
that mechanism of the ring-like substructures formation in nuclear collisions
is similar to that of Cherenkov electromagnetic radiation.Comment: 10 pages, 7 figures, Report at the HADRON STRUCTURE'04 Conference,
Smolenice, Slovakia, 30.8.-3.9.200
Parton cascade description of relativistic heavy-ion collisions at CERN SPS energies ?
We examine Pb+Pb collisions at CERN SPS energy 158 A GeV, by employing the
earlier developed and recently refined parton-cascade/cluster-hadronization
model and its Monte Carlo implementation. This space-time model involves the
dynamical interplay of perturbative QCD parton production and evolution, with
non-perturbative parton-cluster formation and hadron production through cluster
decays. Using computer simulations, we are able to follow the entwined
time-evolution of parton and hadron degrees of freedom in both position and
momentum space, from the instant of nuclear overlap to the final yield of
particles. We present and discuss results for the multiplicity distributions,
which agree well with the measured data from the CERN SPS, including those for
K mesons. The transverse momentum distributions of the produced hadrons are
also found to be in good agreement with the preliminary data measured by the
NA49 and the WA98 collaboration for the collision of lead nuclei at the CERN
SPS. The analysis of the time evolution of transverse energy deposited in the
collision zone and the energy density suggests an existence of partonic matter
for a time of more than 5 fm.Comment: 16 pages including 7 postscript figure
Relativistic Heavy--Ion Collisions in the Dynamical String--Parton Model
We develop and extend the dynamical string parton model. This model, which is
based on the salient features of QCD, uses classical Nambu-Got\=o strings with
the endpoints identified as partons, an invariant string breaking model of the
hadronization process, and interactions described as quark-quark interactions.
In this work, the original model is extended to include a phenomenological
quantization of the mass of the strings, an analytical technique for treating
the incident nucleons as a distribution of string configurations determined by
the experimentally measured structure function, the inclusion of the gluonic
content of the nucleon through the introduction of purely gluonic strings, and
the use of a hard parton-parton interaction taken from perturbative QCD
combined with a phenomenological soft interaction. The limited number of
parameters in the model are adjusted to and -- data. Utilizing
these parameters, the first calculations of the model for -- and
-- collisions are presented and found to be in reasonable agreement with
a broad set of data.Comment: 26 pages of text with 23 Postscript figures placed in tex
Family psychosocial characteristics influencing criminal behaviour and mortality - possible mediating factors: a longitudinal study of male and female subjects in the Stockholm Birth Cohort
Serum levels of vitamin D, parathyroid hormone and calcium in relation to survival following breast cancer
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Cause of Death and Predictors of All-Cause Mortality in Anticoagulated Patients With Nonvalvular Atrial Fibrillation : Data From ROCKET AF
M. Kaste on työryhmän ROCKET AF Steering Comm jäsen.Background-Atrial fibrillation is associated with higher mortality. Identification of causes of death and contemporary risk factors for all-cause mortality may guide interventions. Methods and Results-In the Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation (ROCKET AF) study, patients with nonvalvular atrial fibrillation were randomized to rivaroxaban or dose-adjusted warfarin. Cox proportional hazards regression with backward elimination identified factors at randomization that were independently associated with all-cause mortality in the 14 171 participants in the intention-to-treat population. The median age was 73 years, and the mean CHADS(2) score was 3.5. Over 1.9 years of median follow-up, 1214 (8.6%) patients died. Kaplan-Meier mortality rates were 4.2% at 1 year and 8.9% at 2 years. The majority of classified deaths (1081) were cardiovascular (72%), whereas only 6% were nonhemorrhagic stroke or systemic embolism. No significant difference in all-cause mortality was observed between the rivaroxaban and warfarin arms (P=0.15). Heart failure (hazard ratio 1.51, 95% CI 1.33-1.70, P= 75 years (hazard ratio 1.69, 95% CI 1.51-1.90, P Conclusions-In a large population of patients anticoagulated for nonvalvular atrial fibrillation, approximate to 7 in 10 deaths were cardiovascular, whereasPeer reviewe