11,050 research outputs found
Strange and Multi-Strange Particle Production in ALICE
The production of strange and multi-strange hadrons in proton-proton (pp) and
lead-lead (Pb-Pb) collisions is studied with the ALICE experiment at the CERN
LHC. These particles are reconstructed via their weak decay topologies,
exploiting the tracking and particle identification capabilities of ALICE.
Measurements of central rapidity yields of ,  and
 baryons, their antiparticles and  mesons are
presented as a function of transverse momentum for Pb-Pb collisions at
 TeV. They are compared to those observed in pp collisions
as well as to results from lower energy nucleus-nucleus measurements.Comment: 4 pages, 3 figures, Hot Quarks 2012 Proceeding
Recovering pyramid WS gain in non-common path aberration correction mode via deformable lens
It is by now well known that pyramid based wavefront sensors, once in closed
loop, have the capability to improve more and more the gain as the reference
natural star image size is getting smaller on the pyramid pin. Especially in
extreme adaptive optics applications, in order to correct the non-common path
aberrations between the scientific and sensing channel, it is common use to
inject a certain amount of offset wavefront deformation into the DM(s),
departing at the same time the pyramid from the optimal working condition. In
this paper we elaborate on the possibility to correct the low order non-common
path aberrations at the pyramid wavefront sensor level by means of an adaptive
refractive lens placed on the optical path before the pyramid itself, allowing
the mitigation of the gain loss
Predicting economic market crises using measures of collective panic
Predicting panic is of critical importance in many areas of human and animal
behavior, notably in the context of economics. The recent financial crisis is a
case in point. Panic may be due to a specific external threat, or
self-generated nervousness. Here we show that the recent economic crisis and
earlier large single-day panics were preceded by extended periods of high
levels of market mimicry --- direct evidence of uncertainty and nervousness,
and of the comparatively weak influence of external news. High levels of
mimicry can be a quite general indicator of the potential for self-organized
crises.Comment: 17 pages, 4 figure
Nonextensive statistical effects in the hadron to quark-gluon phase transition
We investigate the relativistic equation of state of hadronic matter and
quark-gluon plasma at finite temperature and baryon density in the framework of
the nonextensive statistical mechanics, characterized by power-law quantum
distributions. We study the phase transition from hadronic matter to
quark-gluon plasma by requiring the Gibbs conditions on the global conservation
of baryon number and electric charge fraction. We show that nonextensive
statistical effects play a crucial role in the equation of state and in the
formation of mixed phase also for small deviations from the standard
Boltzmann-Gibbs statistics.Comment: 13 pages, 10 figure
Feature space analysis for human activity recognition in smart environments
Activity classification from smart environment data is typically done employing ad hoc solutions customised to the particular dataset at hand. In this work we introduce a general purpose collection of features for recognising human activities across datasets of different type, size and nature. The first experimental test of our feature collection achieves state of the art results on well known datasets, and we provide a feature importance analysis in order to compare the potential relevance of features for activity classification in different datasets
The Pierre Auger Observatory III: Other Astrophysical Observations
Astrophysical observations of ultra-high-energy cosmic rays with the Pierre
Auger ObservatoryComment: Contributions to the 32nd International Cosmic Ray Conference,
  Beijing, China, August 201
Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter
Data collected by the Pierre Auger Observatory through 31 August 2007 showed
evidence for anisotropy in the arrival directions of cosmic rays above the
Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{eV}. The
anisotropy was measured by the fraction of arrival directions that are less
than  from the position of an active galactic nucleus within 75 Mpc
(using the V\'eron-Cetty and V\'eron  catalog). An updated
measurement of this fraction is reported here using the arrival directions of
cosmic rays recorded above the same energy threshold through 31 December 2009.
The number of arrival directions has increased from 27 to 69, allowing a more
precise measurement. The correlating fraction is , compared
with  expected for isotropic cosmic rays. This is down from the early
estimate of . The enlarged set of arrival directions is
examined also in relation to other populations of nearby extragalactic objects:
galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in
hard X-rays by the Swift Burst Alert Telescope. A celestial region around the
position of the radiogalaxy Cen A has the largest excess of arrival directions
relative to isotropic expectations. The 2-point autocorrelation function is
shown for the enlarged set of arrival directions and compared to the isotropic
expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201
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