64 research outputs found
Two-pion Bose-Einstein correlations in central Pb-Pb collisions at = 2.76 TeV
The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb
collisions at TeV at the Large Hadron Collider is
presented. We observe a growing trend with energy now not only for the
longitudinal and the outward but also for the sideward pion source radius. The
pion homogeneity volume and the decoupling time are significantly larger than
those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/388
Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at TeV
Inclusive transverse momentum spectra of primary charged particles in Pb-Pb
collisions at = 2.76 TeV have been measured by the ALICE
Collaboration at the LHC. The data are presented for central and peripheral
collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross
section. The measured charged particle spectra in and GeV/ are compared to the expectation in pp collisions at the same
, scaled by the number of underlying nucleon-nucleon
collisions. The comparison is expressed in terms of the nuclear modification
factor . The result indicates only weak medium effects ( 0.7) in peripheral collisions. In central collisions,
reaches a minimum of about 0.14 at -7GeV/ and increases
significantly at larger . The measured suppression of high- particles is stronger than that observed at lower collision energies,
indicating that a very dense medium is formed in central Pb-Pb collisions at
the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98
Effective Rheology of Bubbles Moving in a Capillary Tube
We calculate the average volumetric flux versus pressure drop of bubbles
moving in a single capillary tube with varying diameter, finding a square-root
relation from mapping the flow equations onto that of a driven overdamped
pendulum. The calculation is based on a derivation of the equation of motion of
a bubble train from considering the capillary forces and the entropy production
associated with the viscous flow. We also calculate the configurational
probability of the positions of the bubbles.Comment: 4 pages, 1 figur
Alignment of the ALICE Inner Tracking System with cosmic-ray tracks
37 pages, 15 figures, revised version, accepted by JINSTALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10^5 charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.Peer reviewe
A multicentre case control study on complicated coeliac disease: two different patterns of natural history, two different prognoses.
Abstract
Background: Coeliac disease is a common enteropathy characterized by an increased mortality mainly due to its
complications. The natural history of complicated coeliac disease is characterised by two different types of course:
patients with a new diagnosis of coeliac disease that do not improve despite a strict gluten-free diet (type A cases)
and previously diagnosed coeliac patients that initially improved on a gluten-free diet but then relapsed despite a
strict diet (type B cases). Our aim was to study the prognosis and survival of A and B cases.
Methods: Clinical and laboratory data from coeliac patients who later developed complications (A and B cases) and
sex- and age-matched coeliac patients who normally responded to a gluten-free diet (controls) were collected
among 11 Italian centres.
Results: 87 cases and 136 controls were enrolled. Complications tended to occur rapidly after the diagnosis of
coeliac disease and cumulative survival dropped in the first months after diagnosis of complicated coeliac disease.
Thirty-seven cases died (30/59 in group A, 7/28 in group B). Type B cases presented an increased survival rate
compared to A cases.
Conclusions: Complicated coeliac disease is an extremely serious condition with a high mortality and a short
survival. Survival depends on the type of natural history.
Keyword: Celiac disease, Complications, EATL, Prognosis, Glutens, Gluten-free die
Excavation works in stiff jointed clay material: examples from the Trubi formation, southern Italy
STRANGE PARTICLE-PRODUCTION IN SULFUR-SULFUR INTERACTIONS AT 200 GEV/C PER NUCLEON
The WA94 experiment is designed to study the production of strange and multistrange baryons and antibaryons in sulphur-sulphur interactions at 200 GeV/c per nucleon. The Omega spectrometer, equipped with MWPCs operated in the butterfly mode, is used to measure particles in the central rapidity window With PT > 1.0 Ge/V. Preliminary results are presented on the production of LAMBA, LAMBDABAR, XI- and XIBAR-
Charged particle production in S-S collisions at 200 GeV/c per nucleon
Charged particle production in central S-S collisions at 200 GeV/c per nucleon has been studied by the WA94 experiment at the CERN-SPS. Particle identification has been provided by the Omega RICH, while a silicon telescope in the Omega spectrometer and an array of MultiWire Proportional Chambers have been used to trace particles through the RICH detector. Production ratios and transverse mass spectra for pi(+/-), K+/- and p((p) over bar) at central rapidity and p(T) > 1.3 GeV/c are presented. (C) 1997 Elsevier Science B.V
Enhancement of strange and multi-strange hyperons and anti-hyperons in S-S and S-W interactions at 200 GeV/c
Strange and multistrange hyperon production is expected to be enhanced in heavy ion interactions if a phase transition from hadronic matter to a quark-gluon plasma takes place. The production yields of Lambda s, s, Xi(-)s, and (+)s relative to the production of negative particles are presented for p-W, p-S, S-W, and S-S interactions at 200 GeV/c per nucleon and compared to those from p-Pb and Pb-Pb interactions at 158 GeV/c per nucleon. In particular, enhancements of strange and multistrange hyperons will be presented where hyperon yields are normalized to the yields of negative particles
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