16,698 research outputs found
Letter to Deanna Aamodt regarding SEAALL Annual Meeting, April 30, 2001
A letter from Catherine Lemann to Deanna Aamodt thanking Aamodt and West Group for exhibiting at the SEAALL Annual Meeting
SLIDES: Appropriate Sustainable Energy Technologies: A Light to the World
Presenter: Jason Aamodt, Attorney; Adjunct Professor, University of Tulsa
15 slide
Measurement of electrons from heavy-flavour decays in pp and Pb-Pb collisions with ALICE at the LHC
The ALICE experiment has measured at mid-rapidity electrons from
heavy-flavour decays in pp collisions at = 2.76 and 7 TeV, and in
Pb-Pb collisions at = 2.76 TeV. In pp collisions, electrons
from charm-hadron and from beauty-hadron decays are identified by applying cuts
on displaced vertices. The relative yield of electrons from beauty-hadron
decays to those from heavy-flavour decays is extracted using electron-hadron
correlations. Results are compared to pQCD-based calculations. In Pb-Pb
collisions, the dependence of the nuclear modification factor of
electrons from heavy-flavour decays is presented in two centrality classes. The
status on the analysis of electrons from beauty-hadron decays is reported in
Pb-Pb collisions, in view of the measurement of the corresponding nuclear
modification factor.Comment: 4 page, 5 figures, proceedings for the fifth International Conference
on Hard and Electromagnetic Probes of High Energy Nuclear Collisions (Hard
Probes 2012), May 27 - June 1, Cagliari, Ital
Physics with the ALICE experiment
ALICE experiment at LHC collects data in pp collisions at =0.9,
2.76 and 7 TeV and in PbPb collisions at 2.76 TeV. Highlights of the detector
performance and an overview of experimental results measured with ALICE in pp
and AA collisions are presented in this paper. Physics with proton-proton
collisions is focused on hadron spectroscopy at low and moderate .
Measurements with lead-lead collisions are shown in comparison with those in pp
collisions, and the properties of hot quark matter are discussed.Comment: Presented at the Conference of the Nuclear Physics Division of the
Russian Academy of Science, 11-25.11.2011, ITEP, Moscow. 16 pages, 14 figure
Charged particle production in Pb--Pb collisions at the LHC with the ALICE detector
The ALICE collaboration measured charged particle production in
TeV Pb--Pb collisions at the LHC. We report on results on
charged particle multiplicity and transverse momentum spectra. All the results
are presented as a function of the centrality of the collision, estimated with
a Glauber Monte Carlo fit to multiplicity distributions reconstructed in
various detectors. The applicability of the Glauber model at LHC energies, the
precision of the centrality determination and the related systematic
uncertainties are discussed in detail.
Particles are tracked in the pseudorapidity window \
with the silicon Inner Tracking System (ITS) and the Time Projection Chamber
(TPC), over the range 0.15 < \pt \lesssim 50 GeV/. The low- cut-off
is further reduced in the multiplicity measurement using "tracklets",
reconstructed in the 2 innermost layers of the ITS.
The charged particle multiplicity is measured in to be
in 5% most central Pb--Pb
collisions, indicating an energy density a factor higher than at RHIC.
Its evolution with centrality shows a pattern strikingly similar to the one
measured at RHIC. Intermediate (5 \lesssim \pt \lesssim 15 GeV/)
transverse momentum particles are found to be most strongly suppressed with
respect to pp collisions, consistent with a large energy loss of hard-scattered
partons in the hot and dense medium. The results are presented in terms of the
nuclear modification factor and compared to theoretical
expectations.Comment: 4 pages, 2 figures. Proceedings of the 5th international conference
on Hard and Electromagnetic Probes of High Energy Nuclear Collisions. Updated
version after referee report (minor changes
Correlations and fluctuations studied with ALICE
The measurement of particle correlations and event-by-event fluctuations of
physical observables allows to study a large variety of properties of the
matter produced in ultra relativistic heavy-ion collisions. We will present
results for two-particle correlations, mean transverse momentum fluctuations,
and net charge fluctuations in Pb-Pb collisions at 2.76 TeV.Comment: 7 pages, 5 figures, Proceedings submitted for the 28th Winter
Workshop on Nuclear Dynamics, Puerto Rico, April 7-14, 2012; corrected typo
First Results with Heavy-Ion Collisions at LHC from ALICE
In November 2010 the ALICE experiment at CERN has collected the first Pb--Pb
collisions at = 2.76 TeV produced by the LHC. A first
characterization of the hot and dense state of matter produced in this new
energy domain became available shortly after the run. In this paper we present
the results on charged-particle multiplicity, Bose-Einstein correlations,
elliptic flow and their dependence on the collision centrality. Results from
first measurements of strange and identified particle production and
suppression of high-momentum hadrons with respect to collisions are also
reported.Comment: 3 pages, 3 figures, PANIC 2011 Conferenc
Measurement of heavy-flavour production in proton-proton collisions at sqrt{s} = 7 TeV with ALICE
The measurement of the heavy-flavour production cross sections in pp
collisions at the LHC will allow to test perturbative QCD calculations in a new
energy domain. Moreover, within the physics program of the ALICE experiment, it
will provide the reference for the study of medium effects in Pb-Pb collisions,
where heavy quarks are regarded as sensitive probes of parton-medium
interaction dynamics. We present the status and first preliminary results of
charm and beauty production measurements with the ALICE experiment, using
hadronic D meson decays and semi-leptonic D and B meson decays, including the
first cross section measurement of muons from heavy flavour decays at forward
rapidity. We also describe the preliminary cross section measurement for J/psi
production, obtained using the di-electron decay channel at central rapidity
and the di-muon decay channel at forward rapidity.Comment: 8 pages, 5 figures, proceedings of the conference HARD PROBES 2010,
Eilat, October 201
Multiplicity and Underlying Event in ALICE: as measurements and as tools to probe QCD
With the high collision energies at the LHC, the contributions to particle
production from hard-QCD processes increase, but it remains dominated by
soft-QCD processes. Such processes challenge the theoretical models, since they
are described by non-perturbative phenomenology. A selection of the most recent
ALICE measurements of charged-particle multiplicities and the Underlying Event
will be presented, focusing on model comparisons. A summary of the current
understanding of soft-QCD processes will be discussed, evaluating possible ways
to further constrain theory.Comment: 4 pages, 3 figures, Rencontres de Moriond - QCD and high-energy
interaction
Pi0 and Eta measurement with photon conversions in ALICE in proton-proton collisions at sqrt(s) = 7 TeV
We present a measurement of the Pi0 transverse momentum spectrum and of the
Eta/Pi0 ratio in proton-proton collisions at sqrt(s) = 7 TeV at the CERN LHC.
In this analysis the reconstruction of Pi0 and Eta mesons has been done via
photon conversions in the central tracking system of ALICE. Therefore, this
method is completely independent from the electromagnetic calorimeters. It
makes the Pi0 (Eta) measurement possible down to pt = 0.4 (0.6) GeV/c with a
very good resolution and a very small background. For 100 Mio. pp collisions
the pt reach is 7 GeV/c. The results are compared to NLO pQCD calculations.Comment: Proceedings to talk at HardProbes 2010, 4 page
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