4,522 research outputs found
Electron identification performance with ALICE TRD prototypes
We present the electron/pion identification performance measured with
prototypes for ALICE TRD. Measured spectra of energy deposit of pions and
electrons as well as their average values are presented and compared to
calculations. Various radiators are investigated over the momentum range of 1
to 6 GeV/c. The time signature of TR is exploited in a bidimensional likelihood
mothod.Comment: Presented at the conference "TRDs for the 3rd millenium", Bari,
Italy, Sept. 4-7 2003. To appear in Nucl.Instrum.Meth. A. (4 pages, 6
figures
The Transition Radiation Detector for ALICE at LHC
The Transition Radiation Detector (TRD) for the ALICE experiment at the Large
Hadron Collider (LHC) identifies electrons in p+p and in the challenging high
multiplicity environment of heavy-ion collisions and provides fast online
tracking for the ALICE Level1 trigger. The TRD is designed to have excellent
position resolution and pion rejection capability. Presently, six of the 18 TRD
supermodules are installed in the ALICE central barrel. In 2008, four
supermodules were installed and commissioning of the detector using cosmic ray
tracks was successfully performed. We briefly describe the design of the
detector and report on the performance and current understanding of the
detector based on these data.Comment: 4 pages, 6 figures - To appear in the conference proceedings for
Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse
Experimental results and phenomenology of quarkonium production in relativistic nuclear collisions
An overview of recent measurements of quarkonium production in
nucleus-nucleus collisions and their understanding in theoretical models is
given.Comment: 8 pages, 7 figures; writeup of a plenary talk at Quark Matter 2014;
v2: final version (as published), with some rephrasing of tex
VOLUNTEER MANAGEMENT IN ROMANIA - AN EMERGING PRACTICE
Volunteering is a social practice still rare in Romania, despite the fact that it is an important component of non-governmental organizations; there are types of public organizations based on the contribution of volunteers and voluntary corporate initiatives. Regarding how the volunteers are included in non-governmental organizations, it is noteworthy that there are differences between how the activities are perceived by the volunteers and their supervisor; hence the importance of a volunteer management as a distinct form of human resources management in non-profit organizations.volunteering, organizational culture, volunteer management.
Charmonium and open charm production in nuclear collisions at SPS/FAIR energies and the possible influence of a hot hadronic medium
We provide predictions for charmonium and open charm production in nuclear
collisions at SPS/FAIR energies within the framework of the statistical
hadronization model. The increasing importance at lower energies of Lambda_c
production is demonstrated and provides a challenge for future experiments. We
also demonstrate that, because of the large charm quark mass and the different
timescales for charm quark and charmed hadron production, possible
modifications of charmed hadrons in the hot hadronic medium do not lead to
measurable changes in cross sections for D-meson production. A possible
influence of medium effects can be seen, however, in yields of charmonium.
These effects are visible at all energies and results are presented for the
energy range between charm threshold and RHIC energy.Comment: 12 pages, 4 figures; v2: slightly revised text and updated
calculations; v3: slightly enhanced discussion, one more ref.; data file with
calculations will be available at
http://www-linux.gsi.de/~andronic/physics/charm
The horn, the hadron mass spectrum and the QCD phase diagram - the statistical model of hadron production in central nucleus-nucleus collisions
We present the status of the description of hadron production in central
nucleus-nucleus collisions within the statistical model . The recent inclusion
of very high-mass resonances and the sigma meson leads to an improved
description of the data, in particular the energy dependence of the K+/pi+
ratio at SPS energies (``the horn''). The connection to the QCD phase diagram
is discussed.Comment: 4 pages, 3 figures; presented at the Nucleus-Nucleus 2009 conference,
Beijing, Aug. 200
Chemical freeze-out in heavy ion collisions at large baryon densities
We argue that the chemical freeze-out in heavy ion collisions at high baryon
density is not associated to a phase transition or rapid crossover. We employ
the linear nucleon-meson model with parameters fixed by the zero-temperature
properties of nuclear matter close to the liquid-gas quantum phase transition.
For the parameter region of interest this yields a reliable picture of the
thermodynamic and chiral properties at non-zero temperature. The chemical
freeze-out observed in low-energy experiments occurs when baryon densities fall
below a critical value of about 15 percent of nuclear density. This region in
the phase diagram is far away from any phase transition or rapid crossover.Comment: 8 pages, 11 figures, published versio
A Photon Peak due to Strong Coupling
We show that if a flavour-less vector meson remains bound after
deconfinement, and if its limiting velocity in the quark-gluon plasma is
subluminal, then this meson produces a distinct peak in the spectrum of thermal
photons emitted by the plasma. We also demonstrate that this effect is a
universal property of all strongly coupled, large-\nc plasmas with a gravity
dual. For the the corresponding peak lies between 3 and 5 GeV and
could be observed at the LHC.Comment: 4 pages, 2 figures - To appear in the conference proceedings for
Quark Matter 2009, March 30 - April 4, Knoxville, Tennessee. V2: minor
correction
Evidence for charmonium generation at the phase boundary in ultra-relativistic nuclear collisions
We investigate the transition from suppression to enhancement of J/psi mesons
produced in ultra-relativistic nuclear collisions in the framework of the
statistical hadronization model. The calculations are confronted with the most
recent data from the RHIC accelerator. This comparison yields first direct
evidence for generation of J/psi mesons at the phase boundary. Based on the
success of this approach we make specific predictions for LHC energy.Comment: 5 pages, 2 figures; final version accepted for publication in Phys.
Lett. B (Fig.1 containd a new set of calculations
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