Results are presented on hyperon and antihyperon production in Pb–Pb, pPb and pBe collisions at 158 GeV/c per nucleon. Λ, Ξ and Ω yields have been measured at central rapidity and medium transverse ...momentum as functions of the centrality of the collision. Comparing the yields in Pb–Pb to those in pBe interactions, strangeness enhancement is observed. The enhancement increases with the centrality and with the strangeness content of the hyperons, reaching a factor of about 20 for the Ω in the central Pb–Pb collisions
A measurement of strange baryon and antibaryon production in Pb–Pb collisions has been carried out by the NA57 experiment at the CERN SPS, with 40 and 158 AGeV/c beam momentum. Results on Λ, Ξ and Ω ...hyperon yields at mid-rapidity in the most central 53% of Pb–Pb collisions at 40 AGeV/c are presented and compared with those obtained at higher energy, in the same collision centrality range.
The Λ and Ξ− yields per unit rapidity stay roughly constant while those of Ω−, Λ̄, Ξ̄+ and Ω̄+ increase when going to the higher SPS energy. Hyperon yields at the SPS are compared with those from the STAR experiment in sNN=130 GeV Au–Au collisions at RHIC.
ALICE (ALICE Collaboration 2008 JINST 3 S08002) is the LHC experiment mainly devoted to heavy-ion physics and to the quark-gluon plasma study. However, it has also excellent properties for pp physics ...at the unexplored energy regime available at LHC ( 14 TeV). Hadronic resonances play a fundamental role in the characterization of the strong interacting medium created in the collisions and can be sensitive to some expected QGP signatures like the chiral symmetry restoration and the strangeness enhancement. In this respect, a particularly important role is played by the (1020) resonance. The ability of ALICE to measure (1020) resonances by their K+K- decay has been investigated using simulated minimum bias PYTHIA events reconstructed with an implementation of the detector configuration (alignment, calibration, etc) which will be available for the first data. Its transverse momentum spectrum and its yield as a function of the charged event multiplicity have been evaluated with a statistics of some million of events. This shows how physics with resonances can be done right after the first high energy collisions at the LHC.
Combined tracking in the ALICE detector Badalà, A.; Barbera, R.; Lo Re, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2004, Letnik:
534, Številka:
1
Journal Article
Recenzirano
A neural network based algorithm to perform track recognition in the ALICE Inner Tracking System (ITS) for high transverse momentum particles
(
p
t
>
1
GeV
/
c
)
is presented. The model is based on ...the Denby–Peterson scheme, with some original improvements which are necessary to cope with the very high track density expected in ALICE. The application is used in combination with the standard tracking procedure for track reconstruction in ALICE in order to increase the efficiency, especially for rapidly decaying particles. Results are shown for a test performed simulating some central Pb–Pb events at 5.5
A
TeV in the center of mass system.
Neural tracking in the ALICE Inner Tracking System Pulvirenti, A.; Badalà, A.; Barbera, R. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2004, Letnik:
533, Številka:
3
Journal Article
Recenzirano
A neural network-based algorithm to perform track recognition in the ALICE Inner Tracking System (ITS) for high transverse momentum particles (pt>1GeV/c) is presented. The model is based on the ...Denby–Peterson scheme, especially improved to cope with the very high track density expected in ALICE. Results are shown for central and mid-central Pb–Pb collisions at the CERN Large Hadron Collider energy.
Recent test results of the ALICE silicon pixel detector Riedler, P.; Anelli, G.; Antinori, F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2005, Letnik:
549, Številka:
1
Journal Article
Recenzirano
The ALICE SPD (Silicon Pixel Detector) forms the two innermost layers of the Inner Tracking System (ITS) of the ALICE experiment at LHC. After several years of development the production of the ...modules is starting. The present article provides an overview of the different elements that will be used in the SPD with special emphasis given to testing of wafers and bump-bonded ladders.
Neural tracking in ALICE Badalà, A.; Barbera, R.; Lo Re, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2003, Letnik:
502, Številka:
2
Journal Article
Recenzirano
A neural network based algorithm to perform track recognition in the ALICE Inner Tracking System (ITS) for high transverse momentum particles (
p
t>1
GeV/c
) is presented,. The model is based on the ...Denby-Peterson scheme, with some original improvements which are necessary to cope with the very high track density expected in ALICE. Results are shown for a central Pb–Pb event at 5.5 A TeV in the center of mass system and the comparison with the Kalman Filter results is included.
The performance of the Inner Tracking System of the ALICE detector for primary vertex estimation is discussed. A simulation study of the vertex reconstruction in ALICE through the information given ...by the two pixel layers is reported. Vertex resolution was studied as a function of the nominal vertex location and of the particle multiplicity.
Tracking inside the ALICE Inner Tracking System Badalà, A.; Barbera, R.; Lo Re, G. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2002, Letnik:
485, Številka:
1
Journal Article
Recenzirano
Odprti dostop
One of the main purposes of the ALICE Inner Tracking System (ITS) is to improve the resolution of the track parameters found in the main ALICE tracker detector, the Time Projection Chamber (TPC). ...Some results about tracking efficiency and resolution of track parameters obtained with a tracking code, based on the Kalman filter algorithm, are presented.
The production at central rapidity of K0s, Lambda, Xi and Omega particles in Pb-Pb collisions at 158 A GeV/c has been measured by the NA57 experiment over a centrality range corresponding to the most ...central 53% of the inelastic Pb-Pb cross section. In this paper we present the rapidity distribution of each particle in the central rapidity unit as a function of the event centrality. The distributions are analyzed based on hydrodynamical models of the collisions.
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