We report the main results from experiment WA97 on the production of strange and multistrange hadrons at midrapidity in Pb+Pb, p+Pb and p+Be collisions at 158
A GeV/
c. A comparison with some of the ...available models is presented.
The ALICE High Level Trigger (HLT) is designed to perform event analysis of heavy ion and proton-proton collisions as well as calibration calculations online. A large PC farm, currently under ...installation, enables analysis algorithms to process these computationally intensive tasks. The HLT receives event data from all major detectors in ALICE. Interfaces to the various other systems provide the analysis software with required additional information. Processed results are sent back to the corresponding systems. To allow online performance monitoring of the detectors an interface for visualizing these results has been developed.
We present the performance of a full-length prototype of the ALICE Forward Calorimeter (FoCal). The detector is composed of a silicon-tungsten electromagnetic sampling calorimeter with longitudinal ...and transverse segmentation (FoCal-E) of about 20\(X_0\) and a hadronic copper-scintillating-fiber calorimeter (FoCal-H) of about 5\(\lambda_{\rm int}\). The data were taken between 2021 and 2023 at the CERN PS and SPS beam lines with hadron (electron) beams up to energies of 350 (300) GeV. Regarding FoCal-E, we report a comprehensive analysis of its response to minimum ionizing particles across all pad layers. The longitudinal shower profile of electromagnetic showers is measured with a layer-wise segmentation of 1\(X_0\). As a projection to the performance of the final detector in electromagnetic showers, we demonstrate linearity in the full energy range, and show that the energy resolution fulfills the requirements for the physics needs. Additionally, the performance to separate two-showers events was studied by quantifying the transverse shower width. Regarding FoCal-H, we report a detailed analysis of the response to hadron beams between 60 and 350 GeV. The results are compared to simulations obtained with a Geant4 model of the test beam setup, which in particular for FoCal-E are in good agreement with the data. The energy resolution of FoCal-E was found to be lower than 3% at energies larger than 100 GeV. The response of FoCal-H to hadron beams was found to be linear, albeit with a significant intercept that is about factor 2 larger than in simulations. Its resolution, which is non-Gaussian and generally larger than in simulations, was quantified using the FWHM, and decreases from about 16% at 100 GeV to about 11% at 350 GeV. The discrepancy to simulations, which is particularly evident at low hadron energies, needs to be further investigated.
Results from NA57 Dainese, A.
Nuclear physics. A,
08/2006, Letnik:
774
Journal Article
Recenzirano
Odprti dostop
The NA57 experiment has measured the production of strange and multi-strange hadrons in heavy-ion collisions at the CERN SPS. After briefly introducing the NA57 apparatus and analysis procedures, we ...present recent results on strangeness enhancement in Pb+Pb relative to p+Be collisions, on the study of the
m
T
distributions of strange particles, and on central-to-peripheral nuclear modification factors in Pb+Pb collisions at top SPS energy.
New results from the NA57 experiment Bruno, G E; Collaboration, the NA57
Journal of Physics G: Nuclear and Particle Physics,
08/2004, Letnik:
30, Številka:
8
Journal Article, Conference Proceeding
We present central-to-peripheral nuclear modification factors, RCP, for the pT distributions of KS0, Λ, Λ¯, and negatively charged particles, measured at central rapidity in Pb–Pb collisions at top ...SPS energy. The data cover the 55% most central fraction of the inelastic cross section. The KS0 and ΛRCP(pT) are similar in shape to those measured at sNN=200 GeV at RHIC, though they are larger in absolute value. We have compared our KS0RCP data to a theoretical calculation. The prediction overestimates the data at pT≈3–4 GeV/c, unless sizeable parton energy loss is included in the calculation.
The transverse mass spectra of high statistics, high purity samples of $K^{0}_{S}, \Lambda, \Xi and \Omega$ particles produced in Pb–Pb collisions at SPS energy have been studied in the framework of ...the blast-wave model. The dependence of the freezeout parameters on particle species and event centrality is discussed. Results at 40 A GeV/c are presented here for the first time
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