7281568
New results from the NA57 experiment
The production of hyperons in Pb–Pb and p–Be interaction at 40 A GeV/c beam momentum has been measured by the NA57 experiment. Strange particle enhancements at 40 A GeV/c are presented for the first time and compared to those measured at 158 A GeV/c. The transverse mass spectra of high statistics, high purity samples of K0S, Λ, Ξ and Ω particles produced in Pb–Pb collisions at 158 A GeV/c have been studied in the framework of the blast-wave model. The dependence of the freeze-out parameters on particle species and event centrality is discussed.
166225720
Study of J / ψ production at central rapidity with the ALICE experiment at LHC
119200364
NA57 main results
The CERN NA57 experiment was designed to study the production of strange and multi-strange particles in heavy-ion collisions at SPS energies; its physics programme is essentially completed. A review of the main results is presented.
16372397
First measurement of the strange particles R CP nuclear modification factors in heavy-ion collisions at the SPS
The NA57 experiment has measured the pT distributions of KSO, Λ, and \(\bar \Lambda \) particles in fixed-target Pb−Pb interactions at √sNN=17.3 GeV, as a function of the collision centrality. In this paper we study the central-to-peripheral nuclear modification factors and compare them to other measurements and to theoretical predictions.
119419969
Transverse mass distributions of strange particles produced in Pb-Pb collisions at 158 A GeV/c
Experiment NA57 has collected high statistics, high purity samples of $K^0_s$, $\Lambda$, $\Xi$ and $\Omega$ produced in Pb-Pb collisions at 158 $A$ GeV/$c$. In this paper we present a study of the transverse mass spectra of these particles for a sample of events corresponding to about the most central 55% of the inelastic Pb-Pb cross section. We analyse the transverse mass distributions in the framework of the blast-wave model for the full sample under consideration and, for the first time at the SPS, as a function of the event centrality.
121444459
Heavy flavours in ALICE
The ALICE experiment, currently in the commissioning phase, will study nucleus?nucleus and proton?proton collisions at the CERN large hadron collider (LHC). We review the ALICE heavy-flavour physics program and present a selection of results on the expected performance.
202110088
Search for resonances in the dijet mass spectrum from 7 TeV pp collisions at CMS
A search for narrow resonances with a mass of at least 1 TeV in the dijet mass spectrum is performed using pp collisions at root s = 7 TeV corresponding to an integrated luminosity of 1 fb(-1), collected by the CMS experiment at the LHC. No resonances are observed. Upper limits at the 95% confidence level are presented on the product of the resonance cross section, branching fraction into dijets, and acceptance, separately for decays into quark-quark, quark-gluon, and gluon-gluon pairs. The data exclude new particles predicted in the following models at the 95% confidence level: string resonances with mass less than 4.00 TeV, E-6 diquarks with mass less than 3.52 TeV, excited quarks with mass less than 2.49 TeV, axigluons and colorons with mass less than 2.47 TeV, and W' bosons with mass less than 1.51 TeV. These results extend previous exclusions from the dijet mass search technique. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.
121104721
Neutron irradiation of RPCs for the CMS experiment
All the CMS muon stations will be equipped with Resistive Plate Chambers (RPCs). They will be exposed to high neutron background environment during the LHC running. In order to verify the safe operation of these detectors, an irradiation test has been carried out with two RPCs at high neutron flux (about ), integrating values of dose and fluence equivalent to 10 LHC-years. Before and after the irradiation, the performance of the detectors was studied with cosmic muons, showing no relevant aging effects. Moreover, no indication of damage or chemical changes were observed on the electrode surfaces.
15045293
The bakelite for the RPCs of the experiment CMS
Results from aging tests on the bakelite used for the CMS RPCs are presented. Samples of melaminic bakelite were exposed to a heavy gamma and neutron radiation. Data on the bulk resistivity were collected while accumulating gamma and neutron doses and particles fluence up to values well beyond those expected in 10 years of RPCs operation in the barrel region of CMS. The test with gamma radiation was performed at the CERN Gamma Irradiation Facility (GIF) with a 20 Ci 137Cs source. A total absorbed dose of 5 Gy was accumulated during an irradiation period of about one month. The test with both neutron and gamma radiation was held at the Triga Mark II 250 kW reactor located in Pavia. A total of 80 h of exposure were accumulated integrating a neutron and gamma dose of about 80 Gy and a fast neutron fluence of some . Experimental data on dose rate in both the test facilities have been compared to simulation output and show a good agreement.
7845588
Resistive plate chambers in running and future experiments
This document surveys the RPC-based detection systems of running and future collider experiments focusing on the implications of the choice of some basic detector features: number of gaps, electrode material and operating mode. The muon identification systems of the B-factory experiments BaBar and Belle is described and the RPC performance since the first operation of the detectors is briefly reported. The trigger systems of the future LHC experiments ALICE, ATLAS and CMS are discussed and some results obtained in the research and development programs carried out by the Collaborations are reported.PACS: 29.40.Cs Resistive Plate Chambers; muon; trigger; RPC; ATLAS; ALICE; BaBar; Belle; CMS
121605998
Beam test results on double-gap resistive plate chambers proposed for CMS experiment
Resistive Plate Chambers were tested in a muon and pion beam to study the performances at different running conditions. Results on a first chamber built without the linseed oil treatment of the bakelite surfaces are presented together with an evaluation of the local effects due to the spacers. These results are extrapolated to the conditions expected at LHC.