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.
119766377
Local and global performance of double-gap resistive plate chambers operated in avalanche mode
Two large double-gap resistive plate chambers, with 2 and 3 mm gap widths, were tested to study their response uniformity when operated in avalanche mode. The effects of mechanical tolerances and the presence of the spacers is thoroughly examined. Results on efficiency and time resolution are presented. We find that average performance and response uniformity over the whole chamber surface are fully adequate to the requirements of future collider experiments.
18438753
Brief physics survey with CMS in year one
The CMS detector is one of the two general purpose experiments that will study the collisions produced by the Large Hadron Collider (LHC). The LHC is supposed to start its operation in 2007 at an instantaneous luminosity of 2 x 10^33 cm-2 s-1, which may well result in an integrated luminosity of 10 fb-1 after the first year of running. The corresponding physics reach of CMS is exemplified with the study of a few standard model channels (weak boson and top quark production) and with the searches for Higgs bosons.
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.
60196961
Software for the CMS cosmic challenge
115001576
Single event effect measurements on the resistive plate chambers front-end chips for the CMS experiment
116993540
Latest results from the NA57 experiment
The NA57 experiment at the CERN SPS has measured the production of strange and multi‐strange particles in Pb‐Pb (and p‐Be) collisions at mid‐rapidity. The collective dynamics of the collision is studied in the transverse and longitudinal directions as a function of centrality and beam momentum and analysed on the basis of hydrodynamical models. Central‐to‐peripheral nuclear modification factors at 158 A GeV/c are presented and compared with other measurements and theory.
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.
59579158
Rapidity distributions of strange particles in Pb-Pb at 158 AGeV
The production at central rapidity of KS 0 , Λ , Ξ and Ω particles in Pb-Pb collisions at 158 AGeV has been measured by the NA57 experiment over a centrality range corresponding to the most central 53% of the inelastic Pb-Pb cross section. We present the rapidity distribution of each particle in the central rapidity unit. The distributions are analysed based on hydrodynamical models of the collisions.
166225720
Study of J / ψ production at central rapidity with the ALICE experiment at LHC
15825535
Blast-wave analysis of strange particle mT spectra in Pb–Pb collisions at the SPS
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