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.
117970185
Search for pentaquarks in WA97 experiment at CERN
The WA97 experiment at CERN has collected data aiming to study strangeness production in heavy ion collisions at 158 A GeV/c; p‐Be data were also taken as reference data. Here we show some results of an analysis of these p‐Be data in order to check for evidence of a recently claimed pentaquark state.
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.
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.
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.
15830879
Centrality dependence of the expansion dynamics in Pb Pb collisions at 158-A-GeV/c
Two-particle correlation functions of negatively charged hadrons from Pb-Pb collisions at 158?GeV?c-1/nucleon have been measured by the WA97 experiment at the CERN SPS. A Coulomb correction procedure that assumes an expanding source has been implemented. Within the framework of an expanding thermalized source model the size and dynamical state of the collision fireball at freeze-out have been reconstructed as a function of the centrality of the collision. Less central collisions exhibit a different dynamics than central ones: both transverse and longitudinal expansion velocities are slower, the expansion duration is shorter and the system freezes out, showing smaller dimensions and higher temperature.
54732966
A Prototype front end chip for the CMS Resistive Plate Chambers
A new front-end amplifier-discriminator-monostable integrated circuit for the CMS Resistive Plate Chambers is presented. The aim of the circuit is to amplify current signals, ranging from 20 fC to 20 pC and generate output pulses having rise time as fast as possible for timing purposes. The full custom ASIC was designed and manufactured in the 0.8 μm BiCMOS technology by Austria Mikro Systeme.
209836136
First Measurement of the Cross Section for Top-Quark Pair Production in Proton-Proton Collisions at sqrt(s)=7 TeV
The first measurement of the cross section for top-quark pair production in pp collisions at the LHC at center-of-mass energy sqrt(s)= 7 TeV has been performed using 3.1 {pm} 0.3 inverse pb of data recorded by the CMS detector. This result utilizes the final state with two isolated, highly energetic charged leptons, large missing transverse energy, and two or more jets. Backgrounds from Drell-Yan and non-W/Z boson production are estimated from data. Eleven events are observed in the data with 2.1 {pm} 1.0 events expected from background. The measured cross section is 194 {pm} 72 (stat.) {pm} 24 (syst.) {pm} 21 (lumi.) pb, consistent with next-to-leading order predictions.
209834550
Measurement of the differential cross section for isolated prompt photon production in pp collisions at 7 TeV
A measurement of the differential cross section for the inclusive production of isolated prompt photons in proton-proton collisions at a centre-of-mass energy of 7 TeV is presented. The data sample corresponds to an integrated luminosity of 36 inverse picobarns recorded by the CMS detector at the LHC. The measurement covers the pseudorapidity range |eta|<2.5 and the transverse energy range 25 < ET < 400 GeV, corresponding to the kinematic region 0.007 < xT < 0.114. Photon candidates are identified with two complementary methods, one based on photon conversions in the silicon tracker and the other on isolated energy deposits in the electromagnetic calorimeter. The measured cross section is presented as a function of ET in four pseudorapidity regions. The next-to-leading-order perturbative QCD calculations are consistent with the measured cross section.
115001576
Single event effect measurements on the resistive plate chambers front-end chips for the CMS experiment
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.