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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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For the development of magnets for particle accellerators, the tool ROXIE from CERN has become a de facto standard. This script interprets the output files of ROXIE and translates them into a VTK file that can be read in ParaView for visualization.
We present results of the timing performance studies of the optical part and front-end electronics of the time-of-flight subdetector prototype for the ATLAS Forward Proton (AFP) detector obtained during the test campaigns at the CERN-SPS test-beam facility (120 GeV π + particles) in July 2016 and October 2016. The time-of-flight (ToF) detector in conjunction with a 3D silicon pixel tracker will tag and measure protons originating in central exclusive interactions p + p → p + X + p, where the two outgoing protons are scattered in the very forward directions. The ToF is required to reduce so-called pileup backgrounds that arise from multiple proton interactions in the same bunch crossing at high luminosity. The background can fake the signal of interest, and the extra rejection from the ToF allows the proton tagger to operate at the high luminosity required for the measurement of the processes. The prototype detector uses fused silica bars emitting Cherenkov radiation as a relativistic particle passes through them. The emitted Cherenkov photons are detected by a multi-anode micro-channel plate photomultiplier tube (MCP-PMT) and processed by fast electronics.
The High Luminosity upgrade of the CERN-LHC (HL-LHC) demands for a new high-radiation tolerant solid-state pixel sensor capable of surviving fluencies up to a few 10 16 particles/cm 2 at ~3 cm from the interaction point. To this extent the INFN ATLAS-CMS joint research activity, in collaboration with Fondazione Bruno Kessler-FBK, is aiming at the development of thin n-in-p type pixel sensors for the HL-LHC. The R&D covers both planar and single-sided 3D columnar pixel devices made with the Si-Si Direct Wafer Bonding technique, which allows for the production of sensors with 100 μm and 130 μm active thickness for planar sensors, and 130 μm for 3D sensors, the thinnest ones ever produced so far. The first prototypes of hybrid modules bump-bonded to the present CMS and ATLAS readout chips have been tested in beam tests. Furthermore, the preliminary results on their performance before and after irradiation are presented.
The High Luminosity upgrade of the CERN LHC collider (HL-LHC) demands a new high-radiation–tolerant solid-state pixel sensor capable of surviving fluencies up to a few 10$^{16} n_{eq}/\mathrm{cm}^2$ at ~ 3 cm from the interaction point. To this extent the INFN ATLAS-CMS joint research activity, in collaboration with Fondazione Bruno Kessler (FBK), is aiming at the development of thin n -in- p –type pixel sensors for the HL-LHC. The R&D covers both planar and single-sided 3D columnar pixel devices made with the Si-Si Direct Wafer Bonding technique, which allows for the production of sensors with 100 μm and 130 μm active thickness for planar sensors, and 130 μm for 3D sensors, the thinnest ones ever produced so far. The first prototypes of hybrid modules, bump-bonded to the present CMS readout chip, have been tested on beam. The first results on their performance before and after irradiation are presented
CERN-LHC. An inclusive search for SUSY in proton-proton collisions at a centre-of-mass energy of 7 TeV in final states with jets, missing transverse momentum and one or more isolated electron and/or muons. The search is based on data from the full 2011 data taking period with a total integrated luminosity of 4.7 fb-1. Single- and multi-lepton channels are treated together in the one analysis. The grid below gives access to the acceptance*efficiencies, 95% CLs, signal cross sections and number of generated events for 3 models, mSUGRA, GMSB and a simplified model with gluino pair production one-step decays.
CERN-LHC. Results of a search for narrow resonances in like-sign lepton pairs produced in proton-proton collisions at a centre-of-mass energy of 7 TeV using data with a total integrated luminosity of 4.7 fb-1. No significant excess is seen over Standard Model expectations and upper limits for the masses of doubly-charged Higgs bosons coupling to left- and right-handed fermions are determined as functions of their branching ratios to like-sign lepton pairs.
CERN-LHC. Search for new phenomena in events with a final state containing an energetic photon and large missing transverse momentum in proton-proton collisions at a centre-of-mass energy off 7 TeV. The data were collected during 2011 and have a total integrated luminosity of 4.6 fb-1. Agreement with Standard Model predictions is found to be good with an observed number of events in the data compared with a predicted number of 137.
CERN-LHC. Measurements of the event shape variables Transverse Thrust, Transverse Thrust Minor and Transverse Sphericity in proton-proton collisions at a centre-of-mass energy of 7 TeV. Events with at least six final state charged particles are selected from a data sample collected in April 2010 with a minimum prescale factor for the minimum-bias trigger. In addition to the event shape distributions, data on the evolution of their mean values with charged particle multiplicity and scalar PT sum are presented.
CERN-LHC. Measurements of the mean values and normalized distributions of multiplicity and transverse momentum of charged particles produced in final states containg on or more charged-particle jets in proton-proton interactions at a centre-of-mass energy of 7 TeV. The data sample used has a total integrated luminosity of 800 mub-1 with jets reconstructed using the anti-kt algorithm with radius parameter R varying between 0.2 and 1.0. The variables studied are the charged particle multiplcity, the scalar sum of the transverse momentum of charged particles and the average transverse momentum of the charged particles which equals the scalar sum divided by the multiplicity. Measurements are made separately in the regions opposite (AWAY) and transverse (TRANSVERSE) to the direction of the leading jet.
CERN-LHC. Study of events with final states comprising two opposite charge leptons, large missing transverse momentum and at least one jet in proton proton collisions at a centre-of-mass energy of 7 TeV. Uses the full 2011 data sample of 4.7fb-1. Data is given for the distributions of leading PT of the leptons and jets and of Missing ET for E-E, E-MU and MU-MU final states.
CERN-LHC. Measurements of the ratio, Rcp, between jet production in the central to peripheral regions in Lead Lead collisions at a centre of mass energy/nucleon of 2.76 TeV. Jets are reconstructed with |eta|<2.1, covering the jet PT range 38-210 GeV, using the anti-Kt algorithm with norminal jet radii of R=0.2, 0.3, 0.4 and 0.5. Seven regions of centrality are considered from the most peripheral of 60-80% to the most central 0-10%. Rcp is studied as a function of jet PT, number of participating nucleons NPART and R for each of the centrality regions, as well as the ratio of Rcp/Rcp(R=0.2) as a function of jet PT for each R=0.3, 0.4 and 0.5. Finally values of the covariance matrix for staistical correlations between jet PT bins are given. In the tables the first systematic errors are from JES, JER, efficiency, xin and Rcoll and are 100% correlated in PT. The second systematic errors are those that are partially correlated or uncorrelated in pt, taken to be 100% uncorrelated, from the regularization parameter.
CERN-LHC. Search for a heavy particle that decays to W+W- produced in proton-proton collisions at a centre-of-mass energy of 7 TeV using a data sample of integrated luminosity of 4.7 fb-1. Data are compared with standard model predictions and upper limits are set for Randall-Sundrum (SR) and bulk-RS graviton production.
CERN-LHC. Study of final states with at least six jets and large missing transverse energy from proton-proton interactions at a centre-of-mass energy of 7 TeV. The data sample with a total integrated luminosity of 4.7 fb-1 was collected during 2011. Events are required to have at least one jet with PT > 130 GeV and at least another five with PT > 30 GeV all within the pseudorapidity range -2.8-2.8. Two signal regions are defined one with missing ET > 150 GeV (SRA) and a second with missing ET > 260 GeV (SRB). Events with isolated electrons or muons are rejected. See the text of the paper for more details. The results are analysed in terms of direct pair production of supersymmetric top quarks (STOP_1) assuming their decay into a top quark and the lightest SUSY particle (LSP), a neutralino. Cross sections, Number of generated events, Acceptances and Efficiencies are presented here for both signal regions as functions of the STOP and NEUTRALINO masses.
CERN-LHC. Data are presented from the measurements of final states comprising three leptons (electrons or muons) and missing transverse energy in proton proton collisions at a centre-of-mass energy of 7 Tev. The data sample has a total integrated luminosity of 4.7fb-1 and is interpreted in the pMSSM and in simplified models using different signal regions. You are referred to the text of the paper for more details.
CERN-LHC. Measurements of the cross section for W+- plus Z0 production in proton proton collisions at a centre-of mass energy of 7 TeV. The data sample used, collected during 2011, has a total integrated luminosity of 4.6 fb-1 with 317 candidate events in the double leptonic decay final state with electrons, muons and missing transverse momentum. The total cross section is presented together with fiducial cross sections in a common phase space region.
CERN-LHC. A study of data from proton-proton collisions at a centre-of-mass energy of 7 TeV having final states consisting of one isolated electron or muon, jets and missing trasnverse momentum using a data sample of total integrated luminosity of 4.7 fb-1. Each event must have >=1 reconstructed primary vertex associated with five or more tracks with PT > 0.4 GeV. Events must have exactly one muon (or electron) with |eta|<2.4 (or 2.47) and pT > 20 (or 25) GeV and isolated from other particles. The scalar sum of the pT of tracks >1 GeV within a cone of size deltaR=0.2 around the lepton candidate is required to be < 10% of the electron pT, and <1.8 Gev for the muon. jets are reconstructed using the ant-kT clustering algorithm with radius parameter=0.4. Events with four or more jets with |eta|<2.5 and pT> 80,60,40,and 25 GeV are selected with at least one jet identified as a b-jet.
CERN-LHC. Study of high-mass lepton pairs (electron-positrons or muon-antimuons) produced in proton-proton collisions at a centre of mass energy of 7 TeV using data samples with integrated luminsoity of 4.9 fb-1 in the electron channel and 5.0 fb-1 in the muon channel. The results are interpreted in the search for the heavy boson resonances: heavy neutral Zprime gauge bosons, Randall-Sundrum gravitons, Z* bosons, techni-mesons, Kaluza-Klein Z/gamma bosons and bosons predicted by Torsion models.
CERN-LHC. Data from proton-proton interactions at a centre-of-mass energy of 7 TeV with a final state consisting of jets and missing transverse momentum and no high-pT electron or muons are interpreted in a number of SUSY model, listed in the table below.