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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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We study a model with partial quark-lepton universality that can naturally arise in grand unified theories. We find that constraints on the model can be reduced to a single condition on the Dirac CP phase δ in the neutrino sector. Using our current knowledge of the CKM and PMNS mixing matrices, we predict - 32 . 4 ° ≤ δ ≤ 32 . 0 ° at 2 σ .
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. Study of events with four or more leptons (electrons or muons) and missing transverse momentum in proton-proton collisions at a centre-of-mass energy of 7 TeV. The data were collected in 2011 and have an integrated total luminosity of 2.06 fb-1. Note that the additional requirements of missing ET > 50 GeV and a veto on the Z0 mass region, used in the analysis, is not applied in these tables, due to lack of statistics at those stages.
CERN-LHC. A search for gluinos decaying via the supersymmetric partner of the top (STOP) quark using events with two same-sign (SS) leptons, jets and missing transverse momentum. from proton-proton interactions at a centre-of-mass energy of 7 TeV. The data set has a total integrated luminosity og 2.05 fb-1. No excess beyond the SM is observed and exclusion limits are derived for simplified models where the gluino decays via the STOP and in the MSUGRA/CSSM framework. Data from the additional plots in the auxiliary material is also liniked here. In the distributions, where applicable: The errors on the DATA points represent the statistical uncertainty. The errors on the SM BACKGROUND represent the total uncertainty. The column labelled SIGNAL corresponds to a signal obtained with the decay gluino-> top stop chargino via off mass-shell stop (mass=1.2 TeV) in gluino-gluino pair-produced events with m(gluino)=650 GeV and m(chargino)=150 GeV.
CERN-LHC. A study of events in proton-proton collisions at a centre-of-mass energy of 7 TeV characterised by having large missing transverse momentum, jets and at least two tau leptons from a data sample of integrated luminosity 2 fb-1. The analysis finds no excesses above the Standard Model and presents lower limits on the GMSB breaking scale, Lambda, and the ratio of the vacuum expectation values of the two Higgs doublets, tan(beta). Data on the acceptances and efficiencies are given here taken from the auxilliary material linked below.
CERN-LHC. An interpretation of a search for supersymmetry in final states with four or more leptons (electrons or muons) and missing transverse momentum from proton-proton collisions at a centre-of-mass energy of 7 TeV. The anaylsis, based on an existing search reported in ATLAS-CONF-2012-001, uses a data sample with total integrated luminosity 2.06 fb-1 recorded in 2011, and finds no significant excess above the expectations from Standard Model processes. Exclusion limits are shown for mSUGRA/CMSSM with m0=A0=0, mu>0 and one R-parity violating parameter Lambda121=0.032 at the grand unification scane mGUT. This record lists the various limits with acceptances and efficiencies values and gives access to the SLHA files from the analyses.
Data from a search for the production of SUSY particles in proton-proton interactions at a centre of mass of 7 TeV using final states contianing jets, missing transverse momentum and at least one hadronically decaying tau lepton. The data, collected between March and April 2011, has a total integrated luminosity of 2.05 +- 0.08 fb-1. The trigger required at least one jet with PT > 75 GeV and missing PT > 45 GeV. As well as the numerical values of the plots in the paper, this record lists the acceptances, efficiences, and other signal data.
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. 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. Measurement of final states with four or more leptons (electrons or muons) produced in proton-proton collisions at a centre-of-mass energy of 7 TeV. The data sample has a total integrated luminosity of 4.7 fb-1. Comparisons with the Standard Model are made in two signal regions: one that requires moderate values of missing transverse momentum and the other that requires large effective mass. The data are interpreted in a simplified model of R-parity-vilaiting supersymmetry and in an R-partiy-violating MSUGRA/CMSSM model.
CERN-LHC. Search for direct pair production of heavy top-quark partners in proton-proton interactions of centre-of-mass energy of 7 TeV with a final state containing 2 leptons. The data sample taken during 2011 has a total integrated luminosity of 4.7 fb-1. Two models are compared with the data, one with a spin 1/.2 heavy top-quark and a heavy neutral partner and the other a supersymmetric scalar top quark and a massless neutralino. See the text of the paper for more details.
CERN-LHC. Measurements of the PHI* distributions of di-electron and di-muon Drell-Yan pairs produced in proton-proton collisions at a centre-of-mass energy of 7 TeV. The data sample has an integrated luminosity of 4.6 fb-1. Normalised differential PHI* distributions are presented within the fiducial region of the leptons corrected to three levels, Born, dressed and bare, for QED FSR. The data are presented for di-electron and di-muons separately as well as combined, and also in three regions of rapidity as well as overall. For details of the variables see the text of the article. UPDATE (05 JAN 2015): corrected columns 2,3,4 of Tables 2,3,5,6 due to a bug fixed for bare and dressed cross sections in y-ranges; Table 4, value of the very last bin of the born dimuon, y>1.6, phi*=2.522-3.277 corrected (typo error).
CERN-LHC. A search for the direct production of charginos and neutralinos in final states with three leptons and missing transverse momentum is presented. The analysis is based on 20.3 fb^-1 of sqrt(s) = 8 TeV proton--proton collision data delivered by the Large Hadron Collider and recorded in 2012 with the ATLAS detector. Observations are consistent with the Standard Model expectations and limits are set in R-parity-conserving phenomenological Minimal Supersymmetric Standard Models and in simplified supersymmetric models, significantly extending previous results. For simplified supersymmetric models of direct chargino (C1) and next-to-lightest neutralino (N2) production with decays to lightest neutralino (N1) via either all three generations of sleptons, staus only, gauge bosons, or Higgs bosons, C1 and N2 masses are excluded up to 700 GeV, 380 GeV, 345 GeV, or 148 GeV respectively, for a massless N1.
CERN-LHC. Searches for the electroweak production of charginos, neutralinos and sleptons in final states characterized by the presence of two leptons (electrons and muons) and missing transverse momentum are performed using 20.3 fb^-1 of proton-proton collision data at sqrt(s) = 8 TeV recorded in 2012 with the ATLAS experiment at the Large Hadron Collider. No significant excess beyond Standard Model expectations is observed. Limits are set on the masses of the lightest chargino, next-to-lightest neutralino and sleptons for different lightest-neutralino mass hypotheses in simplified models. Results are also interpreted in various scenarios of the phenomenological Minimal Supersymmetric Standard Model.
CERN-LHC. Results from a search for supersymmetry in events with four or more leptons including electrons, muons and taus are presented. The analysis uses a data sample corresponding to 20.3 fb^{-1} of proton-proton collisions delivered by the Large Hadron Collider at sqrt(s) = 8 TeV and recorded by the ATLAS detector. Signal regions are designed to target supersymmetric scenarios that can be either enriched in or depleted of events involving the production of a Z boson. No significant deviations are observed in data from Standard Model predictions and results are used to set upper limits on the event yields from processes beyond the Standard Model. Exclusion limits at the 95% confidence level on the masses of relevant supersymmetric particles are obtained. In R-parity-violating simplified models with decays of the lightest supersymmetric particle to electrons and muons, limits of 1350 GeV and 750 GeV are placed on gluino and chargino masses, respectively. In R-parity-conserving simplified models with heavy neutralinos decaying to a massless lightest supersymmetric particle, heavy neutralino masses up to 620 GeV are excluded. Limits are also placed on other supersymmetric scenarios.
CERN-LHC. A search is presented for direct top-squark pair production in final states with two leptons (electrons or muons) of opposite charge using 20.3 fb^-1 of pp collision data at sqrt(s) = 8 TeV, collected by the ATLAS experiment at the Large Hadron Collider in 2012. No excess over the Standard Model expectation is found. The results are interpreted under the separate assumptions (i) that the top squark decays to a b-quark in addition to an on-shell chargino whose decay occurs via a real or virtual W boson, or (ii) that the top squark decays to a t-quark and the lightest neutralino. A top squark with a mass between 150 GeV and 445 GeV decaying to a b-quark and an on-shell chargino is excluded at 95% confidence level for a top squark mass equal to the chargino mass plus 10 GeV, in the case of a 1 GeV lightest neutralino. Top squarks with masses between 215 (90) GeV and 530 (170) GeV decaying to an on-shell (off-shell) t-quark and a neutralino are excluded at 95% confidence level for a 1 GeV neutralino.
CERN-LHC. A generic search for anomalous production of events with at least three charged leptons is presented.
CERN-LHC. The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider (LHC) are reported.