Search results for "ciência"
showing 10 items of 241 documents
Poly(alkylidenamines) dendrimers as scaffolds for the preparation of low-generation ruthenium based metallodendrimers
2011
The aim of this article is to highlight the use of nitrile-functionalized poly(alkylidenamines) dendrimers as building blocks for the preparation of low-generation ruthenium based cationic metallodendrimers having in view potential biomedical applications. Air-stable poly(alkylidenamines) nitrile dendrimers, peripherally functionalized with the ruthenium moieties [Ru(η5-C5H5)(PPh3)2]+ or [RuCl(dppe)2]+, have been prepared, characterized and are being studied for their anticancer activity. The followed strategy is based on the biological advantages associated with low-generation dendrimers, the known activity of ruthenium compounds as anticancer drugs and the stability of these dendrimers at…
Search for heavy long-lived charged particles with the ATLAS detector in pp collisions at root s=7 TeV
2011
A search for long-lived charged particles reaching the muon spectrometer is performed using a data sample of 37 pb[superscript −1] from pp collisions at √s = 7 TeV collected by the ATLAS detector at the LHC in 2010. No excess is observed above the estimated background. Stable [~ over τ] sleptons are excluded at 95% CL up to a mass of 136 GeV, in GMSB models with N[subscript 5] = 3, mmessenger = 250 TeV, sign(μ) = 1 and tanβ = 5. Electroweak production of sleptons is excluded up to a mass of 110 GeV. Gluino R-hadrons in a generic interaction model are excluded up to masses of 530 GeV to 544 GeV depending on the fraction of R-hadrons produced as [~ over g]-balls.
Search for new phenomena in final states with large jet multiplicities and missing transverse momentum using root s=7 TeV pp collisions with the ATLA…
2011
Results are presented of a search for any particle(s) decaying to six or more jets in association with missing transverse momentum. The search is performed using 1.34fb−1 of s √ s = 7 TeV proton-proton collisions recorded by the ATLAS detector during 2011. Data-driven techniques are used to determine the backgrounds in kinematic regions that require at least six, seven or eight jets, well beyond the multiplicities required in previous analyses. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a supersymmetry model (MSUGRA/CMSSM) where they extend previous constraints.
Search for dark matter candidates and large extra dimensions in events with a jet and missing transverse momentum with the ATLAS detector
2013
A search for new phenomena in events with a high-energy jet and large missing transverse momentum is performed using data from proton-proton collisions at √s = 7 TeV with the ATLAS experiment at the Large Hadron Collider. Four kinematic regions are explored using a dataset corresponding to an integrated luminosity of 4.7 fb[superscript −1]. No excess of events beyond expectations from Standard Model processes is observed, and limits are set on large extra dimensions and the pair production of dark matter particles.
Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS
2012
We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb[superscript −1] collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutral…
Measurement of $ZZ$ production in $pp$ collisions at $\sqrt{s}=7$ TeV and limits on anomalous $ZZZ$ and $ZZ\gamma$ couplings with the ATLAS detector
2013
Journal of High Energy Physics 2013.3 (2013): 128 reproduced by permission of Scuola Internazionale Superiore di Studi Avanzati (SISSA)
Search for massive long-lived highly ionising particles with the ATLAS detector at the LHC
2011
A search is made for massive highly ionising particles with lifetimes in excess of 100 ns, with the ATLAS experiment at the Large Hadron Collider, using 3.1 pb-1 of pp collision data taken at √s = 7TeV. The signature of energy loss in the ATLAS inner detector and electromagnetic calorimeter is used. No such particles are found and limits on the production cross section for electric charges 6e ≤ |q| ≤ 17e and masses 200 GeV ≤ m ≤ 1000 GeV are set in the range 1–12 pb for different hypotheses on the production mechanism.
Search for stable hadronising squarks and gluinos with the ATLAS experiment at the LHC
2011
Hitherto unobserved long-lived massive particles with electric and/or colour charge are predicted by a range of theories which extend the Standard Model. In this Letter a search is performed at the ATLAS experiment for slow-moving charged particles produced in proton–proton collisions at 7 TeV centre-of-mass energy at the LHC, using a data-set corresponding to an integrated luminosity of 34 pb[superscript −1]. No deviations from Standard Model expectations are found. This result is interpreted in a framework of supersymmetry models in which coloured sparticles can hadronise into long-lived bound hadronic states, termed R-hadrons, and 95% CL limits are set on the production cross-sections of…
Measurement of the cross section for top-quark pair production in pp collisions at √s = 7TeV with the ATLAS detector using final states with two high…
2012
A measurement is reported of the production cross section of top-quark pairs (tt¯) in proton-proton collisions at a center-of-mass energy of 7 TeV recorded with the ATLAS detector at the LHC. Candidate events have a signature consistent with containing two isolated leptons, large missing transverse momentum, and at least two jets. Using a data sample corresponding to an integrated luminosity of 0.70 fb−1, a tt¯ production cross section σtt¯=176±5(stat.)+14−11(syst.)±8(lum.) pb is measured for an assumed top-quark mass of mt = 172.5 GeV. This measurement is in good agreement with Standard Model predictions.
Search for charged Higgs bosons through the violation of lepton universality in t(t)over-bar events using pp collision data at root s=7 TeV with the …
2013
In several extensions of the Standard Model, the top quark can decay into a bottom quark and a light charged Higgs boson H [superscript +], t → bH [superscript +], in addition to the Standard Model decay t → bW. Since W bosons decay to the three lepton generations equally, while H [superscript +] may predominantly decay into τν, charged Higgs bosons can be searched for using the violation of lepton universality in top quark decays. The analysis in this paper is based on 4.6 fb[superscript −1] of proton-proton collision data at √s = 7 TeV collected by the ATLAS experiment at the Large Hadron Collider. Signatures containing leptons (e or μ) and/or a hadronically decaying τ (τ [subscript had])…