Papers by Alejandro Thompson Sanchez
A search is presented for production of a heavy up-type quark (t ′ ) together with its antipartic... more A search is presented for production of a heavy up-type quark (t ′ ) together with its antiparticle, assuming subsequent decay to a W boson and a b quark, t ′t ′ → W + bW −b . The search is based on 1.04 fb −1 of proton-proton collisions at √ s = 7 TeV collected by the ATLAS detector at the CERN Large Hadron Collider. Data are analyzed in the lepton+jets final state, characterized by a high transverse momentum isolated electron or muon, high missing transverse momentum and at least three jets. No significant excess of events above the background expectation is observed. A 95% C.L. lower limit of 404 GeV is set for the mass of the t ′ quark.
This paper is dedicated to the memory of our ATLAS colleagues who did not live to see the full im... more This paper is dedicated to the memory of our ATLAS colleagues who did not live to see the full impact and significance of their contributions to the experiment.
Physics Letters B, 2012
A search for diphoton events with large missing transverse momentum has been performed using prot... more A search for diphoton events with large missing transverse momentum has been performed using proton-proton collision data at √ s = 7 TeV recorded with the ATLAS detector, corresponding to an integrated luminosity of 4.8 fb −1 . No excess of events was observed above the Standard Model prediction and model-dependent 95 % confidence level exclusion limits are set. In the context of a generalised model of gauge-mediated supersymmetry breaking with a bino-like lightest neutralino of mass above 50 GeV, gluinos (squarks) below 1.07 TeV (0.87 TeV) are excluded, while a breaking scale Λ below 196 TeV is excluded for a minimal model of gauge-mediated supersymmetry breaking. For a specific model with one universal extra dimension, compactification scales 1/R < 1.40 TeV are excluded. These limits provide the most stringent tests of these models to date.
A search is reported for the pair production of a new quark, b ′ , with at least one b ′ decaying... more A search is reported for the pair production of a new quark, b ′ , with at least one b ′ decaying to a Z boson and a bottom quark. The data, corresponding to 2.0 fb −1 of integrated luminosity, were collected from pp collisions at √ s = 7 TeV with the ATLAS detector at the CERN Large Hadron Collider. Using events with a b-tagged jet and a Z boson reconstructed from opposite-charge electrons, the mass distribution of large transverse momentum b ′ candidates is tested for an enhancement. No evidence for a b ′ signal is detected in the observed mass distribution, resulting in the exclusion at 95% confidence level of b ′ quarks with masses m b ′ < 400 GeV that decay entirely via b ′ → Z + b. In the case of a vector-like singlet b ′ mixing solely with the third Standard Model generation, masses m b ′ < 358 GeV are excluded. (c)
A search for direct pair production of supersymmetric top squarks (t 1 ) is presented, assuming t... more A search for direct pair production of supersymmetric top squarks (t 1 ) is presented, assuming thet 1 decays into a top quark and the lightest supersymmetric particle,χ 0 1, and that both top quarks decay to purely hadronic final states. A total of 16 (4) events are observed compared to a predicted Standard Model background of 13.5 + 3.7 − 3.6 (4.4 + 1.7 − 1.3 ) events in two signal regions based on L dt = 4.7 fb −1 of pp collision data taken at √ s = 7 TeV with the ATLAS detector at the LHC. An exclusion region in thet 1 versusχ 0 1 mass plane is evaluated: 370 < mt 1 < 465 GeV is excluded for mχ0 1 ∼ 0 GeV while mt 1 = 445 GeV is excluded for mχ0 1 ≤ 50 GeV. Technology, Ankara; (e)
European Physical Journal C, 2012
This paper presents a search for the t-channel exchange of an R-parity violating scalar top quark... more This paper presents a search for the t-channel exchange of an R-parity violating scalar top quark (t) in the e ± µ ∓ continuum using 2.1 fb −1 of data collected by the ATLAS detector in √ s = 7 TeV pp collisions at the Large Hadron Collider. Data are found to be consistent with the expectation from the Standard Model backgrounds. Limits on R-parity-violating couplings at 95% C.L. are calculated as a function of the scalar top mass (mt). The upper limits on the production cross section for pp → eµX, through the t-channel exchange of a scalar top quark, ranges from 170 fb for mt = 95 GeV to 30 fb for mt = 1000 GeV.
Edición digital, abril de 2000 LifeWay Christian Resources Nashville, Tennessee EL SEÑORIO DE CRI... more Edición digital, abril de 2000 LifeWay Christian Resources Nashville, Tennessee EL SEÑORIO DE CRISTO: UNA DEFINICION 8 EL SEÑORIÓ DE CRISTO: UNA DEFINICION 9 ara nosotros sin embargo, solo hay un Dios, el Padre, del cual proceden todas las cosas, y nosotros somos para él; y un Señor, Jesucristo, por medio del cual son todas las cosas y nosotros por medio de el (1 Co. &6).
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Papers by Alejandro Thompson Sanchez