0000000000587487
AUTHOR
A. Manousakis
showing 29 related works from this author
The optical instrumentation of the ATLAS Tile Calorimeter
2013
The purpose of this Note is to describe the optical assembly procedure called here Optical Instrumentation and the quality tests conducted on the assembled units. Altogether, 65 Barrel (or LB) modules were constructed - including one spare - together with 129 Extended Barrel (EB) modules (including one spare). The LB modules were mechanically assembled at JINR (Dubna, Russia) and transported to CERN, where the optical instrumentation was performed with personnel contributed by several Institutes. The modules composing one of the two Extended Barrels (known as EBA) were mechanically assembled in the USA, and instrumented in two US locations (ANL, U. of Michigan), while the modules of the oth…
Testbeam studies of production modules of the ATLAS Tile Calorimeter
2009
We report test beam studies of {11\,\%} of the production ATLAS Tile Calorimeter modules. The modules were equipped with production front-end electronics and all the calibration systems planned for the final detector. The studies used muon, electron and hadron beams ranging in energy from 3~GeV to 350~GeV. Two independent studies showed that the light yield of the calorimeter was $\sim 70$~pe/GeV, exceeding the design goal by {40\,\%}. Electron beams provided a calibration of the modules at the electromagnetic energy scale. Over 200~calorimeter cells the variation of the response was {2.4\,\%}. The linearity with energy was also measured. Muon beams provided an intercalibration of the respo…
Measurement of Inclusive Jet Cross Sections inZ/γ*(→e+e−)+jetsProduction inpp¯Collisions ats=1.96 TeV
2008
Inclusive jet cross sections in Z/{gamma}* events, with Z/{gamma}* decaying into an electron-positron pair, are measured as a function of jet transverse momentum and jet multiplicity in p{bar p} collisions at {radical}s - 1.96 TeV with the upgraded Collider Detector at Fermilab in Run II, based on an integrated luminosity of 1.7 fb{sup -1}. The measurements cover the rapidity region |y{sup jet}| 30 GeV/c. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross sections.
A layer correlation technique for pion energy calibration at the 2004 ATLAS Combined Beam Test
2010
A new method for calibrating the hadron response of a segmented calorimeter is developed and successfully applied to beam test data. It is based on a principal component analysis of energy deposits in the calorimeter layers, exploiting longitudinal shower development information to improve the measured energy resolution. Corrections for invisible hadronic energy and energy lost in dead material in front of and between the calorimeters of the ATLAS experiment were calculated with simulated Geant4 Monte Carlo events and used to reconstruct the energy of pions impinging on the calorimeters during the 2004 Barrel Combined Beam Test at the CERN H8 area. For pion beams with energies between 20GeV…
Strong Evidence forZZProduction inpp¯Collisions ats=1.96 TeV
2008
We report the first measurement of the cross section for Z boson pair production at a hadron collider. This result is based on a data sample corresponding to 1.9 fb{sup -1} of integrated luminosity from p{bar p} collisions at {radical}s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. In the {ell}{ell}{ell}{prime}{ell}{prime} channel, we observe three ZZ candidates with an expected background of 0.096{sub -0.063}{sup +0.092} events. In the {ell}{ell}{nu}{nu} channel, we use a leading-order calculation of the relative ZZ and WW event probabilities to discriminate between signal and background. In the combination of {ell}{ell}{ell}{prime}{ell}{prime} and {ell}{ell}{nu}{…
Measurement of thepp¯→tt¯production cross section and the top quark mass ats=1.96 TeVin the all-hadronic decay mode
2007
We report the measurements of the t{bar t} production cross section and of the top quark mass using 1.02 fb{sup -1} of p{bar p} data collected with the CDF II detector at the Fermilab Tevatron. We select events with six or more jets on which a number of kinematical requirements are imposed by means of a neural network algorithm. At least one of these jets must be identified as initiated by a b-quark candidate by the reconstruction of a secondary vertex. The cross section is measured to be {sigma}{sub t{bar t}} = 8.3 {+-} 1.0(stat. ){sup +2.0}{sub -1.5}(syst.) {+-} 0.5(lumi.) pb, which is consistent with the standard model prediction. The top quark mass of 174.0 {+-} 2.2(stat.){+-}4.8(syst.)…
Observation of Orbitally Excited Bs Mesons
2007
We report the first observation of two narrow resonances consistent with states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+, \bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1}) = 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.
Limits on anomalous triple gauge couplings inpp¯collisions ats=1.96 TeV
2007
We present a search for anomalous triple gauge couplings (ATGC) in WW and WZ boson production. The boson pairs are produced in p (p) over bar collisions at root s = 1.96 TeV, and the data sample corresponds to 350 pb(-1) of integrated luminosity collected with the CDF II detector at the Fermilab Tevatron. In this search one W decays to leptons, and the other boson (W or Z) decays hadronically. Combining with a previously published CDF measurement of W gamma boson production yields ATGC limits of -0.18 <lambda < 0.17 and -0.46 <Delta kappa < 0.39 at the 95% confidence level, using a cutoff scale Lambda=1.5 TeV.
Search for Maximal Flavor Violating Scalars in Same-Charge Lepton Pairs inpp¯Collisions ats=1.96 TeV
2009
Models of maximal flavor violation (MxFV) in elementary particle physics may contain at least one new scalar SU(2) doublet field {phi}{sub FV}=({eta}{sup 0},{eta}{sup +}) that couples the first and third generation quarks (q{sub 1}, q{sub 3}) via a Lagrangian term L{sub FV}={xi}{sub 13}{phi}{sub FV}q{sub 1}q{sub 3}. These models have a distinctive signature of same-charge top-quark pairs and evade flavor-changing limits from meson mixing measurements. Data corresponding to 2 fb{sup -1} collected by the Collider Dectector at Fermilab II detector in pp collisions at {radical}(s)=1.96 TeV are analyzed for evidence of the MxFV signature. For a neutral scalar {eta}{sup 0} with m{sub {eta}{sup 0}…
Search for the Higgs Boson in Events with Missing Transverse Energy andbQuark Jets Produced inpp¯Collisions ats=1.96 TeV
2008
We search for the standard model Higgs boson produced in association with an electroweak vector boson in events with no identified charged leptons, large imbalance in transverse momentum, and two jets where at least one contains a secondary vertex consistent with the decay of b hadrons. We use {approx}1 fb{sup -1} integrated luminosity of p{bar p} collisions at {radical}s = 1.96 TeV recorded by the CDF II experiment at the Tevatron. We find 268 (16) single (double) b-tagged candidate events, where 248 {+-} 43 (14.4 {+-} 2.7) are expected from standard model background processes. We place 95% confidence level upper limits on the Higgs boson production cross section for several Higgs boson ma…
Combined performance studies for electrons at the 2004 ATLAS combined test-beam
2010
In 2004 at the ATLAS (A Toroidal LHC ApparatuS) combined test beam, one slice of the ATLAS barrel detector (including an Inner Detector set-up and the Liquid Argon calorimeter) was exposed to particles from the H8 SPS beam line at CERN. It was the first occasion to test the combined electron performance of ATLAS. This paper presents results obtained for the momentum measurement p with the Inner Detector and for the performance of the electron measurement with the LAr calorimeter (energy E linearity and resolution) in the presence of a magnetic field in the Inner Detector for momenta ranging from 20 GeV/c to 100 GeV/c. Furthermore the particle identification capabilities of the Transition Ra…
The ATLAS hadronic tile calorimeter: From construction toward-physics
2005
ATLAS; The Tile Calorimeter, which constitutes the central section of the ATLAS hadronic calorimeter, is a non-compensating sampling device made of iron and scintillating tiles. The construction phase of the calorimeter is nearly complete, and most of the effort now is directed toward the final assembly and commissioning in the underground experimental hall. The layout of the calorimeter and the tasks carried out during construction are described, first with a brief reminder of the requirements that drove the calorimeter design. During the last few years a comprehensive test-beam program has been followed in order to establish the calorimeter electromagnetic energy scale, to study its unifo…
XIPE: the x-ray imaging polarimetry explorer
2016
XIPE, the X-ray Imaging Polarimetry Explorer, is a mission dedicated to X-ray Astronomy. At the time of writing XIPE is in a competitive phase A as fourth medium size mission of ESA (M4). It promises to reopen the polarimetry window in high energy Astrophysics after more than 4 decades thanks to a detector that efficiently exploits the photoelectric effect and to X-ray optics with large effective area. XIPE uniqueness is time-spectrally-spatially- resolved X-ray polarimetry as a breakthrough in high energy astrophysics and fundamental physics. Indeed the payload consists of three Gas Pixel Detectors at the focus of three X-ray optics with a total effective area larger than one XMM mirror bu…
Observation and Mass Measurement of the BaryonΞb−
2007
We report the observation and measurement of the mass of the bottom, strange baryon $\Xi^-_b$ through the decay chain $\Xi^-_b \to J/\psi \Xi^-$, where $J/\psi \to \mu^+ \mu^-$, $\Xi^- \to \Lambda \pi^-$, and $\Lambda \to p \pi^-$. Evidence for observation is based on a signal whose probability of arising from the estimated background is 6.6 x 10^{-15}, or 7.7 Gaussian standard deviations. The $\Xi^-_b$ mass is measured to be $5792.9\pm 2.5$ (stat.) $\pm 1.7$ (syst.) MeV/$c^2$.
Search for third generation vector leptoquarks inpp¯collisions ats=1.96 TeV
2008
We search for a third generation vector leptoquark (VLQ3) that decays to a b quark and tau lepton using the CDF II detector and 320pb-1 of integrated luminosity from the Fermilab Tevatron. Observing a number of events in agreement with standard model expectations, we obtain, assuming Yang-Mills (minimal) couplings, the most stringent upper limit on the VLQ3 pair production cross section of 344 fb (493 fb) and lower limit on the VLQ3 mass of 317GeV/c2 (251GeV/c2) at 95% C.L. © 2008 The American Physical Society.
Search for standard model Higgs bosons produced in association with W bosons.
2007
We report on the results of a search for standard model Higgs bosons produced in association with W bosons from p-pbar collisions at root s = 1.96 TeV. The search uses a data sample corresponding to approximately 1 fb-1 of integrated luminosity. Events consistent with the W to l-nu and H to b-bbar signature are selected by triggering on a high-pT electron or muon candidate and tagging one or two of the jet candidates as having originated from b quarks. A neural network filter rejects a fraction of tagged charm and light flavor jets, increasing the b-jet purity in the sample and thereby reducing the background to Higgs boson production. We observe no excess l-nu-b-bbar production beyond the …
Study of energy response and resolution of the ATLAS barrel calorimeter to hadrons of energies from 20 to 350 GeV
2010
A fully instrumented slice of the ATLAS detector was exposed to test beams from the SPS (Super Proton Synchrotron) at CERN in 2004. In this paper, the results of the measurements of the response of the barrel calorimeter to hadrons with energies in the range 20 to 350 GeV and beam impact points and angles corresponding to pseudorapidity values in the range 0.2-0.65 are reported. The results are compared to the predictions of a simulation program using the Geant 4 toolkit.
First measurement of the W-boson mass in run II of the Tevatron.
2007
7 pages, 4 figures.-- PACS nrs.: 14.70.Fm; 13.38.Be; 13.85.Qk.-- ISI Article Identifier: 000250140600014.-- ArXiv pre-print available at: http://arxiv.org/abs/0707.0085.-- et al.
Measurement of the cross section forW-boson production in association with jets inpp¯collisions ats=1.96 TeV
2008
We present a measurement of the cross section for W-boson production in association with jets in p{bar p} collisions at {radical}s = 1.96 TeV. The analysis uses a data sample corresponding to an integrated luminosity of 320 pb{sup -1} collected with the CDF II detector. W bosons are identified in their electron decay channel and jets are reconstructed using a cone algorithm. For each W + {ge} n-jet sample (n = 1-4) we measure {sigma}(p{bar p} {yields} W + {ge} n-jet) x {Beta}(W {yields} e{nu}) with respect to the transverse energy E{sub T} of the nth-highest E{sub T} jet above 20 GeV, for a restricted W {yields} e{nu} decay phase space. The cross sections, corrected for all detector effects…
Photon reconstruction in the ATLAS Inner Detector and Liquid Argon Barrel Calorimeter at the 2004 Combined Test Beam
2011
The reconstruction of photons in the ATLAS detector is studied with data taken during the 2004 Combined Test Beam, where a full slice of the ATLAS detector was exposed to beams of particles of known energy at the CERN SPS. The results presented show significant differences in the longitudinal development of the electromagnetic shower between converted and unconverted photons as well as in the total measured energy. The potential to use the reconstructed converted photons as a means to precisely map the material of the tracker in front of the electromagnetic calorimeter is also considered. All results obtained are compared with a detailed Monte-Carlo simulation of the test-beam setup which i…
First Measurement of Boson Production in Association with a Single Charm Quark in Collisions at
2008
The authors present the first measurement of the production cross section of a W boson with a single charm quark (c) in p{bar p} collisions at {radical}s = 1.96 TeV, using soft muon tagging of c jets. In a data sample of {approx} 1.8 fb{sup -1}, recorded with the CDF II detector at the Fermilab Tevatron, they select events with W + 1 or 2 jets. They use the charge correlation between the W and the muon from the semileptonic decay of a charm hadron to extract the We signal. They measure {sigma}{sub Wc} (p{sub Tc} > 20 GeV/c, |{eta}{sub c}| < 1.5) x BR(W {yields} {ell}{nu}) = 9.8 {+-} 3.2 pb, in agreement with theoretical expectations.
Study of the response of the ATLAS central calorimeter to pions of energies from 3 to 9 GeV
2009
Çetin, Serkant Ali (Dogus Author) A fully instrumented slice of the ATLAS central detector was exposed to test beams from the SPS (Super Proton Synchrotron) at CERN in 2004. In this paper, the response of the central calorimeters to pions with energies in the range between 3 and 9 GeV is presented. The linearity and the resolution of the combined calorimetry (electromagnetic and hadronic calorimeters) was measured and compared to the prediction of a detector simulation program using the toolkit Geant 4.
Measurement of pion and proton response and longitudinal shower profiles up to 20 nuclear interaction lengths with the ATLAS Tile calorimeter
2010
The response of pions and protons in the energy range of 20–180 GeV, produced at CERN's SPS H8 test-beam line in the ATLAS iron–scintillator Tile hadron calorimeter, has been measured. The test-beam configuration allowed the measurement of the longitudinal shower development for pions and protons up to 20 nuclear interaction lengths. It was found that pions penetrate deeper in the calorimeter than protons. However, protons induce showers that are wider laterally to the direction of the impinging particle. Including the measured total energy response, the pion-to-proton energy ratio and the resolution, all observations are consistent with a higher electromagnetic energy fraction in pion-indu…
Observation of Exclusive Dijet Production at the Fermilab Tevatron p-pbar Collider
2007
We present the first observation and cross section measurement of exclusive dijet production in pbar-p interactions, pbar + p --> pbar + dijet + p. Using a data sample of 310 pb-1 collected by the Run II Collider Detector at Fermilab at sqrt{s}=1.96 TeV, exclusive cross sections for events with two jets of transverse energy ET >= 10 GeV have been measured as a function of minimum ET(jet). The exclusive signal is extracted from fits to data distributions based on Monte Carlo simulations of expected dijet signal and background shapes. The simulated background distribution shapes are checked in a study of a largely independent data sample of 200 pb-1 of b-tagged jet events, where exclusi…
Search for chargino-neutralino production inpp¯collisions ats=1.96 TeVwith high-pTleptons
2007
We present a search for the associated production of charginos and neutralinos in pp collisions at s=1.96TeV. The data were collected at the Collider Detector at Fermilab (CDF II) and correspond to integrated luminosities between 0.7 and 1.0fb-1. We look for final states with one high-pT electron or muon, and two additional leptons. Our results are consistent with the standard model expectations, and we set limits on the cross section as a function of the chargino mass in three different supersymmetric scenarios. For a specific minimal supersymmetric standard model scenario with no slepton mixing, we set a 95% C.L. limit at 151GeV/c2. © 2008 The American Physical Society.
Search for new particles leading toZ+jetsfinal states inpp¯collisions ats=1.96 TeV
2007
We present the results of a search for new particles that lead to a Z boson plus jets in p{bar p} collisions at {radical}s = 1.96 TeV using the Collider Detector at Fermilab (CDF II). A data sample with a luminosity of 1.06 fb{sup -1} collected using Z boson decays to ee and {mu}{mu} is used. We describe a completely data-based method to predict the dominant background from standard-model Z+jet events. This method can be similarly applied to other analyses requiring background predictions in multi-jet environments, as shown when validating the method by predicting the background from W+jets in t{bar t} production. No significant excess above the background prediction is observed, and a limi…
Mechanical construction and installation of the ATLAS tile calorimeter
2013
This paper summarises the mechanical construction andinstallation of the Tile Calorimeter for the ATLASexperiment at the Large Hadron Collider in CERN, Switzerland. The TileCalorimeter is a sampling calorimeter using scintillator as the sensitivedetector and steel as the absorber and covers the central region of the ATLASexperiment up to pseudorapidities ±1.7. The mechanical construction ofthe Tile Calorimeter occurred over a periodof about 10 years beginning in 1995 with the completionof the Technical Design Report and ending in 2006 with the installationof the final module in the ATLAS cavern. Duringthis period approximately 2600 metric tons of steel were transformedinto a laminated struc…
Cross-section-constrained top-quark mass measurement from dilepton events at the tevatron
2008
We report the first top quark mass measurement that uses a cross section constraint to improve the mass determination. This measurement is made with a dilepton $t\bar{t}$ event sample collected with the CDF II detector. From a data sample corresponding to an integrated luminosity of 1.2 fb$^{-1}$, we measure a top quark mass of $\rm{170.7^{+4.2}_{-3.9}(stat)\pm2.6(syst)}$ $\rm{\pm2.4(theory) GeV/{\it{c}}^{2}}$. The measurement without the cross section constraint results in a top quark mass of $\rm{169.7^{+5.2}_{-4.9}(stat)\pm3.1(syst) GeV/{\it{c}}^{2}}$.
Search for doubly charged higgs bosons with lepton-rlavor-violating decays involving τ leptons
2008
We search for pair production of doubly charged Higgs particles (H(+/-+/-)) followed by decays into electron-tau (e tau) and muon-tau (mu tau) pairs using data (350 pb(-1)) collected from (p) over barp collisions at root s = 1.96 TeV by the CDF II experiment. We search separately for cases where three or four final-state leptons are detected, and combine results for exclusive decays to left-handed e tau (mu tau) pairs. We set an H(+/-+/-) lower mass limit of 114(112) GeV/c(2) at the 95% confidence level. RI Ruiz, Alberto/E-4473-2011; Robson, Aidan/G-1087-2011; De Cecco, Sandro/B-1016-2012; Prokoshin, Fedor/E-2795-2012; Azzi, Patrizia/H-5404-2012