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A. Di Girolamo

Bio: A. Di Girolamo is an academic researcher from CERN. The author has contributed to research in topics: Large Hadron Collider & Higgs boson. The author has an hindex of 11, co-authored 11 publications receiving 11368 citations. Previous affiliations of A. Di Girolamo include Universidade Federal de Juiz de Fora.

Papers
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Journal ArticleDOI
Georges Aad1, T. Abajyan2, Brad Abbott3, Jalal Abdallah4  +2964 moreInstitutions (200)
TL;DR: In this article, a search for the Standard Model Higgs boson in proton-proton collisions with the ATLAS detector at the LHC is presented, which has a significance of 5.9 standard deviations, corresponding to a background fluctuation probability of 1.7×10−9.

9,282 citations

Journal ArticleDOI
Morad Aaboud, Georges Aad1, Brad Abbott2, Jalal Abdallah3  +2845 moreInstitutions (197)
TL;DR: This paper presents a short overview of the changes to the trigger and data acquisition systems during the first long shutdown of the LHC and shows the performance of the trigger system and its components based on the 2015 proton–proton collision data.
Abstract: During 2015 the ATLAS experiment recorded 3.8 fb(-1) of proton-proton collision data at a centre-of-mass energy of 13 TeV. The ATLAS trigger system is a crucial component of the experiment, respons ...

488 citations

Journal ArticleDOI
Georges Aad1, Brad Abbott2, Jalal Abdallah3, Ovsat Abdinov4  +2828 moreInstitutions (191)
TL;DR: In this article, the performance of the ATLAS muon identification and reconstruction using the first LHC dataset recorded at s√ = 13 TeV in 2015 was evaluated using the Monte Carlo simulations.
Abstract: This article documents the performance of the ATLAS muon identification and reconstruction using the first LHC dataset recorded at s√ = 13 TeV in 2015. Using a large sample of J/ψ→μμ and Z→μμ decays from 3.2 fb−1 of pp collision data, measurements of the reconstruction efficiency, as well as of the momentum scale and resolution, are presented and compared to Monte Carlo simulations. The reconstruction efficiency is measured to be close to 99% over most of the covered phase space (|η| 2.2, the pT resolution for muons from Z→μμ decays is 2.9% while the precision of the momentum scale for low-pT muons from J/ψ→μμ decays is about 0.2%.

440 citations

Journal ArticleDOI
Georges Aad1, Brad Abbott2, Jalal Abdallah3, S. Abdel Khalek4  +2911 moreInstitutions (209)
TL;DR: In this paper, a measurement of the Z/gamma* boson transverse momentum spectrum using ATLAS proton-proton collision data at a centre-of-mass energy of root s = 7TeV at the LHC is described.
Abstract: This paper describes a measurement of the Z/gamma* boson transverse momentum spectrum using ATLAS proton-proton collision data at a centre-of-mass energy of root s = 7TeV at the LHC. The measurement is performed in the Z/gamma* -> e(+)e(-) and Z/gamma* -> mu(+)mu(-) channels, using data corresponding to an integrated luminosity of 4.7 fb(-1). Normalized differential cross sections as a function of the Z/gamma* boson transverse momentum are measured for transverse momenta up to 800 GeV. The measurement is performed inclusively for Z/gamma* rapidities up to 2.4, as well as in three rapidity bins. The channel results are combined, compared to perturbative and resummed QCD calculations and used to constrain the parton shower parameters of Monte Carlo generators.

339 citations

Journal ArticleDOI
Georges Aad1, Brad Abbott2, Jalal Abdallah3, S. Abdel Khalek4  +2870 moreInstitutions (169)
TL;DR: The performance of the ATLAS muon reconstruction during the LHC run withpp collisions at s=7–8 TeV in 2011–2012 is presented, focusing mainly on data collected in 2012.
Abstract: This paper presents the performance of the ATLAS muon reconstruction during the LHC run with pp collisions at root s = 7-8 TeV in 2011-2012, focusing mainly on data collected in 2012. Measurements ...

305 citations


Cited by
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Georges Aad1, E. Abat2, Jalal Abdallah3, Jalal Abdallah4  +3029 moreInstitutions (164)
23 Feb 2020
TL;DR: The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper, where a brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.
Abstract: The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.

3,111 citations

Journal Article
TL;DR: In this paper, the ATLAS experiment is described as installed in i ts experimental cavern at point 1 at CERN and a brief overview of the expec ted performance of the detector is given.
Abstract: This paper describes the ATLAS experiment as installed in i ts experimental cavern at point 1 at CERN. It also presents a brief overview of the expec ted performance of the detector.

2,798 citations

Journal ArticleDOI
John Allison1, K. Amako2, John Apostolakis3, Pedro Arce4, Makoto Asai5, Tsukasa Aso6, Enrico Bagli, Alexander Bagulya7, Sw. Banerjee8, G. Barrand9, B. R. Beck10, Alexey Bogdanov11, D. Brandt, Jeremy M. C. Brown12, Helmut Burkhardt3, Ph Canal8, D. Cano-Ott4, Stephane Chauvie, Kyung-Suk Cho13, G.A.P. Cirrone14, Gene Cooperman15, M. A. Cortés-Giraldo16, G. Cosmo3, Giacomo Cuttone14, G.O. Depaola17, Laurent Desorgher, X. Dong15, Andrea Dotti5, Victor Daniel Elvira8, Gunter Folger3, Ziad Francis18, A. Galoyan19, L. Garnier9, M. Gayer3, K. Genser8, Vladimir Grichine7, Vladimir Grichine3, Susanna Guatelli20, Susanna Guatelli21, Paul Gueye22, P. Gumplinger23, Alexander Howard24, Ivana Hřivnáčová9, S. Hwang13, Sebastien Incerti25, Sebastien Incerti26, A. Ivanchenko3, Vladimir Ivanchenko3, F.W. Jones23, S. Y. Jun8, Pekka Kaitaniemi27, Nicolas A. Karakatsanis28, Nicolas A. Karakatsanis29, M. Karamitrosi30, M.H. Kelsey5, Akinori Kimura31, Tatsumi Koi5, Hisaya Kurashige32, A. Lechner3, S. B. Lee33, Francesco Longo34, M. Maire, Davide Mancusi, A. Mantero, E. Mendoza4, B. Morgan35, K. Murakami2, T. Nikitina3, Luciano Pandola14, P. Paprocki3, J Perl5, Ivan Petrović36, Maria Grazia Pia, W. Pokorski3, J. M. Quesada16, M. Raine, Maria A.M. Reis37, Alberto Ribon3, A. Ristic Fira36, Francesco Romano14, Giorgio Ivan Russo14, Giovanni Santin38, Takashi Sasaki2, D. Sawkey39, J. I. Shin33, Igor Strakovsky40, A. Taborda37, Satoshi Tanaka41, B. Tome, Toshiyuki Toshito, H.N. Tran42, Pete Truscott, L. Urbán, V. V. Uzhinsky19, Jerome Verbeke10, M. Verderi43, B. Wendt44, H. Wenzel8, D. H. Wright5, Douglas Wright10, T. Yamashita, J. Yarba8, H. Yoshida45 
TL;DR: Geant4 as discussed by the authors is a software toolkit for the simulation of the passage of particles through matter, which is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection.
Abstract: Geant4 is a software toolkit for the simulation of the passage of particles through matter. It is used by a large number of experiments and projects in a variety of application domains, including high energy physics, astrophysics and space science, medical physics and radiation protection. Over the past several years, major changes have been made to the toolkit in order to accommodate the needs of these user communities, and to efficiently exploit the growth of computing power made available by advances in technology. The adaptation of Geant4 to multithreading, advances in physics, detector modeling and visualization, extensions to the toolkit, including biasing and reverse Monte Carlo, and tools for physics and release validation are discussed here.

2,260 citations

Journal ArticleDOI
TL;DR: In this article, the first set of parton distribution functions (PDFs) determined with a methodology validated by a closure test is presented, which is based on LO, NLO and NNLO QCD theory and also includes electroweak corrections.
Abstract: We present NNPDF3.0, the first set of parton distribution functions (PDFs) determined with a methodology validated by a closure test. NNPDF3.0 uses a global dataset including HERA-II deep-inelastic inclusive cross-sections, the combined HERA charm data, jet production from ATLAS and CMS, vector boson rapidity and transverse momentum distributions from ATLAS, CMS and LHCb, W+c data from CMS and top quark pair production total cross sections from ATLAS and CMS. Results are based on LO, NLO and NNLO QCD theory and also include electroweak corrections. To validate our methodology, we show that PDFs determined from pseudo-data generated from a known underlying law correctly reproduce the statistical distributions expected on the basis of the assumed experimental uncertainties. This closure test ensures that our methodological uncertainties are negligible in comparison to the generic theoretical and experimental uncertainties of PDF determination. This enables us to determine with confidence PDFs at different perturbative orders and using a variety of experimental datasets ranging from HERA-only up to a global set including the latest LHC results, all using precisely the same validated methodology. We explore some of the phenomenological implications of our results for the upcoming 13 TeV Run of the LHC, in particular for Higgs production cross-sections.

2,028 citations