Browsing by Author "Díaz, Marco A."

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    A precise measurement of the Z-boson double-differential transverse momentum and rapidity distributions in the full phase space of the decay leptons with the ATLAS experiment at √s = 8 TeV
    (2024) Abusleme Hoffman, Ángel Christian; Díaz, Marco A.; Garay Walls, Francisca; ATLAS Collaboration
    This paper presents for the first time a precise measurement of the production properties of the Z boson in the full phase space of the decay leptons. This is in contrast to the many previous precise unfolded measurements performed in the fiducial phase space of the decay leptons. The measurement is obtained from proton–proton collision data collected by the ATLAS experiment in 2012 at √s = 8 TeV at the LHC and corresponding to an integrated luminosity of 20.2 fb−1. The results, based on a total of 15.3 million Zboson decays to electron and muon pairs, extend and improve a previous measurement of the full set of angular coefficients describing Z-boson decay. The double-differential crosssection distributions in Z-boson transverse momentum pT and rapidity y are measured in the pole region, defined as 80 < m < 100 GeV, over the range |y| < 3.6. The totaluncertainty of the normalised cross-section measurements in the peak region of the pT distribution is dominated by statistical uncertainties over the full range and increases as a function of rapidity from 0.5–1.0% for |y| < 2.0 to 2 − 7% at higher rapidities. The results for the rapidity-dependenttransverse momentum distributions are compared to stateof-the-art QCD predictions, which combine in the best cases approximate N4LL resummation with N3LO fixed-order perturbative calculations. The differential rapidity distributions integrated over pT are even more precise, with accuracies from 0.2–0.3% for |y| < 2.0 to 0.4–0.9% at higher rapidities, and are compared to fixed-order QCD predictions using the most recent parton distribution functions. The agreementbetween data and predictions is quite good in most cases.
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    A search for R-parity-violating supersymmetry in final states containing many jets in pp collisions at √s=13TeV with the ATLAS detector
    (2024) Díaz, Marco A.; Garay Walls, Francisca M.; Urrejola, P.
    A search for R-parity-violating supersymmetry in fnal states with high jet multiplicity is presented. The search uses 140 fb−1 of proton-proton collision data at √ s = 13 TeV collected by the ATLAS experiment during Run 2 of the Large Hadron Collider. The results are interpreted in the context of R-parity-violating supersymmetry models that feature prompt gluino-pair production decaying directly to three jets each or decaying to two jets and a neutralino which subsequently decays promptly to three jets. No signifcant excess over the Standard Model expectation is observed and exclusion limits at the 95% confdence level are extracted. Gluinos with masses up to 1800 GeV are excluded when decaying directly to three jets. In the cascade scenario, gluinos with masses up to 2340 GeV are excluded for a neutralino with mass up to 1250 GeV.
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    A search for t(t)over-bar resonances using lepton-plus-jets events in proton-proton collisions at root s=8 TeV with the ATLAS detector
    (2015) Aad, G.; Abbott, B.; Abdallah, J.; Aben, R.; Abolins, M.; AbouZeid O. S.; Carquín López, Edson Leonardo; Díaz, Marco A.; Ochoa-Ricoux, Juan Pedro; Vogel, M.
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    A search for top-squark pair production, in final states containing a top quark, a charm quark and missing transverse momentum, using the 139 fb−1 of pp collision data collected by the ATLAS detector
    (2024) Aad, G.; Abbott, B.; Abeling, K.; Abicht, N. J.; Abidi, S. H.; Aboulhorma, A.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B. S.; Bourdarios, A.; Adamczyk, L.; Addepalli, S. V.; Addison, M. J.; Adelman, J.; Adiguzel, A.; Adye, T.; Díaz, Marco A.; Garay Walls, Francisca; Urrejola Pereira, Pedro Salvador; ATLAS Collaboration
    Abstract: This paper presents a search for top-squark pair production in fnal states with a top quark, a charm quark and missing transverse momentum. The data were collected with the ATLAS detector during LHC Run 2 and correspond to an integrated luminosity of 139 fb−1 of proton-proton collisions at a centre-of-mass energy of √s = 13 TeV. The analysis is motivated by an extended Minimal Supersymmetric Standard Model featuring a non-minimal favour violation in the second- and third-generation squark sector. The top squark in this model has two possible decay modes, either t˜1 → cχ˜01 or t˜1 → tχ˜01, where the χ˜01 is undetected. The analysis is optimised assuming that both of the decay modes are equally probable, leading to the most likely fnal state of tc + Emiss T. Good agreement is found between the Standard Model expectation and the data in the search regions. Exclusion limits at 95% CL are obtained in the m(t˜1) vs. m(χ˜01) plane and, in addition, limits on the branching ratio of the t˜1 → tχ˜0 1 decay as a function of m(t˜1) are also produced. Top-squark masses of up to 800 GeV are excluded for scenarios with light neutralinos, and top-squark masses up to 600 GeV are excluded in scenarios where the neutralino and the top squark are almost mass degenerate.
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    A strategy for a general search for new phenomena using data-derived signal regions and its application within the ATLAS experiment
    (2019) Aaboud, M.; Aad, G.; Abbott, B.; Abdinov, O.; Blunier, Sylvain; Díaz, Marco A.; Lee, Graham Richard; Ochoa-Ricoux, Juan Pedro; Olivares Pino, Sebastián Andrés; Rivera Vergara, Javiera Constanza
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    A study of the material in the ATLAS inner detector using secondary hadronic interactions
    (2012) Aad, G.; Díaz, Marco A.; Quiñonez Granados, Fernando Andrés; Panes Saavedra, Boris
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    A. search for an excited muon decaying to a muon and two jets in pp collisions at root s=8 TeV. with the ATLAS. detector
    (2016) Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Ochoa-Ricoux, Juan Pedro; Díaz, Marco A.; Carquín López, Edson Leonardo
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    A. search for prompt lepton-jets in pp collisions at root s=8 TeV. with the ATLAS. detector
    (2016) Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Ochoa-Ricoux, Juan Pedro; Díaz, Marco A.; Carquín López, Edson Leonardo
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    A. search for top squarks with R-parity-violating decays to all-hadronic final states with the ATLAS. detector in root s=8 TeV. proton-proton collisions
    (2016) Aad. G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Ochoa-Ricoux, Juan Pedro; Díaz, Marco A.; Carquín López, Edson Leonardo
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    Alignment of the ATLAS Inner Detector in Run 2
    (2020) Aad, G.; Abbott, B.; Abbott, D. C.; Abud, A. A.; Abeling, K.; Abhayasinghe, D. K.; Díaz, Marco A.; Garay Walls, Francisca; Ochoa-Ricoux, Juan Pedro; Olivares Pino, Sebastian Andrés; Abidi S.H.; AbouZeid O.S.; Abraham N.L.; Abramowicz H.; Abreu H.; Abulaiti Y.; Acharya B.S.; Achkar B.; Adam L.; Bourdarios C.A.; Adamczyk L.; Adamek L.; Adelman J.; Adersberger M.; Adiguzel A.; Adorni S.; Adye T.; Affolder A.A.; Afik Y.; Agapopoulou C.; Agaras M.N.; Aggarwal A.; Agheorghiesei C.; Aguilar-Saavedra J.A.; Ahmad A.; Ahmadov F.; Ahmed W.S.; Ai X.; Aielli G.; Akatsuka S.; Akbiyik M.; Åkesson T.P.A.; Akilli E.; Akimov A.V.; Khoury K.A.; Alberghi G.L.; Albert J.; Verzini M.J.A.; Alderweireldt S.; Aleksa M.; Aleksandrov I.N.; Aad, G.; Abbott, B.; Abbott, D. C.; Abud, A. A.; Abeling, K.; Abhayasinghe, D. K.; Díaz, Marco A.; Garay Walls, Francisca; Ochoa-Ricoux, Juan Pedro; Olivares Pino, Sebastian Andrés; Abidi S.H.; AbouZeid O.S.; Abraham N.L.; Abramowicz H.; Abreu H.; Abulaiti Y.; Acharya B.S.; Achkar B.; Adam L.; Bourdarios C.A.; Adamczyk L.; Adamek L.; Adelman J.; Adersberger M.; Adiguzel A.; Adorni S.; Adye T.; Affolder A.A.; Afik Y.; Agapopoulou C.; Agaras M.N.; Aggarwal A.; Agheorghiesei C.; Aguilar-Saavedra J.A.; Ahmad A.; Ahmadov F.; Ahmed W.S.; Ai X.; Aielli G.; Akatsuka S.; Akbiyik M.; Åkesson T.P.A.; Akilli E.; Akimov A.V.; Khoury K.A.; Alberghi G.L.; Albert J.; Verzini M.J.A.; Alderweireldt S.; Aleksa M.; Aleksandrov I.N.
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    An extensive study of models beyond the standard model
    (2020) Maturana Ávila, Ivania; Díaz, Marco A.; Pontificia Universidad Católica de Chile. Instituto de Física
    El presente trabajo se centró en el estudio fenomenológico de tres modelos que son extensiones del actual Modelo Estandar: El Inert Higgs Doublet Model, el Scotogenic Model and el Singlet + Triplet Scotogenic Model. La motivación de estudiar estos modelos se basa en que pueden explicar algunas de las preguntas existentes en física hoy en día; todos ellos presentan una particula que será candidato a materia oscura y los últimos dos proponen un mecanismo para dar masa a al menos dos neutrinos. En todos los modelos hemos considerado la generación de la abudancia de materia oscura en un escenario de freeze-out y la partícula candidata a materia oscura será un escalar massivo debilmente interactuante (WIMP definido por su nombre en inglés). El primer trabajo está relacionado con estudiar las principales diferencias entre el Inert Higgs Doiblet Model and el Scotogenic Model. Hemos realizado un estudio profundo de la materia oscura en ambos, investigando puntos que sobrevivan a las cotas mas fuertes en física y en los actuales experimentos y también considerando que estos resultados pueden explicar la densidad de materia oscura en el Universo en su totalidad. Estudiando una señal específica en el Compact Linear Collider (CLIC), investigamos los parámetros que contribuirán a obtener diferentes valores para la sección eficaz en ambos modelos. En el segundo trabajo, hemos reexaminado el Singlet + Triplet Scotogenic Model el cual generaliza la idea introducida en el Scotogenic model simple, haciendo su fenomenología viable y mucho mas rica. Relalizamos un estudio fenomenológico detallado de la materia oscura escalar, actualizando las cotas actuales de los experimentos. Investigamos la detección directa de dark matter y la detección indirecta vía rayos gamma. Además, realizamos un estudio en colisionadores el cual tendrá relevantes implicaciones para las futuras búsquedas a alta luminosidad del Large Hadron Collider (LHC definido por su nombre en inglés).
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    Analysis of events with b-jets and a pair of leptons of the same charge in pp collisions at √s=8 TeV with the ATLAS detector
    (2015) Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Aben, R.; Abolins, M.; Abou Zeid, O. S.; Carquín López, Edson Leonardo; Díaz, Marco A.; Vogel, M.
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    Analysis of the Wtb vertex from the measurement of triple-differential angular decay rates of single top quarks produced in the t-channel at root s=8 TeV with the ATLAS detector
    (2017) Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Abidi, S.; Díaz, Marco A.; Lee, Graham Richard; Ochoa-Ricoux, Juan Pedro; Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Abidi, S.; Díaz, Marco A.; Lee, Graham Richard; Ochoa-Ricoux, Juan Pedro; Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Abidi, S.; Díaz, Marco A.; Lee, Graham Richard; Ochoa-Ricoux, Juan Pedro; Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Abidi, S.; Díaz, Marco A.; Lee, Graham Richard; Ochoa-Ricoux, Juan Pedro; Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Abidi, S.; Díaz, Marco A.; Lee, Graham Richard; Ochoa-Ricoux, Juan Pedro; Aaboud, M.; Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Abeloos, B.; Abidi, S.; Díaz, Marco A.; Lee, Graham Richard; Ochoa-Ricoux, Juan Pedro
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    Angular analysis of B0 d → K∗µ+µ− decays in pp collisions at √s = 8 TeV with the ATLAS detector
    (2018) Blunier, Sylvain; Díaz, Marco A.; Ochoa-Ricoux, Juan Pedro
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    Anomaly Mediated Supersymmetry Breaking Without R-Parity
    (2002) De Campos F; Díaz, Marco A.
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    Answering medical questions at the point of care : a cross-sectional study comparing rapid decisions based on PubMed and Epistemonikos searches with evidence-based recommendations developed with the GRADE approach
    (2017) Izcovich, A.; Criniti, J.; Popoff, F.; Ragusa, M.; Gigler, C.; Malla, C.; Clavijo, M.; Manzotti, M.; Díaz, Marco A.; Neumann Burotto, Gonzalo Ignacio; Catalano, H.; Guyatt, G.
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    ATLAS Collaboration
    (2014) Abajyan, T.; Abbott, B.; Díaz, Marco A.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Agatonovic Jovin, T.; Aguilar Saavedra, J. A.
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    ATLAS measurements of the properties of jets for boosted particle searches
    (2012) Aad, G.; Díaz, Marco A.; Olivares Pino, Sebastián Andrés.; Quiñonez Granados, Fernando Andrés
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    ATLAS Run 1 searches for direct pair production of third-generation squarks at the Large Hadron Collider
    (2015) Aad, G.; Abbott, B.; Abdallah, J.; Abdinov, O.; Aben, R.; Abolins, M.; Carquín López, Edson Leonardo; Díaz, Marco A.; Ochoa-Ricoux, Juan Pedro; Vogel, M.; Abouzeid, O.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B.; Adamczyk, L.; Adams, D.; Adelman, J.