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Tevatron Constraints on Models of the Higgs Boson with Exotic Spin and Parity Using Decays to Bottom-Antibottom Quark Pairs

  • Aaltonen, Timo Antero
  • Casal Laraña, Bruno
  • Cuevas Maestro, Francisco Javier
  • Gómez Gramuglio, Gervasio
  • Palencia Cortezón, José Enrique
  • Ruiz Jimeno, Alberto
  • Scodellaro, Luca
  • Vilar Cortabitarte, Rocío
  • Vizán García, Jesús Manuel
Combined constraints from the CDF and D0 Collaborations on models of the Higgs boson with exotic spin J and parity P are presented and compared with results obtained assuming the standard model value JP=0+. Both collaborations analyzed approximately 10??fb-1 of proton-antiproton collisions with a center-of-mass energy of 1.96 TeV collected at the Fermilab Tevatron. Two models predicting exotic Higgs bosons with JP=0- and JP=2+ are tested. The kinematic properties of exotic Higgs boson production in association with a vector boson differ from those predicted for the standard model Higgs boson. Upper limits at the 95% credibility level on the production rates of the exotic Higgs bosons, expressed as fractions of the standard model Higgs boson production rate, are set at 0.36 for both the JP=0- hypothesis and the JP=2+ hypothesis. If the production rate times the branching ratio to a bottom-antibottom pair is the same as that predicted for the standard model Higgs boson, then the exotic bosons are excluded with significances of 5.0 standard deviations and 4.9 standard deviations for the JP=0- and JP=2+ hypotheses, respectively., We thank the Fermilab staff and technical staffs of the participating institutions for their vital contributions. We acknowledge support from the Department of Energy and the National Science Foundation (United States of America), the Australian Research Council (Australia),the National Council for the Development of Science and Technology and the Carlos Chagas Filho Foundation for the Support of Research in the State of Rio de Janeiro(Brazil), the Natural Sciences and Engineering Research Council (Canada), the China Academy of Sciences, the National Natural Science Foundation of China, and the National Science Council of the Republic of China (China),the Administrative Department of Science, Technology and Innovation (Colombia), the Ministry of Education, Youthand Sports (Czech Republic), the Academy of Finland(Finland), the Alternative Energies and Atomic Energy Commission and the National Center for Scientific Research/National Institute of Nuclear and Particle Physics (France), the Bundesministerium für Bildungund Forschung (Federal Ministry of Education and Research) and the Deutsche Forschungsgemeinschaft (German Research Foundation) (Germany), the Department of Atomic Energy and Department of Science and Technology (India), the Science Foundation Ireland (Ireland), the National Institute for Nuclear Physics(Italy), the Ministry of Education, Culture, Sports, Science and Technology (Japan), the Korean World Class University Program and the National Research Foundation of Korea (Korea), the National Council of Science and Technology (Mexico), the Foundation for Fundamental Research on Matter (The Netherlands), theMinistry of Education and Science of the Russian Federation, the National Research Center “KurchatovInstitute” of the Russian Federation, and the Russian Foundation for Basic Research (Russia), the Slovak R&D Agency (Slovakia), the Ministry of Science and Innovation, and the Consolider-Ingenio 2010 Program(Spain), the Swedish Research Council (Sweden), the Swiss National Science Foundation (Switzerland), the Ministry of Education and Science of Ukraine (Ukraine),the Science and Technology Facilities Council and The Royal Society (United Kingdom), the A.P. Sloan Foundation (USA), and the European Commission Marie Curie Fellowship, Contract No. 302103.
Proyecto:


First measurement of the forward-backward asymmetry in bottom-quark pair production at high mass

  • Aaltonen, Timo Antero
  • Casal Laraña, Bruno
  • Cuevas Maestro, Francisco Javier
  • Gómez Gramuglio, Gervasio
  • Palencia Cortezón, José Enrique
  • Ruiz Jimeno, Alberto
  • Scodellaro, Luca
  • Vilar Cortabitarte, Rocío
  • Vizán García, Jesús Manuel
We measure the particle-level forward-backward production asymmetry in b¯b pairs with masses (mb¯b) larger than 150  GeV/c2, using events with hadronic jets and employing jet charge to distinguish b from ¯b. The measurement uses 9.5  fb−1 of p¯p collisions at a center-of-mass energy of 1.96 TeV recorded by the CDF II detector. The asymmetry as a function of mb¯b is consistent with zero, as well as with the predictions of the standard model. The measurement disfavors a simple model including an axigluon with a mass of 200  GeV/c2, whereas a model containing a heavier 345  GeV/c2 axigluon is not excluded., We thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionaledi Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada; The National Science Council of the Republic of China; the Swiss National Science Foundation; the A. P. Sloan Foundation; the Bundesministerium für Bildung und Forschung, Germany; the Korean World Class University Program, the National Research Foundation of Korea; theScience and Technology Facilities Council and the Royal Society, United Kingdom; the Russian Foundation for Basic Research; the Ministerio de Ciencia e Innovación, and Programa Consolider-Ingenio 2010, Spain; the Slovak R&D Agency; the Academy of Finland; the Australian Research Council; and the EU community Marie Curie Fellowship Contract No. 302103.
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Measurement of central exclusive π+π− production in p¯p collisions at √s=0.9 and 1.96 TeV at CDF

  • Aaltonen, Timo Antero
  • Casal Laraña, Bruno
  • Cuevas Maestro, Francisco Javier
  • Gómez Gramuglio, Gervasio
  • Palencia Cortezón, José Enrique
  • Ruiz Jimeno, Alberto
  • Scodellaro, Luca
  • Vilar Cortabitarte, Rocío
  • Vizán García, Jesús Manuel
We measure exclusive π+π− production in proton-antiproton collisions at center-of-mass energies √s=0.9 and 1.96 TeV in the Collider Detector at Fermilab. We select events with two oppositely charged particles, assumed to be pions, with pseudorapidity |η|<1.3 and with no other particles detected in |η|<5.9. We require the π+π− system to have rapidity |y|<1.0. The production mechanism of these events is expected to be dominated by double pomeron exchange, which constrains the quantum numbers of the central state. The data are potentially valuable for isoscalar meson spectroscopy and for understanding the pomeron in a region of transition between nonperturbative and perturbative quantum chromodynamics. The data extend up to dipion mass M(π+π−)=5000  MeV/c2 and show resonance structures attributed to f0 and f2(1270) mesons. From the π+π− and K+K− spectra, we place upper limits on exclusive χc0(3415) production., […] the Ministerio de Ciencia e Innovación, and Programa Consolider-Ingenio 2010, Spain[…]
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Measurement of the production and differential cross sections of W+W− bosons in association with jets in p¯p collisions at √s=1.96  TeV

  • Aaltonen, Timo Antero
  • Casal Laraña, Bruno
  • Cuevas Maestro, Francisco Javier
  • Gómez Gramuglio, Gervasio
  • Palencia Cortezón, José Enrique
  • Ruiz Jimeno, Alberto
  • Scodellaro, Luca
  • Vilar Cortabitarte, Rocío
  • Vizán García, Jesús Manuel
We present a measurement of the W-boson-pair production cross section in p¯p collisions at 1.96 TeV center-of-mass energy and the first measurement of the differential cross section as a function of jet multiplicity and leading-jet energy. The W+W− cross section is measured in the final state comprising two charged leptons and neutrinos, where either charged lepton can be an electron or a muon. Using data collected by the CDF experiment corresponding to 9.7  fb−1 of integrated luminosity, a total of 3027 collision events consistent with W+W− production are observed with an estimated background contribution of 1790±190 events. The measured total cross section is σ(p¯p→W+W−)=14.0±0.6(stat)+1.2−1.0(syst)±0.8(lumi)  pb, consistent with the standard model prediction.
Proyecto:


Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix Element Vtb

  • Aaltonen, Timo Antero
  • Casal Laraña, Bruno
  • Cuevas Maestro, Francisco Javier
  • Gómez Gramuglio, Gervasio
  • Palencia Cortezón, José Enrique
  • Ruiz Jimeno, Alberto
  • Scodellaro, Luca
  • Vilar Cortabitarte, Rocío
  • Vizán García, Jesús Manuel
We present the final combination of CDF and D0 measurements of cross sections for single-top-quark production in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7??fb-1 per experiment. The t-channel cross section is measured to be st=2.25+0.29-0.31??pb. We also present the combinations of the two-dimensional measurements of the s- vs t-channel cross section. In addition, we give the combination of the s+t channel cross section measurement resulting in ss+t=3.30+0.52-0.40??pb, without assuming the standard model value for the ratio ss/st. The resulting value of the magnitude of the top-to-bottom quark coupling is |Vtb|=1.02+0.06-0.05, corresponding to |Vtb|>0.92 at the 95% C.L.
Proyecto:


Study of top quark production and decays involving a tau lepton at CDF and limits on a charged Higgs boson contribution

  • Aaltonen, Timo Antero
  • Casal Laraña, Bruno
  • Cuevas Maestro, Francisco Javier
  • Gómez Gramuglio, Gervasio
  • Palencia Cortezón, José Enrique
  • Ruiz Jimeno, Alberto
  • Scodellaro, Luca
  • Vilar Cortabitarte, Rocío
  • Vizán García, Jesús Manuel
We present an analysis of top-antitop quark production and decay into a tau lepton, tau neutrino, and bottom quark using data from 9??fb-1 of integrated luminosity at the Collider Detector at Fermilab. Dilepton events, where one lepton is an energetic electron or muon and the other a hadronically decaying tau lepton, originating from proton-antiproton collisions at vs=1.96??TeV, are used. A top-antitop quark production cross section of 8.1±2.1??pb is measured, assuming standard-model top quark decays. By separately identifying for the first time the single-tau and the ditau components, we measure the branching fraction of the top quark into the tau lepton, tau neutrino, and bottom quark to be (9.6±2.8)%. The branching fraction of top quark decays into a charged Higgs boson and a bottom quark, which would imply violation of lepton universality, is limited to be less than 5.9% at a 95% confidence level [for B(H-?t¯?)=1].
Proyecto:


Studies of high-transverse momentum jet substructure and top quarks produced in 1.96 TeV proton-antiproton collisions

  • Aaltonen, Timo Antero
  • Casal Laraña, Bruno
  • Cuevas Maestro, Francisco Javier
  • Gómez Gramuglio, Gervasio
  • Palencia Cortezón, José Enrique
  • Ruiz Jimeno, Alberto
  • Scodellaro, Luca
  • Vilar Cortabitarte, Rocío
  • Vizán García, Jesús Manuel
Results of a study of the substructure of the highest transverse momentum (pT) jets observed by the CDF Collaboration are presented. Events containing at least one jet with pT>400??GeV/c in a sample corresponding to an integrated luminosity of 5.95??fb-1, collected in 1.96 TeV proton-antiproton collisions at the Fermilab Tevatron collider, are selected. A study of the jet mass, angularity, and planar-flow distributions is presented, and the measurements are compared with predictions of perturbative quantum chromodynamics. A search for boosted top-quark production is also described, leading to a 95% confidence level upper limit of 38 fb on the production cross section of top quarks with pT>400??GeV/c., ACKNOWLEDGMENTS. The Ministerio de Ciencia e Innovación,and Programa Consolider-Ingenio 2010, Spain.
Proyecto:


Measurement of the Inclusive Leptonic Asymmetry in Top-Quark Pairs that Decay to Two Charged Leptons at CDF

  • Aaltonen, Timo Antero
  • Casal Laraña, Bruno
  • Cuevas Maestro, Francisco Javier
  • Gómez Gramuglio, Gervasio
  • Palencia Cortezón, José Enrique
  • Ruiz Jimeno, Alberto
  • Scodellaro, Luca
  • Vilar Cortabitarte, Rocío
  • Vizán García, Jesús Manuel
We measure the inclusive forward–backward asymmetry of the charged-lepton pseudorapidities from top-quark pairs produced in proton–antiproton collisions and decaying to final states that contain two charged leptons (electrons or muons). The data are collected with the Collider Detector at Fermilab and correspond to an integrated luminosity of 9.1??fb-1. We measure the leptonic forward–backward asymmetry, AlFB, to be 0.072±0.060 and the leptonic pair forward–backward asymmetry, AllFB, to be 0.076±0.082. The measured values can be compared with the standard model predictions of AlFB=0.038±0.003 and AllFB=0.048±0.004, respectively. Additionally, we combine the AlFB result with a previous determination from a final state with a single lepton and hadronic jets and obtain AlFB=0.090+0.028-0.026., We thank the Fermilab staff and the technical staffs of theparticipating institutions for their vital contributions. Thiswork was supported by the U.S. Department of Energy andNational Science Foundation; the Italian Istituto Nazionaledi Fisica Nucleare; the Ministry of Education, Culture,Sports, Science and Technology of Japan; the NaturalSciences and Engineering Research Council of Canada;the National Science Council of the Republic of China; theSwiss National Science Foundation; the A. P. SloanFoundation; the Bundesministerium für Bildung undForschung, Germany; the Korean World Class UniversityProgram, the National Research Foundation of Korea; theScience and Technology Facilities Council and the RoyalSociety, United Kingdom; the Russian Foundation forBasic Research; the Ministerio de Ciencia e Innovación,and Programa Consolider-Ingenio 2010, Spain; the SlovakR&D Agency; the Academy of Finland; the AustralianResearch Council (ARC); and the EU community MarieCurie Fellowship Contract No. 302103
Proyecto:


Indirect measurement of sin2?W (or MW) using µ+µ- pairs from ?*/Z bosons produced in p¯p collisions at a center-of-momentum energy of 1.96 TeV

  • Aaltonen, Timo Antero
  • Casal Laraña, Bruno
  • Cuevas Maestro, Francisco Javier
  • Gómez Gramuglio, Gervasio
  • Palencia Cortezón, José Enrique
  • Ruiz Jimeno, Alberto
  • Scodellaro, Luca
  • Vilar Cortabitarte, Rocío
  • Vizán García, Jesús Manuel
Drell-Yan lepton pairs are produced in the process p¯p?µ+µ-+X through an intermediate ?*/Zboson. The forward-backward asymmetry in the polar-angle distribution of the µ- as a function of the invariant mass of the µ+µ- pair is used to obtain the effective leptonic determination sin2?lepteff of the electroweak-mixing parameter sin2?W, from which the value of sin2?W is derived assuming the standard model. The measurement sample, recorded by the Collider Detector at Fermilab (CDF), corresponds to 9.2??fb-1 of integrated luminosity from p¯p collisions at a center-of-momentum energy of 1.96 TeV, and is the full CDF Run II data set. The value of sin2?lepteff is found to be 0.2315±0.0010, where statistical and systematic uncertainties are combined in quadrature. When interpreted within the context of the standard model using the on-shell renormalization scheme, where sin2?W=1-M2W/M2Z, the measurement yields sin2?W=0.2233±0.0009, or equivalently a W-boson mass of 80.365±0.047??GeV/c2. The value of the W-boson mass is in agreement with previous determinations in electron-positron collisions and at the Tevatron collider., ACKNOWLEDGMENTS. We thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions. Thiswork was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionaledi Fisica Nucleare; the Ministry of Education, Culture,Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada;the National Science Council of the Republic of China; theSwiss National Science Foundation; the A. P. Sloan Foundation; the Bundesministerium für Bildung und Forschung, Germany; the Korean World Class University Program, the National Research Foundation of Korea; the Science and Technology Facilities Council and the Royal Society, United Kingdom; the Russian Foundation forBasic Research; the Ministerio de Ciencia e Innovación,and Programa Consolider-Ingenio 2010, Spain; the SlovakR&D Agency; the Academy of Finland; the Australian Research Council (ARC); and the EU community Marie Curie Fellowship Contract No. 302103.
Proyecto:


Study of the energy dependence of the underlying event in proton-antiproton collision

  • Aaltonen, Timo Antero
  • Casal Laraña, Bruno
  • Cuevas Maestro, Francisco Javier
  • Gómez Gramuglio, Gervasio
  • Palencia Cortezón, José Enrique
  • Ruiz Jimeno, Alberto
  • Scodellaro, Luca
  • Vilar Cortabitarte, Rocío
  • Vizán García, Jesús Manuel
We study charged particle production (pT>0.5??GeV/c, |?|<0.8) in proton-antiproton collisions at total center-of-mass energies vs=300??GeV, 900 GeV, and 1.96 TeV. We use the direction of the charged particle with the largest transverse momentum in each event to define three regions of ?-? space: “toward”, “away”, and “transverse.” The average number and the average scalar pT sum of charged particles in the transverse region are sensitive to the modeling of the “underlying event.” The transverse region is divided into a MAX and MIN transverse region, which helps separate the “hard component” (initial and final-state radiation) from the “beam-beam remnant” and multiple parton interaction components of the scattering. The center-of-mass energy dependence of the various components of the event is studied in detail. The data presented here can be used to constrain and improve QCD Monte Carlo models, resulting in more precise predictions at the LHC energies of 13 and 14 TeV., We thank the Fermilab staff and the technical staffs of theparticipating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionaledi Fisica Nucleare; the Ministry of Education, Culture,Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada;the National Science Council of the Republic of China; the Swiss National Science Foundation; the A. P. Sloan Foundation; the Bundesministerium für Bildung und Forschung, Germany; the Korean World Class University Program, the National Research Foundation of Korea; the Science and Technology Facilities Council and the Royal Society, United Kingdom; the Russian Foundation forBasic Research; the Ministerio de Ciencia e Innovación,and Programa Consolider-Ingenio 2010, Spain; the SlovakR&D Agency; the Academy of Finland; the Australian Research Council (ARC); and the EU community Marie Curie Fellowship Contract No. 302103.[1] R. Field,Annu. Rev. Nucl. Part. Sci.62, 453 (2012).[2] T. Aaltonenet al.(CDF Collaboration),Phys. Rev. D65,092002 (2002).[3] T. Aaltonenet al.(CDF Collaboration),Phys. Rev. D82,034001 (2010).[4] Using transMAX and transMIN was first suggested by Bryan Webber and implemented in a paper by J. Pumplin,Phys. Rev. D57, 5787 (1998).[5] T. Sjöstrand,Phys. Lett.157B, 321 (1985); M. Bengtsson,T. Sjöstrand, and M. van Zijl,Z. Phys. C32, 67 (1986);T.Sjöstrand and M. van Zijl,Phys. Rev. D36, 2019 (1987);T.Sjöstrand, P. Eden, C. Friberg, L. Lonnblad, G. Miu, S.Mrenna, and E. Norrbin,Comput. Phys. Commun.135, 238(2001).[6] R. Field,arXiv:hep-ph/0610012;FERMILAB-Conf-06-359, 2006.T. AALTONENet al.PHYSICAL REVIEW D92,092009 (2015)092009-20
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