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Abstract:

A search for the associated production of the Higgs boson with a top quark pair is performed in multilepton final states using 20.3 fb −1 of proton–proton collision data recorded by the ATLAS experiment at s=8 TeV at the Large Hadron Collider. Five final states, targeting the decays H→WW ⁎ , ττ, and ZZ ⁎ , are examined for the presence of the Standard Model (SM) Higgs boson: two same-charge light leptons (e or μ) without a hadronically decaying τ lepton; three light leptons; two same-charge light leptons with a hadronically decaying τ lepton; four light leptons; and one light lepton and two hadronically decaying τ leptons. No significant excess of events is observed above the background expectation. The best fit for the tt¯H production cross section, assuming a Higgs boson mass of 125 GeV, is 2.1 −1.2 +1.4 times the SM expectation, and the observed (expected) upper limit at the 95% confidence level is 4.7 (2.4) times the SM rate. The p-value for compatibility with the background-only hypothesis is 1.8σ; the expectation in the presence of a Standard Model signal is 0.9σ. © 2015 CERN for the benefit of the ATLAS Collaboration.

Registro:

Documento: Artículo
Título:Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector
Autor:Aad, G. et al.
Este artículo contiene 2829 autores, consultelos en el artículo en formato pdf.
Filiación: Este artículo contiene 2829 autores con sus filiaciones, consultelas en el artículo en formato pdf.
Año:2015
Volumen:749
Página de inicio:519
Página de fin:541
DOI: http://dx.doi.org/10.1016/j.physletb.2015.07.079
Título revista:Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
Título revista abreviado:Phys Lett Sect B Nucl Elem Part High-Energy Phys
ISSN:03702693
CODEN:PYLBA
Registro:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03702693_v749_n_p519_Aad

Referencias:

  • Glashow, S.L., Partial symmetries of weak interactions (1961) Nucl. Phys., 22, p. 579
  • Weinberg, S., A model of leptons (1967) Phys. Rev. Lett., 19, p. 1264
  • Salam, A., Weak and electromagnetic interactions (1968) Elementary Particle Theory: Relativistic Groups and Analyticity. Proceedings of the Eighth Nobel Symposium, p. 367. , N. Svartholm Almqvist & Wiksell Stockholm
  • Englert, F., Brout, R., Broken symmetry and the mass of gauge vector mesons (1964) Phys. Rev. Lett., 13, p. 321
  • Higgs, P.W., Broken symmetries, massless particles and gauge fields (1964) Phys. Rev. Lett., 12, p. 132
  • Higgs, P.W., Broken symmetries and the masses of gauge bosons (1964) Phys. Rev. Lett., 13, p. 508
  • Guralnik, G., Hagen, C.R., Kibble, T.W.B., Global conservation laws and massless particles (1964) Phys. Rev. Lett., 13, p. 585
  • Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC (2012) Phys. Lett. B, 716, p. 1
  • Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC (2012) Phys. Lett. B, 716, p. 30
  • Measurement of Higgs boson production in the diphoton decay channel in pp collisions at center-of-mass energies of 7 and 8 TeV with the ATLAS detector (2014) Phys. Rev. D, 90
  • Observation of the diphoton decay of the Higgs boson and measurement of its properties (2014) Eur. Phys. J. C, 74, p. 3076
  • Measurements of Higgs boson production and couplings in the four-lepton channel in pp collisions at center-of-mass energies of 7 and 8 TeV with the ATLAS detector (2015) Phys. Rev. D, 91
  • Measurement of the properties of a Higgs boson in the four-lepton final state (2014) Phys. Rev. D, 89
  • Observation and measurement of Higgs boson decays to WW ⁎ with the ATLAS detector (2015) Phys. Rev. D, 92
  • Measurement of Higgs boson production and properties in the WW decay channel with leptonic final states (2014) J. High Energy Phys., 1401
  • Evidence for the Higgs-boson Yukawa coupling to tau leptons with the ATLAS detector (2015) J. High Energy Phys., 1504
  • Evidence for the 125 GeV Higgs boson decaying to a pair of τ leptons (2014) J. High Energy Phys., 1405
  • Search for the associated production of the Higgs boson with a top-quark pair , 1409. , Erratum:; Search for the standard model Higgs boson produced in association with top quarks and decaying into bb¯ in pp collisions at s=8 TeV with the ATLAS detector (2015) Eur. Phys. J. C, 75, p. 349
  • Search for H→γγ produced in association with top quarks and constraints on the Yukawa coupling between the top quark and the Higgs boson using data taken at 7 TeV and 8 TeV with the ATLAS detector (2015) Phys. Lett. B, 740, p. 222
  • ATLAS experiment at the CERN Large Hadron Collider (2008) J. Instrum., 3
  • Dawson, S., Jackson, C., Orr, L., Reina, L., Wackeroth, D., Associated Higgs production with top quarks at the Large Hadron Collider: NLO QCD corrections (2003) Phys. Rev. D, 68
  • Reina, L., Dawson, S., Next-to-leading order results for tt¯h production at the Tevatron (2001) Phys. Rev. Lett., 87
  • Beenakker, W., NLO QCD corrections to tt¯H production in hadron collisions (2003) Nucl. Phys. B, 653, p. 151
  • Beenakker, W., Higgs radiation off top quarks at the Tevatron and the LHC (2001) Phys. Rev. Lett., 87
  • Dittmaier, S., Handbook of LHC Higgs cross sections: 1. Inclusive observables ; Heinemeyer, S., Handbook of LHC Higgs cross sections: 3. Higgs properties ; Combined measurement of the Higgs boson mass in pp collisions at s=7 and 8 TeV with the ATLAS and CMS experiments (2015) Phys. Rev. Lett., 114
  • Alwall, J., The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations (2014) J. High Energy Phys., 1407
  • Campbell, J.M., Ellis, R.K., tt¯W ± production and decay at NLO (2012) J. High Energy Phys., 1207
  • Garzelli, M., Kardos, A., Papadopoulos, C., Trocsanyi, Z., tt¯W ± and tt¯Z hadroproduction at NLO accuracy in QCD with parton shower and hadronization effects (2012) J. High Energy Phys., 1211
  • Campbell, J.M., Ellis, R.K., Röntsch, R., Single top production in association with a Z boson at the LHC (2013) Phys. Rev. D, 87
  • Alwall, J., Herquet, M., Maltoni, F., Mattelaer, O., Stelzer, T., MadGraph 5: going beyond (2011) J. High Energy Phys., 1106
  • Campbell, J.M., Ellis, R.K., Williams, C., Vector boson pair production at the LHC (2011) J. High Energy Phys., 1107
  • Czakon, M., Mitov, A., Top++: a program for the calculation of the top-pair cross-section at hadron colliders (2014) Comput. Phys. Commun., 185, p. 2930
  • Kidonakis, N., NNLL resummation for s-channel single top quark production (2010) Phys. Rev. D, 81
  • Kidonakis, N., Next-to-next-to-leading-order collinear and soft gluon corrections for t-channel single top quark production (2011) Phys. Rev. D, 83
  • Kidonakis, N., Two-loop soft anomalous dimensions for single top quark associated production with a W or H (2010) Phys. Rev. D, 82
  • Martin, A., Stirling, W.J., Thorne, R.S., Watt, G., Parton distributions for the LHC (2009) Eur. Phys. J. C, 63, p. 189
  • Anastasiou, C., Dixon, L.J., Melnikov, K., Petriello, F., High precision QCD at hadron colliders: electroweak gauge boson rapidity distributions at NNLO (2004) Phys. Rev. D, 69
  • Bevilacqua, G., (2013) Comput. Phys. Commun., 184, p. 986
  • Garzelli, M., Kardos, A., Papadopoulos, C., Trocsanyi, Z., Standard model Higgs boson production in association with a top anti-top pair at NLO with parton showering (2011) Europhys. Lett., 96, p. 11001
  • Sjöstrand, T., Mrenna, S., Skands, P., A brief introduction to PYTHIA 8.1 (2008) Comput. Phys. Commun., 178, p. 852
  • Lai, H.-L., New parton distributions for collider physics (2010) Phys. Rev. D, 82
  • Pumplin, J., Stump, D.R., Huston, J., Lai, H.-L., Nadolsky, P.M., Tung, W.K., New generation of parton distributions with uncertainties from global QCD analysis (2012) J. High Energy Phys., 207
  • Nadolsky, P.M., Implications of CTEQ global analysis for collider observables (2008) Phys. Rev. D, 78
  • Summary of ATLAS Pythia 8 tunes https://cds.cern.ch/record/1474107, ATL-PHYS-PUB-2012-003; Nason, P., A new method for combining NLO QCD with shower Monte Carlo algorithms (2004) J. High Energy Phys., 411
  • Frixione, S., Nason, P., Oleari, C., Matching NLO QCD computations with Parton Shower simulations: the POWHEG method (2007) J. High Energy Phys., 711
  • Alioli, S., A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX (2010) J. High Energy Phys., 1006
  • Bahr, M., Herwig++ physics and manual (2008) Eur. Phys. J. C, 58, p. 639
  • Sherstnev, A., Thorne, R., Parton distributions for LO generators (2008) Eur. Phys. J. C, 55, p. 553
  • Gieseke, S., Rohr, C., Siodmok, A., Colour reconnections in Herwig++ (2012) Eur. Phys. J. C, 72, p. 2225
  • Sjöstrand, T., High-energy-physics event generation with Pythia 6.1 (2001) Comput. Phys. Commun., 135, p. 238
  • ATLAS tunes of PYTHIA 6 and PYTHIA8 for MC11 http://cds.cern.ch/record/1363300, ATL-PHYS-PUB-2011-009; Gleisberg, T., Event generation with SHERPA 1.1 (2009) J. High Energy Phys., 902
  • Melia, T., Nason, P., Rontsch, R., Zanderighi, G., W + W − , WZ and ZZ production in the POWHEG BOX (2011) J. High Energy Phys., 1111
  • Binoth, T., Kauer, N., Mertsch, P., Gluon-induced QCD corrections to pp→ZZ→ll¯l ′ l¯ ′ ; Corcella, G., HERWIG 6.5: an event generator for hadron emission reactions with interfering gluons (including supersymmetric processes) (2001) J. High Energy Phys., 101
  • New ATLAS event generator tunes to 2010 data http://cds.cern.ch/record/1345343, ATL-PHYS-PUB-2011-008; Frixione, S., Ridolfi, G., Nason, P., A positive-weight next-to-leading-order Monte Carlo for heavy flavour hadroproduction (2009) J. High Energy Phys., 709
  • Skands, P., Tuning Monte Carlo generators: the Perugia tunes (2010) Phys. Rev. D, 82
  • Re, E., Single-top Wt-channel production matched with parton showers using the POWHEG method (2011) Eur. Phys. J. C, 71, p. 1547
  • Alioli, S., Nason, P., Oleari, C., Re, E., NLO single-top production matched with shower in POWHEG: s- and t-channel contributions (2009) J. High Energy Phys., 909. , Erratum:
  • Mangano, M.L., ALPGEN, a generator for hard multiparton processes in hadronic collisions (2003) J. High Energy Phys., 307
  • Djouadi, A., Kalinowski, J., Spira, M., HDECAY: a program for Higgs boson decays in the standard model and its supersymmetric extension (1998) Comput. Phys. Commun., 108, p. 56
  • Bredenstein, A., Denner, A., Dittmaier, S., Weber, M., Precise predictions for the Higgs-boson decay H→WW/ZZ→ 4 leptons (2006) Phys. Rev. D, 74
  • Actis, S., Passarino, G., Sturm, C., Uccirati, S., NNLO computational techniques: the cases H→γγ and H→gg (2009) Nucl. Phys. B, 811, p. 182
  • Denner, A., Heinemeyer, S., Puljak, I., Rebuzzi, D., Spira, M., Standard model Higgs-boson branching ratios with uncertainties (2011) Eur. Phys. J. C, 71, p. 1753
  • Measurements of normalized differential cross sections for tt¯ production in pp collisions at s=7 TeV using the ATLAS detector (2014) Phys. Rev. D, 90
  • Frixione, S., Laenen, E., Motylinski, P., Webber, B.R., White, C.D., Single-top hadroproduction in association with a W boson (2008) J. High Energy Phys., 807
  • Mangano, M.L., Multijet matrix elements and shower evolution in hadronic collisions: Wbb¯+n jets as a case study (2002) Nucl. Phys. B, 632, p. 343
  • Golonka, P., Wąs, Z., PHOTOS Monte, Carlo: a precision tool for QED corrections in Z and W decays (2006) Eur. Phys. J C, 45, p. 97
  • Stanisław, J., Kühn, J., Wąs, Z., TAUOLA – a library of Monte Carlo programs to simulate decays of polarized τ leptons (1991) Comput. Phys. Commun., 64, p. 275
  • Butterworth, J., Forshaw, J.R., Seymour, M., Multiparton interactions in photoproduction at HERA (1996) Z. Phys. C, 72, p. 637
  • Agostinelli, S., Geant4: a simulation toolkit (2003) Nucl. Instrum. Methods Phys. Res., Sect. A, Accel. Spectrom. Detect. Assoc. Equip., 506, p. 250
  • The ATLAS simulation infrastructure (2010) Eur. Phys. J. C, 70, p. 823
  • The simulation principle and performance of the ATLAS fast calorimeter simulation FastCaloSim http://cds.cern.ch/record/1300517, ATL-PHYS-PUB-2010-013; Further ATLAS tunes of PYTHIA 6 and Pythia 8 https://cds.cern.ch/record/1400677, ATL-PHYS-PUB-2011-014; Electron reconstruction and identification efficiency measurements with the ATLAS detector using the 2011 LHC proton–proton collision data (2014) Eur. Phys. J. C, 74, p. 2941
  • Electron efficiency measurements with the ATLAS detector using the 2012 LHC proton–proton collision data http://cds.cern.ch/record/1706245, ATLAS-CONF-2014-032; Measurement of the muon reconstruction performance of the ATLAS detector using 2011 and 2012 LHC proton–proton collision data (2014) Eur. Phys. J. C, 74, p. 3130
  • Identification and energy calibration of hadronically decaying tau leptons with the ATLAS experiment in pp collisions at s=8 TeV (2014) Eur. Phys. J. C, 75, p. 303
  • Cacciari, M., Salam, G.P., Soyez, G., The anti-k t jet clustering algorithm (2008) J. High Energy Phys., 804
  • Cacciari, M., Salam, G.P., Dispelling the N 3 myth for the k t jet-finder (2006) Phys. Lett. B, 641, p. 57
  • Cacciari, M., Salam, G.P., Soyez, G., FastJet user manual (2012) Eur. Phys. J. C, 72, p. 1896
  • Cojocaru, C., Hadronic calibration of the ATLAS liquid argon end-cap calorimeter in the pseudorapidity region 1.6<|η|<1.8 in beam tests (2004) Nucl. Instrum. Methods Phys. Res., Sect. A, Accel. Spectrom. Detect. Assoc. Equip., 531, p. 481
  • Barillari, T., Local hadronic calibration http://cds.cern.ch/record/1112035, ATL-LARG-PUB-2009-001; Jet energy measurement with the ATLAS detector in proton–proton collisions at s=7 TeV (2013) Eur. Phys. J. C, 73, p. 2304
  • Jet energy resolution in proton–proton collisions at s=7 TeV recorded in 2010 with the ATLAS detector (2013) Eur. Phys. J. C, 73, p. 2306
  • Calibration of the performance of b-tagging for c and light-flavour jets in the 2012 ATLAS data http://cds.cern.ch/record/1741020, ATLAS-CONF-2014-046; Calibration of b-tagging using dileptonic top pair events in a combinatorial likelihood approach with the ATLAS experiment http://cds.cern.ch/record/1664335, ATLAS-CONF-2014-004; Cascioli, F., Maierhöfer, P., Pozzorini, S., Scattering amplitudes with Open Loops (2012) Phys. Rev. Lett., 108
  • Improved luminosity determination in pp collisions at s=7 TeV using the ATLAS detector at the LHC (2013) Eur. Phys. J. C, 73, p. 2518
  • Cowan, G., Cranmer, K., Gross, E., Vitells, O., Asymptotic formulae for likelihood-based tests of new physics (2011) Eur. Phys. J. C, 71, p. 1554. , Erratum:
  • Read, A.L., Presentation of search results: the CL(s) technique (2002) J. Phys. G, 28, p. 2693
  • Measurements of the Higgs boson production and decay rates and coupling strengths using pp collision data at s=7 and 8 TeV in the ATLAS experiment (2015) Eur. Phys. J. C, , submitted to

Citas:

---------- APA ----------
(2015) . Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 749, 519-541.
http://dx.doi.org/10.1016/j.physletb.2015.07.079
---------- CHICAGO ----------
Aad, G. "Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector" . Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 749 (2015) : 519-541.
http://dx.doi.org/10.1016/j.physletb.2015.07.079
---------- MLA ----------
Aad, G. "Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector" . Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, vol. 749, 2015, pp. 519-541.
http://dx.doi.org/10.1016/j.physletb.2015.07.079
---------- VANCOUVER ----------
Aad, G. Search for the associated production of the Higgs boson with a top quark pair in multilepton final states with the ATLAS detector. Phys Lett Sect B Nucl Elem Part High-Energy Phys. 2015;749:519-541.
http://dx.doi.org/10.1016/j.physletb.2015.07.079