Publisher: Uppsala universitet, Högenergifysik
Subjects: Subatomic Physics, Subatomär fysik, Physik, ATLAS, QC, 530, Física, Science & Technology, Settore FIS/01 - Fisica Sperimentale, Physics, ATLAS detector; LHC; proton-proton, Settore FIS/04 - Fisica Nucleare e Subnucleare, High Energy Physics - Experiment, Quark, composite Higgs-model; Boson; plus, QC1-999, Nuclear and High Energy Physics
Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAM
A search is performed for the process pp→G*→BHb-/B-Hb→Hbb-→bb-bb-, predicted in composite Higgs scenarios, where G* is a heavy colour octet vector resonance and BH a vector-like quark of charge -1/3. The data were obtained from pp collisions at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.5 fb-1, recorded by the ATLAS detector at the LHC. The largest background, multijet production, is estimated using a data-driven method. No significant excess of events with respect to Standard Model predictions is observed, and upper limits on the production cross section times branching ratio are set. Comparisons to the predictions from a specific benchmark model are made, resulting in lower mass limits in the two-dimensional mass plane of mG* vs. mBH
We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWFW and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COL-CIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Re-public; DNRF and DNSRC, Denmark; IN2P3-CNRS, CEA-DSM/IRFU, France; GNSF, Georgia; BMBF, HGF, and MPG, Germany; GSRT, Greece; RGC, Hong Kong SAR, China; ISF, ICORE and Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; RCN, Norway; MNiSW and NCN, Poland; FCT, Portugal; MNE/IFA, Romania; MES of Russia and NRC KI, Russian Federation; JINR; MESTD, Serbia; MSSR, Slovakia; ARRS and MIZŠ, Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC and Wallenberg Foundation, Sweden; SERI, SNSF and Cantons of Bern and Geneva, Switzerland; MOST, Taiwan; TAEK, Turkey; STFC, United Kingdom; DOE and NSF, United States of America. In addition, individual groups and members have received support from BCKDF, the Canada Council, Canarie, CRC, Compute Canada, FQRNT, and the Ontario Innovation Trust, Canada; EPLANET, ERC, FP7, Horizon 2020 and Marie Skłodowska-Curie Actions, European Union; Investissements d’Avenir Labex and Idex, ANR, Région Auvergne and Fondation Partager le Savoir, France; DFG and AvH Foundation, Germany; Herakleitos, Thales and Aristeia programmes co-financed by EU-ESF and the Greek NSRF; BSF, GIF and Minerva, Israel; BRF, Norway; the Royal Society and Leverhulme Trust, United Kingdom. The crucial computing support from all WLCG partners is acknowledged gratefully, in particular from CERN and the ATLAS Tier-1facilities at TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), CC-IN2P3 (France), KIT/GridKA (Germany), INFN-CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), ASGC (Taiwan), RAL (UK) and BNL (USA) and in the Tier-2 facilities worldwide
The results below are discovered through our pilot algorithms. Let us know how we are doing!
-  M.J. Dugan, H. Georgi, D.B. Kaplan, Anatomy of a composite Higgs model, Nucl. Phys. B 254 (1985) 299.
-  K. Agashe, R. Contino, A. Pomarol, The minimal composite Higgs model, Nucl. Phys. B 719 (2005) 165, arXiv:hep-ph/0412089.
-  R. Contino, Y. Nomura, A. Pomarol, Higgs as a holographic pseudo-Goldstone boson, Nucl. Phys. B 671 (2003) 148, arXiv:hep-ph/0306259.
-  R. Contino, L. Da Rold, A. Pomarol, Light custodians in natural composite Higgs models, Phys. Rev. D 75 (2007) 055014, arXiv:hep-ph/0612048.
-  L. Evans, P. Bryant, LHC machine, J. Instrum. 3 (2008) S08001.
-  D.B. Kaplan, Flavor at SSC energies: a new mechanism for dynamically generated fermion masses, Nucl. Phys. B 365 (1991) 259.
-  R. Contino, et al., Warped/composite phenomenology simplified, J. High Energy Phys. 05 (2007) 074, arXiv:hep-ph/0612180.
-  R. Contino, et al., On the effect of resonances in composite Higgs phenomenology, J. High Energy Phys. 10 (2011) 081, arXiv:1109.1570 [hep-ph].
-  C. Bini, R. Contino, N. Vignaroli, Heavy-light decay topologies as a new strategy to discover a heavy gluon, J. High Energy Phys. 01 (2012) 157, arXiv:1110.6058 [hep-ph].
-  M. Chala, et al., The elusive gluon, J. High Energy Phys. 01 (2015) 092, arXiv: 1411.1771 [hep-ph].
-  ATLAS Collaboration, Search for pair production of heavy top-like quarks decaying to a high-pT W boson and a b quark in the lepton plus jets final state at √s = 7 TeV with the ATLAS detector, Phys. Lett. B 718 (2013) 1284, arXiv:1210.5468 [hep-ex].
-  ATLAS Collaboration, Search for pair and single production of new heavy quarks that decay to a Z boson and a third-generation quark in pp collisions at √s = 8 TeV with the ATLAS detector, J. High Energy Phys. 11 (2014) 104, arXiv:1409.5500 [hep-ex].
-  ATLAS Collaboration, Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in pp collisions at √s = 8 TeV with the ATLAS detector, J. High Energy Phys. 08 (2015) 105, arXiv:1505.04306 [hep-ex].
-  ATLAS Collaboration, Search for vector-like B quarks in events with one isolated lepton, missing transverse momentum and jets at √s = 8 TeV with the ATLAS detector, Phys. Rev. D 91 (2015) 112011, arXiv:1503.05425 [hep-ex].
-  ATLAS Collaboration, 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, J. High Energy Phys. 10 (2015) 150, arXiv:1504.04605 [hep-ex].
-  ATLAS Collaboration, Search for pair production of a new heavy quark that decays into a W boson and a light quark in pp collisions at √s = 8 TeV with the ATLAS detector, Phys. Rev. D 92 (2015) 112007, arXiv:1509.04261 [hepex].
-  ATLAS Collaboration, Search for the production of single vector-like and excited quarks in the W t final state in pp collisions at √s = 8 TeV with the ATLAS, detector, arXiv:1510.02664 [hep-ex], 2015.
-  CMS Collaboration, Inclusive search for a vector-like T quark with charge 2/3 in pp collisions at √s = 8 TeV, Phys. Lett. B 729 (2014) 149, arXiv:1311.7667 [hep-ex].
-  CMS Collaboration, Search for top-quark partners with charge 5/3 in the samesign dilepton final state, Phys. Rev. Lett. 112 (2014) 171801, arXiv:1312.2391 [hep-ex].
-  CMS Collaboration, Search for pair-produced vector-like B quarks in protonproton collisions at √s = 8 TeV, arXiv:1507.07129 [hep-ex], 2015.
-  CMS Collaboration, Search for vector-like charge 2/3 T quarks in proton-proton collisions at √s = 8 TeV, Phys. Rev. D 93 (2016) 012003, arXiv:1509.04177 [hep-ex].
-  CMS Collaboration, Search for vector-like T quarks decaying to top quarks and Higgs bosons in the all-hadronic channel using jet substructure, J. High Energy Phys. 06 (2015) 080, arXiv:1503.01952 [hep-ex].
-  M. Chala, J. Santiago, Hbb production in composite Higgs models, Phys. Rev. D 88 (2013) 035010. We thank M. Chala and J. Santiago for kindly providing the model file and parameter cards.
-  J.P. Araque, N.F. Castro, J. Santiago, Interpretation of vector-like quark searches: heavy gluons in composite Higgs models, J. High Energy Phys. 11 (2015) 120, arXiv:1507.05628 [hep-ph].
-  ATLAS Collaboration, The ATLAS experiment at the CERN large hadron collider, J. Instrum. 3 (2008) S08003.
-  GEANT4 Collaboration, S. Agostinelli, et al., GEANT4: a simulation toolkit, Nucl. Instrum. Methods A 506 (2003) 250.
-  ATLAS Collaboration, The ATLAS simulation infrastructure, Eur. Phys. J. C 70 (2010) 823, arXiv:1005.4568 [hep-ex].
-  J. Alwall, et al., The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations, J. High Energy Phys. 07 (2014) 079, arXiv:1405.0301 [hep-ph].
-  P.M. Nadolsky, et al., Implications of CTEQ global analysis for collider observables, Phys. Rev. D 78 (2008) 013004, arXiv:0802.0007 [hep-ph].
-  J.R. Andersen, et al., Handbook of LHC Higgs Cross Sections: 3 Higgs properties, ed. by S. Heinemeyer et al., CERN-2013-004, FERMILAB-CONF-13-667-T arXiv:1307.1347 [hep-ph], 2013.
-  P. Nason, A new method for combining NLO QCD with shower Monte Carlo algorithms, J. High Energy Phys. 11 (2004) 040, arXiv:hep-ph/0409146.
-  S. Frixione, P. Nason, C. Oleari, Matching NLO QCD computations with Parton Shower simulations: the POWHEG method, J. High Energy Phys. 11 (2007) 070, arXiv:0709.2092 [hep-ph].
-  S. Alioli, et al., A general framework for implementing NLO calculations in shower Monte Carlo programs: the POWHEG BOX, J. High Energy Phys. 06 (2010) 043, arXiv:1002.2581 [hep-ph].
-  T. Sjostrand, S. Mrenna, P.Z. Skands, PYTHIA 6.4 Physics and Manual, J. High Energy Phys. 05 (2006) 026, arXiv:hep-ph/0603175.
-  H.-L. Lai, et al., New parton distributions for collider physics, Phys. Rev. D 82 (2010) 074024, arXiv:1007.2241 [hep-ph].
-  M. Czakon, P. Fiedler, A. Mitov, Total top-quark pair-production cross section at hadron colliders through O (α4S), Phys. Rev. Lett. 110 (2013) 252004, arXiv:1303.6254 [hep-ph].
-  M. Czakon, A. Mitov, Top++: a program for the calculation of the top-pair cross-section at hadron colliders, Comput. Phys. Commun. 185 (2014) 2930, arXiv:1112.5675 [hep-ph].
-  ATLAS Collaboration, Measurements of fiducial cross-sections for tt¯ production with one or two additional b-jets in pp collisions at √s = 8 TeV using the ATLAS detector, Eur. Phys. J. C 76 (2016), arXiv:1508.06868 [hep-ex].
-  T. Gleisberg, et al., Event generation with SHERPA 1.1, J. High Energy Phys. 02 (2009) 007, arXiv:0811.4622 [hep-ph].
-  W. Lampl, et al., Calorimeter clustering algorithms: description and performance, http://cds.cern.ch/record/1099735, 2008.
-  C. Cojocaru, et al., Hadronic calibration of the ATLAS liquid argon end-cap calorimeter in the pseudorapidity region 1.6 < |η| < 1.8 in beam tests, Nucl. Instrum. Methods A 531 (2004) 481, arXiv:physics/0407009.
-  M. Cacciari, G.P. Salam, G. Soyez, The anti-kt jet clustering algorithm, J. High Energy Phys. 04 (2008) 063, arXiv:0802.1189 [hep-ph].
-  ATLAS Collaboration, Data-quality requirements and event cleaning for jets and missing transverse energy reconstruction with the ATLAS detector in protonproton collisions at a center-of-mass energy of √s = 7 TeV, ATLAS-CONF2010-038, http://cdsweb.cern.ch/record/1277678, 2010.
-  ATLAS Collaboration, Jet energy measurement with the ATLAS detector in proton-proton collisions at √s = 7 TeV, Eur. Phys. J. C 73 (2013) 2304, arXiv:1112.6426 [hep-ex].
-  ATLAS Collaboration, Performance of b-jet identification in the ATLAS experiment, arXiv:1512.01094 [hep-ex], 2015.
-  D. Krohn, J. Thaler, L.-T. Wang, Jet trimming, J. High Energy Phys. 02 (2010) 084, arXiv:0912.1342 [hep-ph].
-  ATLAS Collaboration, Performance of jet substructure techniques for large-R jets in proton-proton collisions at √s = 7 TeV using the ATLAS detector, J. High Energy Phys. 09 (2013) 076, arXiv:1306.4945 [hep-ex].
-  S. Catani, et al., Longitudinally invariant kt clustering algorithms for hadronhadron collisions, Nucl. Phys. B 406 (1993) 187.
-  ATLAS Collaboration, Electron performance measurements with the ATLAS detector using the 2010 LHC proton-proton collision data, Eur. Phys. J. C 72 (2012) 1909, arXiv:1110.3174 [hep-ex].
-  ATLAS Collaboration, Measurement of the muon reconstruction performance of the ATLAS detector using 2011 and 2012 LHC proton-proton collision data, Eur. Phys. J. C 74 (2014) 3130, arXiv:1407.3935 [hep-ex].
-  ATLAS Collaboration, Search for Higgs boson pair production in the bb¯bb¯ final state from pp collisions at √s = 8 TeV with the ATLAS detector, Eur. Phys. J. C 75 (2015) 412, arXiv:1506.00285 [hep-ex].
-  ATLAS Collaboration, Jet energy measurement and its systematic uncertainty in proton-proton collisions at √s = 7 TeV with the ATLAS detector, Eur. Phys. J. C 75 (2015) 17, arXiv:1406.0076 [hep-ex].
-  ATLAS Collaboration, Calibration of b-tagging using dileptonic top pair events in a combinatorial likelihood approach with the ATLAS, experiment, ATLASCONF-2014-004, http://cdsweb.cern.ch/record/1664335, 2014.
-  A.L. Read, Presentation of search results: the CL(s) technique, J. Phys. G 28 (2002) 2693.
-  G. Schott, for the RooStats Team, RooStats for searches, arXiv:1203.1547 [physics.data-an], 2012.
No similar publications.