A search for a massive W′ gauge boson decaying to a top quark and a bottom quark is performed with the ATLAS detector in pp collisions at the LHC. The datasetwas taken at a centre-of-mass energy of √s = 8 TeV and corresponds to 20.3 fb−1 of integrated luminosity. This analysis is done in the hadronic decay mode of the top quark, where novel jet substructure techniques are used to identify jets from high-momentum top quarks. This allows for a search for high-mass W′ bosons in the range 1.5-3.0 TeV. b-tagging is used to identify jets originating from b-quarks. The data are consistent with Standard Model background-only expectations, and upper limits at 95\%confidence level are set on the W′ → tb cross section times branching ratio ranging from 0.16 pb to 0.33 pb for left-handed W′ bosons, and ranging from 0.10 pb to 0.21 pb for W′ bosons with purely righthanded couplings. Upper limits at 95\% confidence level are set on the W′-boson coupling to tb as a function of the W′ mass using an effective field theory approach, which is independent of details of particular models predicting a W′ boson. \copyright 2015, CERN for the benefit of the ATLAS collaboration.
Search for W'→tb→qqbb decays in collisions at root s= 8 TeV with the ATLAS detector / Aad, G; Aloisio, Alberto; Alviggi, Mariagrazia; Canale, Vincenzo; Chiefari, Giovanni; DELLA PIETRA, Massimo; DELLA VOLPE, Domenico; Merola, Leonardo; Patricelli, Sergio; Giordano, Raffaele; Conventi, Francesco; Rossi, Elvira; SANCHEZ PINEDA, ARTURO RODOLFO; Carlino, Gianpaolo; DE ASMUNDIS, Riccardo; DI DONATO, Camilla; Doria, Alessandra; Iengo, Paolo; Izzo, Vincenzo; Sekhniaidze, Givi; Et, A. l.. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - 75:4(2015), pp. 1-23. [10.1140/epjc/s10052-015-3372-2]
Search for W'→tb→qqbb decays in collisions at root s= 8 TeV with the ATLAS detector
ALOISIO, ALBERTO;ALVIGGI, MARIAGRAZIA;CANALE, VINCENZO;CHIEFARI, GIOVANNI;DELLA PIETRA, MASSIMO;DELLA VOLPE, DOMENICO;MEROLA, LEONARDO;PATRICELLI, SERGIO;GIORDANO, RAFFAELE;CONVENTI, FRANCESCO;ROSSI, ELVIRA;SANCHEZ PINEDA, ARTURO RODOLFO;CARLINO, GIANPAOLO;DE ASMUNDIS, Riccardo;DI DONATO, CAMILLA;IENGO, PAOLO;IZZO, VINCENZO;
2015
Abstract
A search for a massive W′ gauge boson decaying to a top quark and a bottom quark is performed with the ATLAS detector in pp collisions at the LHC. The datasetwas taken at a centre-of-mass energy of √s = 8 TeV and corresponds to 20.3 fb−1 of integrated luminosity. This analysis is done in the hadronic decay mode of the top quark, where novel jet substructure techniques are used to identify jets from high-momentum top quarks. This allows for a search for high-mass W′ bosons in the range 1.5-3.0 TeV. b-tagging is used to identify jets originating from b-quarks. The data are consistent with Standard Model background-only expectations, and upper limits at 95\%confidence level are set on the W′ → tb cross section times branching ratio ranging from 0.16 pb to 0.33 pb for left-handed W′ bosons, and ranging from 0.10 pb to 0.21 pb for W′ bosons with purely righthanded couplings. Upper limits at 95\% confidence level are set on the W′-boson coupling to tb as a function of the W′ mass using an effective field theory approach, which is independent of details of particular models predicting a W′ boson. \copyright 2015, CERN for the benefit of the ATLAS collaboration.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.