We report the observation of Higgs boson decays to WW∗ based on an excess over background of 6.1 standard deviations in the dilepton final state, where the Standard Model expectation is 5.8 standard deviations. Evidence for the vector-boson fusion (VBF) production process is obtained with a significance of 3.2 standard deviations. The results are obtained from a data sample corresponding to an integrated luminosity of 25fb-1 from s=7 and 8 TeV pp collisions recorded by the ATLAS detector at the LHC. For a Higgs boson mass of 125.36 GeV, the ratio of the measured value to the expected value of the total production cross section times branching fraction is 1.09-0.15+0.16(stat)-0.14+0.17(syst). The corresponding ratios for the gluon fusion and vector-boson fusion production mechanisms are 1.02$\pm$0.19(stat)-0.18+0.22(syst) and 1.27-0.40+0.44(stat)-0.21+0.30(syst), respectively. At s=8TeV, the total production cross sections are measured to be σ(gg→H→WW∗)=4.6$\pm$0.9(stat)-0.7+0.8(syst)pb and σ(VBFH→WW∗)=0.51-0.15+0.17(stat)-0.08+0.13(syst)pb. The fiducial cross section is determined for the gluon-fusion process in exclusive final states with zero or one associated jet. \copyright 2015 CERN.
Observation and measurement of Higgs boson decays to WW∗ with the ATLAS detector / Aad, G; Aloisio, Alberto; Alviggi, Mariagrazia; Canale, Vincenzo; Chiefari, Giovanni; DELLA PIETRA, Massimo; DELLA VOLPE, Domenico; Merola, Leonardo; Patricelli, Sergio; Conventi, Francesco; Perrella, Sabrina; Rossi, Elvira; SANCHEZ PINEDA, ARTURO RODOLFO; Carlino, Gianpaolo; DE ASMUNDIS, Riccardo; DI DONATO, Camilla; Doria, Alessandra; Iengo, Paolo; Izzo, Vincenzo; Sekhniaidze, Givi; Giordano, Raffaele; Et, A. l.. - In: PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY. - ISSN 1550-7998. - 92:1(2015). [10.1103/PhysRevD.92.012006]
Observation and measurement of Higgs boson decays to WW∗ with the ATLAS detector
ALOISIO, ALBERTO;ALVIGGI, MARIAGRAZIA;CANALE, VINCENZO;CHIEFARI, GIOVANNI;DELLA PIETRA, MASSIMO;DELLA VOLPE, DOMENICO;MEROLA, LEONARDO;PATRICELLI, SERGIO;CONVENTI, FRANCESCO;PERRELLA, SABRINA;ROSSI, ELVIRA;SANCHEZ PINEDA, ARTURO RODOLFO;CARLINO, GIANPAOLO;DE ASMUNDIS, Riccardo;DI DONATO, CAMILLA;IENGO, PAOLO;IZZO, VINCENZO;GIORDANO, RAFFAELE;
2015
Abstract
We report the observation of Higgs boson decays to WW∗ based on an excess over background of 6.1 standard deviations in the dilepton final state, where the Standard Model expectation is 5.8 standard deviations. Evidence for the vector-boson fusion (VBF) production process is obtained with a significance of 3.2 standard deviations. The results are obtained from a data sample corresponding to an integrated luminosity of 25fb-1 from s=7 and 8 TeV pp collisions recorded by the ATLAS detector at the LHC. For a Higgs boson mass of 125.36 GeV, the ratio of the measured value to the expected value of the total production cross section times branching fraction is 1.09-0.15+0.16(stat)-0.14+0.17(syst). The corresponding ratios for the gluon fusion and vector-boson fusion production mechanisms are 1.02$\pm$0.19(stat)-0.18+0.22(syst) and 1.27-0.40+0.44(stat)-0.21+0.30(syst), respectively. At s=8TeV, the total production cross sections are measured to be σ(gg→H→WW∗)=4.6$\pm$0.9(stat)-0.7+0.8(syst)pb and σ(VBFH→WW∗)=0.51-0.15+0.17(stat)-0.08+0.13(syst)pb. The fiducial cross section is determined for the gluon-fusion process in exclusive final states with zero or one associated jet. \copyright 2015 CERN.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
