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$0.9(stat)-0.7+0.8(syst)pb and σ(VBFH→WW∗)=0.51-0.15+0.17(stat)-0.08+0.13(syst)pb. The fiducial cross section is determined for the gluon-fusion process in exclusive final states with zero or one associated jet. \copyright 2015 CERN.
Observation and measurement of Higgs boson decays to WW∗ with the ATLAS detector / Aad, G., Aloisio, A., Alviggi, M., Canale, V., Chiefari, G., DELLA PIETRA, M., DELLA VOLPE, D., Merola, L., Patricelli, S., Conventi, F., Perrella, S., Rossi, E., SANCHEZ PINEDA, A.R., Carlino, G., DE ASMUNDIS, R., DI DONATO, C., Doria, A., Iengo, P., Izzo, V., Sekhniaidze, G., et al.. - In: PHYSICAL REVIEW D, PARTICLES, FIELDS, GRAVITATION, AND COSMOLOGY. - ISSN 1550-7998. - 92:1(2015). [10.1103/PhysRevD.92.012006]
Observation and measurement of Higgs boson decays to WW∗ with the ATLAS detector
ALOISIO, ALBERTO;ALVIGGI, MARIAGRAZIA;CANALE, VINCENZO;CHIEFARI, GIOVANNI;DELLA PIETRA, MASSIMO;DELLA VOLPE, DOMENICO;MEROLA, LEONARDO;PATRICELLI, SERGIO;CONVENTI, FRANCESCO;PERRELLA, SABRINA;ROSSI, ELVIRA;SANCHEZ PINEDA, ARTURO RODOLFO;CARLINO, GIANPAOLO;DE ASMUNDIS, Riccardo;DI DONATO, CAMILLA;IENGO, PAOLO;IZZO, VINCENZO;GIORDANO, RAFFAELE;
2015
Abstract
We report the observation of Higgs boson decays to WW∗ based on an excess over background of 6.1 standard deviations in the dilepton final state, where the Standard Model expectation is 5.8 standard deviations. Evidence for the vector-boson fusion (VBF) production process is obtained with a significance of 3.2 standard deviations. The results are obtained from a data sample corresponding to an integrated luminosity of 25fb-1 from s=7 and 8 TeV pp collisions recorded by the ATLAS detector at the LHC. For a Higgs boson mass of 125.36 GeV, the ratio of the measured value to the expected value of the total production cross section times branching fraction is 1.09-0.15+0.16(stat)-0.14+0.17(syst). The corresponding ratios for the gluon fusion and vector-boson fusion production mechanisms are 1.02$\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.
