TY - JOUR
T1 - 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
AU - ATLAS Collaboration
AU - Aad, G.
AU - Abbott, B.
AU - Abdallah, J.
AU - Abdinov, O.
AU - Aben, R.
AU - Abolins, M.
AU - AbouZeid, O. S.
AU - Abramowicz, H.
AU - Abreu, H.
AU - Abreu, R.
AU - Abulaiti, Y.
AU - Acharya, B. S.
AU - Adamczyk, L.
AU - Adams, D. L.
AU - Adelman, J.
AU - Adomeit, S.
AU - Adye, T.
AU - Affolder, A. A.
AU - Agatonovic-Jovin, T.
AU - Aguilar-Saavedra, J. A.
AU - Agustoni, M.
AU - Ahlen, S. P.
AU - Ahmadov, F.
AU - Aielli, G.
AU - Akerstedt, H.
AU - Åkesson, T. P.A.
AU - Akimoto, G.
AU - Akimov, A. V.
AU - Alberghi, G. L.
AU - Albert, J.
AU - Albrand, S.
AU - Alconada Verzini, M. J.
AU - Aleksa, M.
AU - Aleksandrov, I. N.
AU - Alexa, C.
AU - Alexander, G.
AU - Alexopoulos, T.
AU - Alhroob, M.
AU - Alimonti, G.
AU - Alio, L.
AU - Alison, J.
AU - Alkire, S. P.
AU - Ashkenazi, A.
AU - Barak, L.
AU - Bella, G.
AU - Cao, T.
AU - Etzion, E.
AU - Oren, Y.
AU - Pitt, M.
AU - Soffer, A.
N1 - Publisher Copyright:
© CERN for the benefit of the ATLAS collaboration 2015.
PY - 2015/7/30
Y1 - 2015/7/30
N2 - A search for the Standard Model Higgs boson produced in association with a top-quark pair, ttH, is presented. The analysis uses 20.3 fb-1 of pp collision data at √s = 8 TeV, collected with the ATLAS detector at the Large Hadron Collider during 2012. The search is designed for the H → bb decay mode and uses events containing one or two electrons or muons. In order to improve the sensitivity of the search, events are categorised according to their jet and b-tagged jet multiplicities. A neural network is used to discriminate between signal and background events, the latter being dominated by tt+jets production. In the single-lepton channel, variables calculated using a matrix element method are included as inputs to the neural network to improve discrimination of the irreducible tt+bb background. No significant excess of events above the background expectation is found and an observed (expected) limit of 3.4 (2.2) times the StandardModel cross section is obtained at 95% confidence level. The ratio of the measured ttH signal cross section to the StandardModel expectation is found to be µ = 1.5±1.1 assuming a Higgs boson mass of 125 GeV.
AB - A search for the Standard Model Higgs boson produced in association with a top-quark pair, ttH, is presented. The analysis uses 20.3 fb-1 of pp collision data at √s = 8 TeV, collected with the ATLAS detector at the Large Hadron Collider during 2012. The search is designed for the H → bb decay mode and uses events containing one or two electrons or muons. In order to improve the sensitivity of the search, events are categorised according to their jet and b-tagged jet multiplicities. A neural network is used to discriminate between signal and background events, the latter being dominated by tt+jets production. In the single-lepton channel, variables calculated using a matrix element method are included as inputs to the neural network to improve discrimination of the irreducible tt+bb background. No significant excess of events above the background expectation is found and an observed (expected) limit of 3.4 (2.2) times the StandardModel cross section is obtained at 95% confidence level. The ratio of the measured ttH signal cross section to the StandardModel expectation is found to be µ = 1.5±1.1 assuming a Higgs boson mass of 125 GeV.
UR - http://www.scopus.com/inward/record.url?scp=84938308942&partnerID=8YFLogxK
U2 - 10.1140/epjc/s10052-015-3543-1
DO - 10.1140/epjc/s10052-015-3543-1
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AN - SCOPUS:84938308942
SN - 1434-6044
VL - 75
SP - 1
EP - 50
JO - European Physical Journal C
JF - European Physical Journal C
IS - 7
M1 - 349
ER -