Search for the Standard Model Higgs boson in association with top quarks and decaying to b at = 7 TeV using the ATLAS detector

5th International Workshop on Top Quark Physics

Nackenhorst, Olaf^1

II. Institute of Physics, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, D-37077 Gottingen, Germany^1

关键词: ATLAS detectors;    Background prediction;    Integrated luminosity;    Pp collisions;    Semileptonic decay;    Systematic uncertainties;    The standard model;    Upper limits;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/452/1/012057/pdf
DOI  :  10.1088/1742-6596/452/1/012057

来源: IOP

【 摘 要 】

A search for a Higgs boson produced in association with a pair of top quarks and decaying into apair of b quarks is presented. The analysis uses an integrated luminosity of 4.7 fb-1of pp collisions at a center-of-mass energy of = 7 TeV collected in 2011 with the ATLAS detector at the LHC. The search is focused on the semileptonic decay of the t system and combines nine different topologies given by the jet and b-tagged jet multiplicities of the event. A kinematic reconstruction of the Higgs boson mass is performed in the signal enhanced region, which becomes the primary discriminant variable between signal and background. Background-dominated samples are exploited to constrain the leading systematic uncertainties affecting the background prediction. No significant excess of events above the background expectation is observed. For a Higgs boson with a mass of 125 GeV, an observed (expected) 95% confidence upper limit of 13.1 (10.5) times the Standard Model cross section is obtained.