Search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks using a matrix element method

CMS;Basegmez, Suzan;Beluffi, Camille;Bruno, Giacomo;Bethani, Agni;et.al.
(2015) European Physical Journal C. Particles and Fields — Vol. C75, p. 251 (2015)

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Authors
  • CMSUCLouvain
    Author
  • Basegmez, SuzanUCLouvain
    Author
  • Beluffi, CamilleUCLouvain
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  • Author
  • Castello, RobertoUCLouvain
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  • Caudron, AdrienUCLouvain
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  • Ceard, LudivineUCLouvain
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  • Da Silveira, Gustavo GilUCLouvain
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  • Author
  • Du Pree, TristanUCLouvain
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  • Favart, DenisUCLouvain
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  • Forthomme, LaurentUCLouvain
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  • Author
  • Hollar, JonathanUCLouvain
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  • Jafari, AbidehUCLouvain
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  • Jez, PavelUCLouvain
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  • Komm, MatthiasUCLouvain
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  • Author
  • Nuttens, ClaudeUCLouvain
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  • Pagano, DavideUCLouvain
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  • Perrini, LuciaUCLouvain
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  • Pin, ArnaudUCLouvain
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  • Piotrzkowski, KrzysztofUCLouvain
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  • Popov, AndreyUCLouvain
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  • Quertenmont, LoïcUCLouvain
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  • Selvaggi, MicheleUCLouvain
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  • Vidal Maroño, MiguelUCLouvain
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  • Vizan Garcia, Jesús ManuelUCLouvain
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  • Bethani, Agniorcid-logoUCLouvain
    Author
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Abstract
A search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks is presented. Events with hadronic jets and one or two oppositely charged leptons are selected from a data sample corresponding to an integrated luminosity of 19.5 inverse femtobarns collected by the CMS experiment at the LHC in pp collisions at a centre-of-mass energy of 8 TeV. In order to separate the signal from the larger t t-bar + jets background, this analysis uses a matrix element method that assigns a probability density value to each reconstructed event under signal or background hypotheses. The ratio between the two values is used in a maximum likelihood fit to extract the signal yield. The results are presented in terms of the measured signal strength modifier, mu, relative to the standard model prediction for a Higgs boson mass of 125 GeV. The observed (expected) exclusion limit at a 95% confidence level is mu < 4.2 (3.3), corresponding to a best fit value mu-hat = 1.2 +1.6 -1.5.
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Citations

CMS, Basegmez, S., Beluffi, C., Bruno, G., Castello, R., Caudron, A., Ceard, L., Da Silveira, G. G., Delaere, C., Du Pree, T., Favart, D., Forthomme, L., Giammanco, A., Hollar, J., Jafari, A., Jez, P., Komm, M., Lemaitre, V., Nuttens, C., et al. (2015). Search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks using a matrix element method. European Physical Journal C. Particles and Fields, C75, 251. https://doi.org/10.1140/epjc/s10052-015-3454-1 (Original work published 2015)