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Title: 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

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 19.5fb -1 collected by the CMS experiment at the LHC in pp collisions at a centre-of-mass energy of 8TeV. In order to separate the signal from the larger tt¯ + 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, μ, relative to the standard model prediction for a Higgs boson mass of 125GeV. The observed (expected) exclusion limit at a 95 % confidence level is μ < 4.2 (3.3), corresponding to a best fit value μ^ = 1.2 +1.6 -1.5.

Authors:
 [1]
  1. Yerevan Physics Inst. (YerPhI), Yerevan (Armenia). et al.
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Org.:
CMS Collaboration
OSTI Identifier:
1221254
Report Number(s):
FERMILAB-PUB-15-072-CMS; CERN-PH-EP-2015-016; CMS-HIG-14-010
Journal ID: ISSN 1434-6052; arXiv eprint number arXiv:1502.02485
Grant/Contract Number:  
AC02-07CH11359
Resource Type:
Accepted Manuscript
Journal Name:
European Physical Journal. C, Particles and Fields (Online)
Additional Journal Information:
Journal Name: European Physical Journal. C, Particles and Fields (Online); Journal Volume: 75; Journal Issue: 6; Journal ID: ISSN 1434-6052
Publisher:
Springer
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS

Citation Formats

Khachatryan, Vardan. 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. United States: N. p., 2015. Web. doi:10.1140/epjc/s10052-015-3454-1.
Khachatryan, Vardan. 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. United States. doi:10.1140/epjc/s10052-015-3454-1.
Khachatryan, Vardan. Tue . "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". United States. doi:10.1140/epjc/s10052-015-3454-1. https://www.osti.gov/servlets/purl/1221254.
@article{osti_1221254,
title = {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},
author = {Khachatryan, Vardan},
abstractNote = {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 19.5fb-1 collected by the CMS experiment at the LHC in pp collisions at a centre-of-mass energy of 8TeV. In order to separate the signal from the larger tt¯ + 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, μ, relative to the standard model prediction for a Higgs boson mass of 125GeV. The observed (expected) exclusion limit at a 95 % confidence level is μ < 4.2 (3.3), corresponding to a best fit value μ^ = 1.2+1.6-1.5.},
doi = {10.1140/epjc/s10052-015-3454-1},
journal = {European Physical Journal. C, Particles and Fields (Online)},
number = 6,
volume = 75,
place = {United States},
year = {2015},
month = {6}
}

Journal Article:
Free Publicly Available Full Text
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Citation Metrics:
Cited by: 22 works
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Figures / Tables:

Fig. 1 Fig. 1 : Tree-level Feynman diagrams contributing to the partonic processes: left q$\bar{q}$ → t$\bar{t}$H, centre gg → t$\bar{t}H, and right gg → t$\bar{t} + b$\bar{b}

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    Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.