Search for t(t)over-barH production in the all-jet final state in proton-proton collisions √<i>s</i>=13 TeV



Sirunyan, AM, Tumasyan, A, Adam, W, Ambrogi, F, Asilar, E, Bergauer, T, Brandstetter, J, Brondolin, E, Dragicevic, M, Eroe, J
et al (show 2289 more authors) (2018) Search for t(t)over-barH production in the all-jet final state in proton-proton collisions √<i>s</i>=13 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 2018 (6). pp. 1-45.

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Abstract

<jats:title>A<jats:sc>bstract</jats:sc> </jats:title> <jats:p>A search is presented for the associated production of a Higgs boson with a top quark pair in the all-jet final state. Events containing seven or more jets are selected from a sample of proton-proton collisions at <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \sqrt{s}=13 $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>13</mml:mn> </mml:math> </jats:alternatives> </jats:inline-formula> TeV collected with the CMS detector at the LHC in 2016, corresponding to an integrated luminosity of 35.9 fb<jats:sup>−1</jats:sup>. To separate the <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \mathrm{t}\overline{\mathrm{t}}\mathrm{H} $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mi>H</mml:mi> </mml:math> </jats:alternatives> </jats:inline-formula> signal from the irreducible <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \mathrm{t}\overline{\mathrm{t}}+\mathrm{b}\overline{\mathrm{b}} $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>t</mml:mi> <mml:mover> <mml:mi>t</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mo>+</mml:mo> <mml:mi>b</mml:mi> <mml:mover> <mml:mi>b</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> </jats:alternatives> </jats:inline-formula> background, the analysis assigns leading order matrix element signal and background probability densities to each event. A likelihood-ratio statistic based on these probability densities is used to extract the signal. The results are provided in terms of an observed ttH signal strength relative to the standard model production cross section <jats:italic>μ</jats:italic> = <jats:italic>σ</jats:italic>/<jats:italic>σ</jats:italic> <jats:sub>SM</jats:sub>, assuming a Higgs boson mass of 125 GeV. The best fit value is <jats:inline-formula> <jats:alternatives> <jats:tex-math>$$ \widehat{\mu}=0.9\pm 0.7\left(\mathrm{stat}\right)\pm 1.3\left(\mathrm{syst}\right)=0.9\pm 1.5\left(\mathrm{tot}\right) $$</jats:tex-math> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>μ</mml:mi> <mml:mo>^</mml:mo> </mml:mover> <mml:mo>=</mml:mo> <mml:mn>0.9</mml:mn> <mml:mo>±</mml:mo> <mml:mn>0.7</mml:mn> <mml:mfenced> <mml:mi>stat</mml:mi> </mml:mfenced> <mml:mo>±</mml:mo> <mml:mn>1.3</mml:mn> <mml:mfenced> <mml:mi>syst</mml:mi> </mml:mfenced> <mml:mo>=</mml:mo> <mml:mn>0.9</mml:mn> <mml:mo>±</mml:mo> <mml:mn>1.5</mml:mn> <mml:mfenced> <mml:mi>tot</mml:mi> </mml:mfenced> </mml:math> </jats:alternatives> </jats:inline-formula>, and the observed and expected upper limits are, respectively, <jats:italic>μ</jats:italic> &lt; 3.8 and &lt; 3.1 at 95% confidence levels. </jats:p>

Item Type: Article
Uncontrolled Keywords: Hadron-Hadron scattering (experiments), Higgs physics, Top physics
Depositing User: Symplectic Admin
Date Deposited: 05 Dec 2019 17:17
Last Modified: 13 Oct 2023 02:03
DOI: 10.1007/JHEP06(2018)101
Open Access URL: https://doi.org/10.1007/JHEP06(2018)101
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3065040