Entangling Higgs production associated with a single top and a top-quark pair in the presence of anomalous top-Yukawa coupling
| Autor: | Jung Chang, Jae Sik Lee, Kingman Cheung, Chih-Ting Lu |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Coupling
Physics Nuclear and High Energy Physics Top quark Particle physics Large Hadron Collider 010308 nuclear & particles physics High Energy Physics::Lattice High Energy Physics::Phenomenology Yukawa potential FOS: Physical sciences Quantum entanglement 01 natural sciences High Energy Physics - Experiment High Energy Physics - Experiment (hep-ex) High Energy Physics - Phenomenology High Energy Physics - Phenomenology (hep-ph) 0103 physical sciences Higgs boson lcsh:QC770-798 lcsh:Nuclear and particle physics. Atomic energy. Radioactivity High Energy Physics::Experiment 010306 general physics Phenomenological Models Order of magnitude |
| Zdroj: | Journal of High Energy Physics Journal of High Energy Physics, Vol 2017, Iss 4, Pp 1-28 (2017) |
| Popis: | The ATLAS and CMS collaborations observed a mild excess in the associated Higgs production with a top-quark pair ($t\bar t h$) and reported the signal strengths of $ \mu_{tth}^{\rm ATLAS}=1.81\pm 0.80$ and $\mu_{tth}^{\rm CMS}=2.75\pm 0.99 $ based on the data collected at $\sqrt{s}$= 7 and 8 TeV. Although, at the current stage, there is no obvious indication whether the excess is real or due to statistical fluctuations, here we perform a case study of this mild excess by exploiting the strong entanglement between the associated Higgs production with a single top quark ($thX$) and $t\bar t h$ production in the presence of anomalous top-Yukawa coupling. As well known, $t\bar t h$ production only depends on the absolute value of the top-Yukawa coupling. Meanwhile, in $thX$ production, this degeneracy is lifted through the strong interference between the two main contributions which are proportional to the top-Yukawa and the gauge-Higgs couplings, respectively. Especially, when the relative sign of the top-Yukawa coupling with respect to the gauge-Higgs coupling is reversed, the $thX$ cross section can be enhanced by more than one order of magnitude. We perform a detailed study of the influence of $thX$ production on $t\bar{t}h $ production in the presence of the anomalous top-Yukawa coupling and point out that it is crucial to include $thX$ production in the analysis of the $t\bar t h$ data to pin down the sign and the size of the top-Yukawa coupling in future. While assuming the Standard Model (SM) value for the gauge-Higgs coupling, we vary the top-Yukawa coupling within the range allowed by the current LHC Higgs data. We consider the Higgs decay modes into multileptons, $b\bar b$ and $\gamma\gamma$ putting a particular emphasis on the same sign dilepton events. We also discuss ... Comment: 32 pages, 10 figures, 12 tables, to appear in JHEP |
| Databáze: | OpenAIRE |
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