• Probe Higgs boson pair production via the 3ℓ2j+$\notE$ mode

    分类: 物理学 >> 核物理学 提交时间: 2016-09-13

    摘要: We perform a detailed hadron-level study on the sensitivity of Higgs boson pair production via the WW∗WW∗channel with the final state 3ℓ2j + missing ET at the LHC with the collision energy S√=14 TeV and a future 100 TeV collider. To avoid the huge background from pp→ZW+jets processes, we confine to consider the four lepton patterns: e±e±μ∓ and μ±μ±e∓. We propose a partial reconstruction method to determine the most reliable combination. After that, we examine a few crucial observables which can discriminate efficiently signal and background events, especially we notice that the observable mT2 is very efficient. For the LHC 14 TeV collisions, with an accumulated 3000 fb−1 dataset, we find that the sensitivity of this mode can reach up to 1.5 σ for the Standard Model and the triple coupling of Higgs boson λ3 in the simplest effective theory can be constrained into the range [-1, 8] at 95% confidence level; at a 100 TeV collider with the integrated luminosity 3000 fb−1, the sensitivity can reach up to 13 σ for the Standard Model and we find that all values of λ3 in the effective theory can be covered up to 3σ even without optimising signals. To precisely measure the triple coupling of Higgs boson λ3=1 of the Standard Model at a 100 TeV collider, by using the invariant mass of three leptons which is robust to against the contamination of underlying events and pileup effects and by performing a χ2 analysis, we find that it can be determined into a range [0.8, 1.5] at 95% confidence level.

  • Discovery potential of Higgs boson pair production through 4$\ell$+$E\!\!/$ final states at a 100 TeV collider

    分类: 物理学 >> 核物理学 提交时间: 2016-09-02

    摘要: We explore the discovery potential of Higgs pair production at a 100 TeV collider via full leptonic mode. The same mode can be explored at the LHC when Higgs pair production is enhanced by new physics. We examine two types of fully leptonic final states and propose a partial reconstruction method. The reconstruction method can reconstruct some kinematic observables. It is found that the mT2 variable determined by this reconstruction method and the reconstructed visible Higgs mass are important and crucial to discriminate the signal and background events. It is also noticed that a new variable, denoted as Δm which is defined as the mass difference of two possible combinations, is very useful as a discriminant. We also investigate the interplay between the direct measurements of tt¯h couplings and other related couplings and trilinear Higgs coupling at hadron colliders and electron-positron colliders.