Multi-lepton signatures of additional scalar bosons beyond the Standard Model at the LHC. (11th October 2018)

• Record Type: Journal Article
• Authors: von Buddenbrock, Stefan; Cornell, Alan S; Mohammed, Abdualazem Fadol; Kumar, Mukesh; Mellado, Bruce; Ruan, Xifeng
• Is Part Of: Journal of physics. Volume 45:Number 11(2018:Nov.)
• Publication Date: 2018-10-11
• Subjects: Higgs boson -- multiple leptons -- heavy scalar -- singlet scalar; Nuclear physics -- Periodicals; Particles (Nuclear physics) -- Periodicals; Physique nucléaire -- Périodiques; Particules (Physique nucléaire) -- Périodiques; Kernfysica; Elementaire deeltjes; 539.7
• DOI: 10.1088/1361-6471/aae3d6
• Languages: English
• ISSNs: 0954-3899

Abstract

Abstract: Following a prediction made in von Buddenbrock et al (2015 arXiv:1506.00612 ), Kumar et al (2017 J. Phys.: Conf. Ser. 802 012007), von Buddenbrock et al (2016 Eur. Phys. J. C76 580), this paper focuses on multi-lepton signatures arising from two new hypothetical scalar bosons, H and S, at the Large Hadron Collider. These two new bosons are an extension to the Standard Model and interact with the SM Higgs boson, h . We consider two production modes for H, one being gluon fusion and the other being in association with top quarks. The H → Sh decay mode is considered, where leptonic final states are studied. The CP properties of S are characterised by considering effective couplings derived from dimension six operators through SWW vertices. The nature of the S boson is considered in two separate contexts. Firstly in a simplified model, it is considered to have Higgs-like couplings. Secondly, we consider a heavy neutrino model and its interactions with the Z, W and S bosons. The predictions of the models are compared both to ATLAS and CMS results at s = 8 and 13 TeV, where appropriate. The data is interpreted using a simplified model where all the signal comes from H → Sh, assuming S to be Higgs-like, m H = 270 GeV and m S = 150 GeV. The combined result yields gives a best fit value for the parameter β g (the strength of the Yukawa coupling of H to top quarks), β g 2 = 1.38 ± 0.22 . A number of regions of the phase space are suggested to the experiments for further exploration.