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Related papers: Constraining Top partner and Naturalness at the LH…

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We obtain mass limits on the extra neutral gauge boson which is predicted in a model with hidden gauge symmetry and dynamical breaking of the electroweak symmetry by a top quark condensate. For typical model assumptions, present LEP data…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ralf Bönisch , Arnd Leike

We update the experimental constraints on the parameters of the Higgs effective Lagrangian. We combine the most recent LHC Higgs data in all available search channels with electroweak precision observables from SLC, LEP-1, LEP-2, and the…

High Energy Physics - Phenomenology · Physics 2015-06-15 Adam Falkowski , Francesco Riva , Alfredo Urbano

We present a precise analysis of the Higgs mass corrections stemming from vectorlike top partners in supersymmetric models. We reduce the theoretical uncertainty compared to previous studies in the following aspects: (i) including the…

High Energy Physics - Phenomenology · Physics 2015-08-03 Kilian Nickel , Florian Staub

While current ATLAS and CMS measurements exclude a light charged Higgs ($m_{H^\pm}<160$ GeV) for most of the parameter region in the context of the MSSM scenarios, these bounds are significantly weakened in the Type II 2HDM once the exotic…

High Energy Physics - Phenomenology · Physics 2016-09-29 Felix Kling , Adarsh Pyarelal , Shufang Su

Inclusive Standard Model Higgs boson pair production and subsequent decay to same-sign dileptons via weak gauge W bosons at the CERN Large Hadron Collider has the capability to determine the Higgs boson self-coupling, lambda. The large top…

High Energy Physics - Phenomenology · Physics 2014-11-17 Uli Baur , Tilman Plehn , David Rainwater

We give an explicit example of a composite Higgs model with a pseudo-Nambu-Goldstone Higgs in which the top Yukawa coupling is generated via the partial compositeness mechanism. This mechanism requires composite top partners which are…

High Energy Physics - Phenomenology · Physics 2019-03-27 Helene Gertov , Ann E. Nelson , Ashley Perko , Devin G. E. Walker

We present a fit to the 2012 LHC Higgs data in different supersymmetric frameworks using naturalness as a guiding principle. We consider the MSSM and its D-term and F-term extensions that can raise the tree-level Higgs mass. When adding an…

High Energy Physics - Phenomenology · Physics 2012-12-07 Raffaele Tito D'Agnolo , Eric Kuflik , Marco Zanetti

We assess how different ATLAS and CMS searches for supersymmetry in the $t\bar t + E_T^{\rm miss}$ final state at Run 1 of the LHC constrain scenarios with a fermionic top partner and a dark matter candidate. We find that the efficiencies…

High Energy Physics - Phenomenology · Physics 2016-11-28 Sabine Kraml , Ursula Laa , Luca Panizzi , Hugo Prager

New vectorlike quarks are predicted in many new physics scenarios beyond the Standard Model~(SM) and could potentially be discovered at the LHC. Based on a simplified model including a singlet vectorlike top partner with charge $2/3$, we…

High Energy Physics - Phenomenology · Physics 2022-12-22 Xiao-Min Cui , Yu-Qi Li , Yao-Bei Liu

We present an update of the Standard Model fit to electroweak precision data. We include newest experimental results on the top quark mass, the W mass and width, and the Higgs boson mass bounds from LEP, Tevatron and the LHC. We also…

High Energy Physics - Phenomenology · Physics 2022-07-25 M. Baak , M. Goebel , J. Haller , A. Hoecker , D. Kennedy , K. Moenig , M. Schott , J. Stelzer

The data obtained by the LHC collaborations clearly show that supersymmetric models are not realized in nature in a vanilla form and that in particular strongly interacting supersymmetric particles are most likely heavier than expected. An…

High Energy Physics - Phenomenology · Physics 2016-03-22 Lukas Mitzka , Werner Porod

In the littlest Higgs Model with T-parity, we discuss the pair production of the T-odd top partner ($T_{-}$) which decays almost 100\% into the top quark and the lightest T-odd particle ($A_{H}$). Considering the current constraints, we…

High Energy Physics - Phenomenology · Physics 2019-05-08 Bingfang Yang , Huaying Zhang , Biaofeng Hou , Ning Liu

We study methods of extracting new physics signals in final states with a top-quark pair plus large missing energy at the LHC. We consider two typical examples of such new physics: pair production of a fermionic top partner (a $T'$ in…

High Energy Physics - Phenomenology · Physics 2011-01-13 Tao Han , Rakhi Mahbubani , Devin G. E. Walker , Lian-Tao Wang

In the year 2000 the four LEP experiments collected data at centre-of-mass energies between 200 and 209 GeV, integrating approximately 870 pb-1 of luminosity, with about 510 pb-1 above 206 GeV. The LEP working group for Higgs boson searches…

High Energy Physics - Experiment · Physics 2012-08-27 ALEPH Collaboration , DELPHI Collaboration , L3 Collaboration , OPAL Collaboration , the LEP Higgs Working Group

The Standard Model is a successful theory but lack of a mechanism for neutrino mass generation as well as a solution to the naturalness problem. In the models that are proposed to simultaneously solve the two problems, heavy Majorana…

High Energy Physics - Phenomenology · Physics 2020-10-28 Hang Zhou , Ning Liu

In this note we propose an overview on the current theoretical and experimental limits on a Higgs singlet extension of the Standard Model. We assume that the Boson which has recently been measured by the LHC experiments is the lightest…

High Energy Physics - Phenomenology · Physics 2014-02-25 Giovanni Marco Pruna , Tania Robens

Light top partners are the prime sign of naturalness in composite Higgs models. We explore here the possibility of non-standard top partner phenomenology. We show that even in the simplest extension of the minimal composite Higgs model,…

High Energy Physics - Phenomenology · Physics 2016-01-14 Javi Serra

Recent direct searches for new massive particles place constraints on the free parameters of the Littlest Higgs model. Depending on the choice of model free parameters, the direct search limit on the global symmetry breaking scale f can…

High Energy Physics - Phenomenology · Physics 2008-11-26 John Boersma

Colored fermionic partners of the top quark are well-known signatures of the Composite Higgs scenario and for this reason they have been and will be subject of an intensive experimental study at the LHC. Performing an assessment of the…

High Energy Physics - Phenomenology · Physics 2016-05-04 Oleksii Matsedonskyi , Giuliano Panico , Andrea Wulzer

The Large Electron-Positron (LEP) collider experiments have constrained the mass of the Standard Model (SM) Higgs boson to be above 114.4 GeV. This bound applies to all extensions of the SM where the coupling of a Higgs boson to the Z boson…

High Energy Physics - Phenomenology · Physics 2010-05-25 Alexander Belyaev , Renato Guedes , Stefano Moretti , Rui Santos