English
Related papers

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

200 papers

In the littlest Higgs model with T-parity(LHT), we study the single production of vector-like top partner with the subsequent decay $T_{+}\to Wb$ in the leptonic channel at the $ep$ colliders. Focus on the LHeC ($ \sqrt{s} $ = 1.98 TeV) and…

High Energy Physics - Phenomenology · Physics 2019-05-22 Bingfang Yang , Biaofeng Hou , Huaying Zhang , Ning Liu

The results of a search for direct pair production of heavy top-quark partners in 4.7 fb-1 of integrated luminosity from pp collisions at sqrt(s) = 7 TeV collected by the ATLAS detector at the LHC are reported. Heavy top-quark partners…

High Energy Physics - Experiment · Physics 2013-06-24 ATLAS Collaboration

Fermionic top partners are a feature of many models of physics beyond the Standard Model. We propose a search strategy for single production of top partners focussing specifically on the dominant decay to $Wb$. The enormous background can…

High Energy Physics - Phenomenology · Physics 2014-10-16 Nicolas Gutierrez Ortiz , James Ferrando , Deepak Kar , Michael Spannowsky

In the littlest Higgs model with T-parity, we study associated production of a Higgs and a single top quark at the 14 TeV LHC. We focus on the Higgs to two photons decay and the semileptonic top decay channel. By performing a fast detector…

High Energy Physics - Phenomenology · Physics 2018-04-04 Bingfang Yang , Biaofeng Hou , Huaying Zhang

We analyze the corrections to the precision EW observables in minimal composite Higgs models by using a general effective parametrization which also includes the lightest fermionic resonances. A new, possibly large, logarithmically…

High Energy Physics - Phenomenology · Physics 2015-06-16 Christophe Grojean , Oleksii Matsedonskyi , Giuliano Panico

Theories of physics beyond the Standard Model that address the hierarchy problem generally involve top partners, new particles that cancel the quadratic divergences associated with the Yukawa coupling of the Higgs to the top quark. With…

High Energy Physics - Phenomenology · Physics 2015-03-11 Gustavo Burdman , Zackaria Chacko , Roni Harnik , Leonardo de Lima , Christopher B. Verhaaren

We analyse the fine-tuning constraints arising from absence of superpartners at LEP, without strong universality assumptions. We show that such constraints do not imply that charginos or neutralinos should have been seen at LEP, contrary to…

High Energy Physics - Phenomenology · Physics 2011-05-05 G. L. Kane , S. F. King

We study the phenomenology of vector resonances in the context of natural composite Higgs models. A mild hierarchy between the fermionic partners and the vector resonances can be expected in these models based on the following arguments.…

High Energy Physics - Phenomenology · Physics 2015-06-23 Mikael Chala , Jose Juknevich , Gilad Perez , Jose Santiago

We investigate the implications of the Higgs rate measurements from Run 1 of the LHC for the mass of the light scalar top partner (stop) in the Minimal Supersymmetric Standard Model (MSSM). We focus on light stop masses, and we decouple the…

High Energy Physics - Phenomenology · Physics 2016-12-22 Stefan Liebler , Stefano Profumo , Tim Stefaniak

The Littlest Higgs model with T-parity is providing an attractive solution to the fine-tuning problem. This solution is only entirely natural if its intrinsic symmetry breaking scale f is relatively close to the electroweak scale. We…

High Energy Physics - Phenomenology · Physics 2014-02-21 Jürgen Reuter , Marco Tonini , Maikel de Vries

We consider an extension of the MSSM with an added vectorlike top partner. Our aim is to revisit to what extent such an extension can raise the Higgs boson mass through radiative corrections and help ameliorate the MSSM hierarchy problem,…

High Energy Physics - Phenomenology · Physics 2015-06-02 Zygmunt Lalak , Marek Lewicki , James D. Wells

In composite Higgs models with partial compositeness, the small value of the observed Higgs mass implies the existence of light fermionic resonances, the top partners, whose quantum numbers are determined by the symmetry (and symmetry…

High Energy Physics - Phenomenology · Physics 2015-06-18 Oleksii Matsedonskyi , Francesco Riva , Thibaud Vantalon

Relatively light Top Partners are unmistakable signatures of reasonably Natural Composite Higgs models and as such they are worth searching for at the LHC. Their phenomenology is characterized by a certain amount of model-dependence, which…

High Energy Physics - Phenomenology · Physics 2015-06-22 Oleksii Matsedonskyi , Giuliano Panico , Andrea Wulzer

In composite Higgs models light fermionic top partners often play an important role in obtaining a 126 GeV Higgs mass. The presence of these top partners implies that coloured vector mesons, or massive gluon partners, most likely exist.…

High Energy Physics - Phenomenology · Physics 2015-06-16 James Barnard , Tony Gherghetta , Anibal Medina , Tirtha Sankar Ray

We consider how best to search for top partners in generic composite Higgs models. We begin by classifying the possible group representations carried by top partners in models with and without a custodial $SU(2)\times SU(2) \rtimes…

High Energy Physics - Phenomenology · Physics 2014-12-16 Ben Gripaios , Thibaut Mueller , M. A. Parker , Dave Sutherland

Direct searches for superpartners and precision measurements of the properties of the $\sim 126$ GeV Higgs boson lead to important inter-dependent constraints on the underlying parameter space of the MSSM. The 19/20-parameter…

High Energy Physics - Phenomenology · Physics 2013-10-02 Matthew Cahill-Rowley , JoAnne Hewett , Ahmed Ismail , Tom Rizzo

We study the Littlest Higgs model with T-parity at the LHC through pair productions of the T-odd top quark partner (T_-) which decays into the top quark and the lightest T-odd particle. We identify the region of parameters favored by the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Shigeki Matsumoto , Mihoko M. Nojiri , Daisuke Nomura

Vector-like top partner plays a central role in many new physics models which attempt to address the hierarchy problem. The top partner is conventionally assumed to decay to a quark and a SM boson. However, it is also possible that the top…

High Energy Physics - Phenomenology · Physics 2021-06-23 Daohan Wang , Lei Wu , Mengchao Zhang

Searches for new fermionic states heavier than the top quark are being pursued by the CMS & ATLAS collaborations, pushing the mass bounds towards the TeV scale. Although a chiral fourth generation of quarks is now excluded by the LHC…

High Energy Physics - Phenomenology · Physics 2014-05-13 Mathieu Buchkremer

Solutions to the electroweak hierarchy problem typically introduce a new symmetry to stabilize the quadratic ultraviolet sensitivity in the self-energy of the Higgs boson. The new symmetry is either broken softly or collectively, as for…

High Energy Physics - Phenomenology · Physics 2017-10-25 Chuan-Ren Chen , Jan Hajer , Tao Liu , Ian Low , Hao Zhang