相关论文: Boosted Semileptonic Tops in Stop Decays
We have searched for the supersymmetric partner of the top quark (stop) in 107 pb^{-1} of p-pbar collisions at \sqrt{s}= 1.8 TeV collected by the Collider Detector at Fermilab (CDF). Within the framework of the Minimal Supersymmetric…
A light supersymmetric top quark partner (stop) with a mass nearly degenerate with that of the Standard Model (SM) top quark can evade direct searches. The precise measurement of SM top properties such as the cross-section has been…
The discovery of the top quark, the most massive elementary particle yet known, has given us a distinct window into investigating the physics of the Standard Model and Beyond. With a plethora of top quarks to be produced in the High…
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…
In the context of prospective studies for searches of new physics at the LHC Run 3, this paper investigates the relevance of using top quarks produced from new long-lived particles, and detected in the tracker volume of the ATLAS and CMS…
Vector-like top partners with electric charge $+2/3$ are predicted in many extensions of the Standard Model and are actively searched for at the LHC through their electroweak decays $T\to Wb$, $Zt$, and $Ht$. More general scenarios,…
A search is conducted for new phenomena in events with a top quark pair and large missing transverse momentum, where the top quark pair is reconstructed in final states with one isolated electron or muon and multiple jets. The search is…
Searches for new low-mass matter and mediator particles have actively been pursued at fixed target experiments and at $e^+e^-$ colliders. It is challenging at the CERN LHC, but they have been searched for in Higgs boson decays and in $B$…
Searches for new physics in high-multiplicity events with little or no missing energy are an important component of the LHC program, complementary to analyses that rely on missing energy. We consider the potential reach of searches for…
Many theories beyond the Standard Model predict new phenomena which decay to well isolated, high-$p_{\text{T}}$ leptons. Searches for new physics with these signatures are performed using the ATLAS experiment at the LHC. The results…
The results of a search for vector-like top quarks using events with exactly one lepton, at least four jets, and large missing transverse momentum are reported. The search is optimised for pair production of vector-like top quarks in the…
The possibility of a vectorlike top partner decaying to a new colourless weak-singlet scalar or pseudoscalar has attracted some attention in the literature. We investigate the production of a weak-singlet charge-$2/3$ $T$ quark that can…
Low energy supersymmetric models provide a solution to the hierarchy problem and also have the necessary ingredients to solve two of the most outstanding issues in cosmology: the origin of the baryon asymmetry and the source of dark matter.…
Identification of boosted, hadronically-decaying top quarks is a problem of central importance for physics goals of the Large Hadron Collider. We present a theoretical analysis of top quark tagging, establishing zeroth-order, minimal…
A search for pair-produced vector-like quarks using events with exactly one lepton ($e$ or $\mu$), at least four jets including at least one $b$-tagged jet, and large missing transverse momentum is presented. Data from proton-proton…
In time for the first tests on LHC data we introduce a set of improvements and tests of purely kinematic top tagging algorithms. First, we show how different jet algorithms can be used for different transverse momentum regimes. Combining…
In this work, we have considered an extension of the standard model (SM) with a $SU(2)_L$ singlet vectorlike quark (VLQ) with electric charge $Q=+2/3$. The model also contains an additional local $U(1)_d$ symmetry group and the…
Precise measurements of the properties of the top quark test the Standard Model (SM) and can be used to constrain new physics models. The top quark pair charge asymmetry is an asymmetry predicted to occur beyond leading-order QCD in the SM,…
Supersymmetric spectra with a stop NLSP and a neutralino or gravitino LSP present a special challenge for collider searches. For stop pairs directly produced from QCD, the visible final-state particles are identical to those of top quark…
A search is performed for pair-produced spin-3/2 excited top quarks (t* t*-bar), each decaying to a top quark and a gluon. The search uses data collected with the CMS detector from pp collisions at a center-of-mass energy of sqrt(s) = 8…