Related papers: Probing Light Stops with Stoponium
A search for a resonance heavier than 250 GeV decaying into four leptons via two intermediate bosons is presented. The search uses proton-proton collision data at $\sqrt{s}$ = 13 TeV collected by the CMS experiment, corresponding to an…
LHC searches for BSM resonances in $l^+ l^-, \, jj, \, t\bar{t}, \gamma \gamma$ and $VV$ final states have so far not resulted in discovery of new physics. Current results set lower limits on mass scales of new physics resonances well into…
The discovery of a 125.5 GeV Higgs with standard model-like couplings and naturalness considerations motivate gauge extensions of the MSSM. We analyse two variants of such an extension and carry out a phenomenological study of regions of…
We consider a Minimal Supersymmetric Standard Model scenario in which the only light superparticles are a bino-like dark matter candidate and a nearly-degenerate slepton. It is notoriously difficult to probe this scenario at the Large…
In the Next-to Minimal Supersymmetric Standard Model (NMSSM), a sizable coupling $\lambda$ between the singlet and Higgs fields can naturally accommodate the observed Higgs boson mass of 125 GeV. This large coupling also results in a large…
A search for new physics in proton-proton collisions having final states with an electron or muon and missing transverse energy is presented. The analysis uses data collected in 2012 with the CMS detector, at an LHC center-of-mass energy of…
In order to accommodate the observed Higgs boson mass in the CMSSM, the stops must either be very heavy or the mixing in the stop sector must be very large. Lower stop masses, possibly more accessible at the LHC, still give the correct…
A direct search for new heavy neutral Higgs bosons A and H in the $\mathrm{t\bar{t}}$Z channel is presented, targeting the process pp $\to$ A $\to$ ZH with H $\to$ $\mathrm{t\bar{t}}$. For the first time, the channel with decays of the Z…
A search is performed for heavy resonances decaying to two long-lived massive neutral particles, each decaying to leptons. The experimental signature is a distinctive topology consisting of a pair of oppositely charged leptons originating…
Precision electroweak data, a light higgs and LHC searches for new spin one particles are all very constraining on technicolor models. We use a holographic model of walking techicolor (WTC) gauge dynamics, tuned to produce a light higgs and…
We investigate long-lived particles (LLPs) produced in pair from neutral currents and decaying into a displaced electron plus two jets at the LHC, utilizing the proposed minimum ionizing particle timing detector at CMS. We study two…
We describe a method for searching for a light stop squark [M(stop)+M(LSP)<M(t)] at the Fermilab Tevatron. Traditional searches rely upon stringent background-reducing cuts which, unfortunately, leave very few signal events given the…
We investigate the potential to probe physics beyond the Standard Model with isotope shift measurements of optical atomic clock transitions. We first derive the reach for generic new physics above the GeV scale at the effective field theory…
Compressed mass spectra are generally more difficult to identify than spectra with large splittings. In particular, gluino pair production with four high energy top or bottom quarks leaves a striking signature in a detector. However, if any…
Searches for supersymmetric electroweakinos have entered a crucial phase, as the integrated luminosity of the Large Hadron Collider is now high enough to compensate for their weak production cross-sections. Working in a framework where the…
Light top superpartners play a key role in stabilizing the electroweak scale in supersymmetric theories. For $R$-parity conserved supersymmetric models, traditional searches are not sensitive to the compressed regions. In this paper, we…
With the deeper study of Higgs particle, Higgs precision measurements can be served to probe new physics indirectly. In many new physics models, vector-like quarks $T_L,~T_R$ occur naturally. It is important to probe their couplings with…
We explore the prospects to discover the $h \to Z \gamma$ decay in $t\bar t$-associated production, featuring a signal-to-background ratio of ${\cal O}(1)$. Performing a detailed analysis of the semi-leptonic $t \bar t $-decay channel, we…
A search is presented for rare decays of the Z and Higgs bosons to a photon and a J/$\psi$ or a $\psi$(2S) meson, with the charmonium state subsequentially decaying to a pair of muons. The data set corresponds to an integrated luminosity of…
A search is performed for long-lived particles that decay into final states that include a pair of electrons or a pair of muons. The experimental signature is a distinctive topology consisting of a pair of charged leptons originating from a…