Related papers: Light Gluinos at LEP
Future e$^+$e$^-$ colliders, thanks to their clean environment and triggerless operation, offer a unique opportunity to search for long-lived particles (LLPs). Considered in this contribution are promising prospects for LLP searches offered…
Heavy flavour tagging provides a broad range of possibilities in testing QCD features at LEP. We present here a study of 4jets events at LEP I where the so-called light gluinos could be directly produced. We show that microvertex techniques…
We consider supergravity with a gravitino lightest supersymmetric particle. The next-to-lightest supersymmetric particle (NLSP) decays to the gravitino with lifetime naturally in the range 10^4 - 10^8 s. However, cosmological constraints…
We briefly report about a possible settlement of the still ongoing dispute concerning the existence of SUSY signals in 4jet events at LEP1. We base our arguments on a simple selection strategy exploiting secondary vertex tagging and…
The four LEP collaborations have performed searches for supersymmetric particles in light gravitino scenarios, when neutralinos and sleptons are produced and may present measurable decay lengths. The highest energy data has been analysed…
Gluino pair production in an EGRET motivated supersymmetry scenario has been studied. The analysis shows, that this special scenario could be proven with the first LHC data, and assuming a higher integrated luminosity the analysis would be…
Searches for topologies predicted by gauge-mediated SUSY breaking models were performed using data collected with the L3 detector at LEP. All possible lifetimes of the next-to-lightest SUSY particle (NLSP), neutralino or scalar tau, were…
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…
Data collected by the OPAL detector at LEP up to the highest energies of 209 GeV are analyzed to search for evidence of supersymmetric (SUSY) particle production. Chargino pair-production and neutralino associated production are considered…
We discuss the phenomenology of the lightest neutralino in models where an effective bilinear term in the superpotential parametrizes the explicit breaking of R-parity. We consider supergravity scenarios where the lightest supersymmetric…
We study the LHC signal of a light gluino whose cascade decay is dominated by channels involving top, and, sometimes, bottom quarks. This is a generic signature for a number of supersymmetry breaking scenarios considered recently, where the…
Relatively light sneutrinos, which are experimentally allowed, may significantly affect the currently popular search strategies for supersymmetric particles by decaying dominantly into an invisible channel. In certain cases the second…
Many models beyond the Standard Model predict light and feebly interacting particles that are often long-lived. These long-lived particles (LLPs) in many cases can be produced from meson decays. In this work, we propose a simple and quick…
Dark matter pair production at high energy colliders may leave observable signatures in the energy and momentum spectra of the objects recoiling against the dark matter. We discuss signatures of Dark Matter in the jets + missing energy and…
This paper presents a search for direct electroweak gaugino or gluino pair production with a chargino nearly mass-degenerate with a stable neutralino. It is based on an integrated luminosity of 36.1 $\mathrm{fb}^{-1}$ of $pp$ collisions at…
In this note, we advocate a new method for identifying gluino pair production events at the LHC. The method is motivated by and works for theories with heavy squarks and Wino-like LSPs (with nearly degenerate LSP and chargino). Such…
A search for a Higgs boson produced in e^+e^- collisions in association with a Z boson and decaying into invisible particles is performed. Data collected at LEP with the L3 detector at centre-of-mass energies from 189 GeV to 209 GeV are…
Long-lived particles (LLPs) arise in many theories beyond the Standard Model. These may be copiously produced from meson decays (or through their mixing with the LLP) at neutrino facilities and leave a visible decay signal in nearby…
We study the implications at the LHC for the minimal (least) version of the supersymmetric standard model. In this model supersymmetry is broken by gravity and extra gauge interactions effects, providing a spectrum similar in several…
How light can the stop be given current experimental constraints? Can it still be lighter than the top? In this paper, we study this and related questions in the context of gauge-mediated supersymmetry breaking, where a stop NLSP decays…