相关论文: Bounds on Charged, Stable Superpartners from Cosmi…

In R-parity conserving supersymmetric (SUSY) models the lightest SUSY particle (LSP) is stable and a candidate for dark matter. Depending on the coupling and mass of this particle the life time of the next-to-lightest SUSY particle (NLSP)…

In this paper we study the experimental consequences of a theory which naturally has a heavy, stable (or almost stable) gluino. We define the boundary conditions at a messenger scale $M \sim 10^{14}$ GeV which lead to this alternative…

So far the squarks have not been detected at the LHC indicating that they are heavier than a few hundred GeVs, if they exist. The lighter stop can be considerably lighter than the other squarks. We study the possibility that a…

Many extensions of the Standard Model predict large numbers of additional unstable particles whose decays in the early universe are tightly constrained by observational data. For example, the decays of such particles can alter the ratios of…

Simplified models are a successful way of interpreting current LHC searches for models beyond the standard model (BSM). So far simplified models have focused on topologies featuring a missing transverse energy (MET) signature. However, in…

We draw a possible scenario for the observation of massive long-lived charged particles at the LHC detector ATLAS. The required flexibility of the detector triggers and of the identification and reconstruction systems are discussed. As an…

Supersymmetry is under pressure from LHC searches requiring colored superpartners to be heavy. We demonstrate R-parity violating spectra for which the dominant signatures are not currently well searched for at the LHC. In such cases, the…

A search for stable and long-lived massive particles of electric charge |Q/e| = 1 or 2/3, pair-produced in e+e- collisions at centre-of-mass energies from 130 to 183 GeV, is reported by the OPAL collaboration at LEP. No evidence for…

Hitherto unobserved long-lived massive particles with electric and/or colour charge are predicted by a range of theories which extend the Standard Model. In this paper a search is performed at the ATLAS experiment for slow-moving charged…

Supersymmetry searches at the LHC are both highly varied and highly constraining, but the vast majority are focused on cases where the final-stage visible decays are prompt. Scenarios featuring superparticles with detector-scale lifetimes…

A search for stable and long-lived massive particles of electric charge |Q/e|=1 or fractional charges of 2/3, 4/3, and 5/3 is reported using data collected by the OPAL detector at LEP, at centre-of-mass energies from 130 to 209 GeV. These…

In various models of supersymmetry (SUSY), the lightest superparticle in the minimal SUSY standard model sector, which we call MSSM-LSP, becomes unstable. Then, we may observe the decay of the MSSM-LSP in the detector at the LHC experiment.…

Supersymmetry (SUSY) provides elegant solutions to several open questions in the Standard Model, and searches for SUSY particles are an important component of the LHC physics program. Naturalness arguments favour supersymmetric partners of…

We discuss fluxes of long-lived supersymmetric (SUSY) particles produced in the atmosphere from ultra-high energy cosmic-ray interactions with air nuclei. We consider long-lived particle production which proceeds first via the on-shell…

In supersymmetric (SUSY) theories with extra dimensions the visible energy in sparticle decays can be significantly reduced and its energy distribution broadened, thus significantly weakening the present collider limits on SUSY. The…

We study the phenomenology of a supersymmetric scenario where the next-to-lightest superparticle is the lighter stau and long-lived due to a very weakly coupled lightest superparticle, such as the gravitino. We investigate the LHC…

Colored and colorless particles that are stable on collider scales and carry exotic electric charges, so-called multiply-charged heavy stable particles (MCHSPs), exist in extensions of the Standard Model, and can include the top partner(s)…

Searches for supersymmetry (SUSY) often rely on a combination of hard physics objects (jets, leptons) along with large missing transverse energy to separate New Physics from Standard Model hard processes. We consider a class of…

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…

The Standard Model of particle physics successfully describes the elementary particles and their interactions at low energies, up to 100 GeV. Beyond this scale lies the realm of new physics needed to remedy problems that arise at higher…