Related papers: Superlight gravitinos in electron-photon collision…
A search for supersymmetry in events with two or three low-momentum leptons and missing transverse momentum is performed. The search uses proton-proton collisions at $\sqrt{s} =$ 13 TeV collected in the three-year period 2016-2018 by the…
An experimental search for signatures of Kaluza-Klein graviton states at the 500 GeV e+e- linear collider, in which the graviton states are produced in association with a photon, is presented. The study of the signal extraction is performed…
Photonic events with large missing energy have been observed in e+e- collisions at a centre-of-mass energy of 189GeV using the OPAL detector at LEP. Results are presented for event topologies consistent with a single photon or with an…
One way to suppress flavor changing neutral currents or CP violating processes in supersymmetry is to make at least some of the first two generations' scalars superheavy (above ~20 TeV). We summarize the motivations and challenges,…
We simulate precision measurements of gauge-mediated supersymmetry breaking (GMSB) parameters at a 500 GeV e+e- linear collider in the scenario where a neutralino is the next-to-lightest supersymmetric particle. Information on the…
A model of gauge mediation with the gravitino mass of order 1eV is considered to motivate 100TeV colliders. Massive mediators with standard-model and supersymmetry-breaking gauge quantum numbers let low-scale dynamics induce sizable soft…
We study several aspects of supersymmetric models with a $U(1)_R$ symmetry where the Higgs doublet is identified with the superpartner of a lepton. We derive new, stronger bounds on the gaugino masses based on current measurements, and also…
In the light of recent experimental data on gaugino searches, we revisit the direct-transmission model of dynamical supersymmery breaking with the gravitino mass m_{\tilde{G}}\leq 16 eV, which does not have any cosmological or astrophysical…
A search for strongly produced supersymmetric particles is conducted using signatures involving multiple energetic jets and either two isolated leptons ($e$ or $\mu$) with the same electric charge or at least three isolated leptons. The…
The results of a search for new physics in final states with photons and missing transverse energy are reported. The study is based on a sample of proton-proton collisions collected at a center-of-mass energy of 13 TeV with the CMS detector…
A search for supersymmetry is performed in events with a single electron or muon in proton-proton collisions at a center-of-mass energy of 13 TeV. The data were recorded by the CMS experiment at the LHC and correspond to an integrated…
Recent theories propose that quantum gravity effects may be observable at LEP energies via gravitons that couple to Standard Model particles and propagate into extra spatial dimensions. The associated production of a graviton and a photon…
We consider heavy stable neutral particles in the context of supergravity and show that a gravitationally suppressed inflaton decay can produce such particles in cosmologically interesting abundances within a wide mass range $10^3 {\rm GeV}…
Single- and multi-photon events with missing energy are selected in 619/pb of data collected by the L3 detector at LEP at centre-of-mass energies between 189GeV and 209GeV. The cross sections of the process e^+e^- -> nu nu gamma (gamma) are…
A search for strongly produced supersymmetric particles using signatures involving multiple energetic jets and either two isolated same-sign leptons ($e$ or $\mu$), or at least three isolated leptons, is presented. The analysis relies on…
We report the result of a search for scalar leptons in e+e- collisions at 189 GeV centre-of-mass energy at LEP. No evidence for such particles is found in a data sample of 176 pb^{-1}. Improved upper limits are set on the production cross…
We explore the potential of electron-photon colliders to measure fundamental supersymmetry parameters via the processes $e\gamma \to \tilde e \tilde\chi^0$ (selectron-neutralino) and $e\gamma\to \tilde\nu \tilde\chi^-$ (sneutrino-chargino).…
Uncertainties of the MSSM predictions are due to an unknown SUSY breaking mechanism. To reduce these uncertainties, one usually imposes constraints on the MSSM parameter space. Recently, two new constraints became available, both from…
We propose a novel mechanism of electroweak symmetry breaking in supersymmetric models, as the one recently discussed by Birkedal, Chacko and Gaillard, in which the Standard Model Higgs doublet is a pseudo-Goldstone boson of some global…
Chargino pair production via photon-photon collision is investigated in the Minimal Supersymmetric Standard Model at a future linear collider. The process is computed using all the possible diagrams at the next-to-leading order, including…