Related papers: Virtual LSPs at e+ e- Colliders
Supersymmetry may resolve the disagreement between the precision electroweak data and the direct limit on the higgs mass, if there are light sneutrinos in the mass range 55 GeV $ < m_{\snu} < $ 80 GeV. Such sneutrinos should decay invisibly…
A low-scale neutrino seesaw may be probed or even reconstructed at colliders provided that supersymmetry is at the weak scale and the LSP is a sterile sneutrino. Because the neutrino Yukawa couplings are small, the NLSP is typically…
It was shown in a previous study that a lightest neutralino with mass below 30 GeV was severely constrained in the minimal supersymmetric standard model (MSSM), unless it annihilates via a light stau and thus yields the observed dark matter…
We explore the dark matter detection prospects in the Minimal Supersymmetric Standard Model in the scenario where the scalar partners of the fermions and the Higgs particles (except for the Standard-Model-like one) are assumed to be very…
We study supersymmetric scenarios where the dark matter is the gaugino of an unbroken hidden U(1) which interacts with the visible world only via a small kinetic mixing with the hypercharge. Strong constraints on the parameter space can be…
We suggest that supersymmetric dark matter be used to set the energy scale of a linear $e^+ e^-$ collider. Assuming that the lightest supersymmetric particle (LSP) is a stable neutralino $\chi$, as in many incarnations of the MSSM with…
Within the framework of the Next-To-Minimal Supersymmetric Standard Model (NMSSM) we study neutralino production $e^+e^- \longrightarrow \tilde{\chi}^0_i \tilde{\chi}^0_j$ ($i,j=1,\ldots ,5$) at center-of-mass energies between 100 and 600…
We study the possibility of a light Dark Matter (DM) within a constrained Minimal Supersymmetric Standard Model (cMSSM) framework augmented by a SM singlet-pair sector to account for the non-zero neutrino masses by inverse seesaw mechanism.…
A search for charginos and neutralinos, predicted by supersymmetric theories, has been performed using a data sample of 10.3 pb^-1 at centre-of-mass energies of sqrt(s) = 170 and 172 GeV with the OPAL detector at LEP. No evidence for these…
We search for inclusive high $E_T$ diphoton events with large missing transverse energy in $p\bar{p}$ collisions at $\sqrt{s}$=1.8 TeV. Such events are expected from pair production of charginos and neutralinos within the framework of the…
Under R-parity, the lightest supersymmetric particle (LSP) is stable and may serve as a good dark matter candidate. The R-parity can be naturally introduced with a gauge origin at TeV scale. We go over why a TeV scale B-L gauge extension of…
We consider a scenario inspired by natural supersymmetry, where neutrino data is explained within a low-scale seesaw scenario. We extend the Minimal Supersymmetric Standard Model by adding light right-handed neutrinos and their…
DELPHI data collected at centre-of-mass energies up to 208 GeV have been analysed to search for charginos, neutralinos and sfermions in the framework of the Minimal Supersymmetric Standard Model (MSSM) with R-parity conservation. No…
We consider supersymmetric models in which sneutrinos are viable dark matter candidates. These are either simple extensions of the Minimal Supersymmetric Standard Model with additional singlet superfields, such as the inverse or linear…
In this talk I discuss some scenarios which involve small extensions of the ideas usually considered in the Minimal Supersymmetric Standard Model (MSSM). I present results of a study of the implication of non-universal gaugino masses (NGM)…
A two-component dark matter model is studied adopting the degenerate scenario in the R-parity conserving NMSSM. The gravitino LSP and the neutralino NLSP are extremely degenerate in mass, avoiding the BBN bounds and obtaining a high…
We revisit the case of a light neutralino LSP in the framework of the MSSM. We consider a model with eleven free parameters. We show that all scenarios where the annihilation of light neutralinos rely mainly on the exchange of a light…
In minimal supergravity based supersymmetry models the charged sleptons as well as the sneutrinos may be lighter than the squarks. In such light slepton scenario the search for lighter stop squark has been investigated in the dilepton +…
The neutralino, the lightest stable supersymmetric particle, is a strong theoretical candidate for the missing astronomical "dark matter". Depending on their annihilation cross section, relic neutralinos from early formation of the Universe…
The electroweak (EW) sector of the Minimal Supersymmetric Standard Model (MSSM) can account for a variety of experimental data. The lighest supersymmetric particle (LSP), which we take as the lightest neutralino, $\tilde \chi_1^0$, can…