Related papers: Light Neutralinos in B-Decays
We analyze higher order decay modes of the lightest top squark $\tilde{t}_1$ in the Minimal Supersymmetric extension of the Standard Model (MSSM), where the lightest SUSY particle (LSP) is assumed to be the neutralino $\chi_1^0$. For small…
The modest addition of the dimension-5 term lambda(H_u.H_d)^2/M to the superpotential of the minimal supersymmetric standard model (MSSM) originated from physics beyond the MSSM (BMSSM) has a significant impact on the scenario of the…
We study the implications of a large baryogenesis temperature, $T_B = O(10^{10}$ GeV), on the mass spectrum of superparticles in supersymmetric extensions of the standard model. Models with a neutralino as lightest superparticle (LSP) are…
Results are presented for the two-body decays of mesons into light neutralinos and from the first complete calculation of the loop-induced decays of kaons to pions plus light neutralinos and of B mesons to kaons plus light neutralinos. The…
Neutralino dark matter is generally assumed to be relatively heavy, with a mass near the electroweak scale. This does not necessarily need to be the case, however. In the Next-to-Minimal Supersymmetric Standard Model (NMSSM) and other…
We evaluate two-body decay modes of neutralinos in the Minimal Supersymmetric Standard Model with complex parameters (cMSSM). Assuming heavy scalar quarks we take into account all two-body decay channels involving charginos, neutralinos,…
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…
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…
We examine various predictions of the minimal supersymmetric standard model coupled to minimal supergravity. The model is characterised by a small set of parameters at the unification scale. The supersymmetric particle spectrum at low…
A constraint from $b\rightarrow s\gamma$ process to the minimal supersymmetric standard model is derived in the light stop region where the coupling between the lighter stop and the $Z^0$ boson vanishes due to the left-right mixing of the…
We show that in the Minimal Supersymmetric Standard Model, the mass of the lightest neutralino is experimentally unconstrained if the GUT relation between the gaugino mass parameters M_1 and M_2 is dropped. We discuss what the impact of…
Searches for supersymmetric particles at LEP are first reviewed, with some emphasis on the mass limit for the lightest neutralino. The framework is the MSSM with R-parity conservation, with brief excursions towards mSUGRA and GMSB. Next,…
We show that the late-decaying particle scenario may be realized in the supersymmetric singlet majoron model with the majoron scale $10-200$ TeV. The smajoron decaying into two neutrinos is the late-decaying particle with the mass $0.1-1$…
Supersymmetric (SUSY) standard models in which the lightest SUSY particle (LSP) is an ultralight gravitino (m_{3/2}=O(1) eV) are very attractive, since they are free from the cosmological gravitino problems. If the neutralino is the next…
The possibility that both the baryon asymmetry and dark matter arise from the late decay of a population of supersymmetric particles is considered. If the decay takes place below the LSP freeze out temperature, a nonthermal distribution of…
We consider a mechanism for neutrino mass generation, based on a local B-L extension of the standard model, which becomes a linear seesaw regime for light neutrinos after spontaneous symmetry breaking. The spectrum of extra particles…
In this work, we present mass limits on gluinos and stops in a natural Next-to-Minimal Supersymmetric Standard Model (NMSSM) with a singlino as the lightest supersymmetric particle. Motivated by naturalness, we consider spectra with light…
We investigate the constraints to the light neutralino dark matter scenario in the minimal supersymmetric standard model from available experimental observations such as decays of B and K meson, relic dark matter abundance, and the search…
We analyze the scenario within the Next to Minimal Supersymmetric Standard Model (NMSSM), where the lightest supersymmetric particle (LSP) is singlino-like neutralino. By systematically considering various possible admixtures in the…
We study the low scale predictions of supersymmetric standard model extended by $U(1)_{B-L}\times U(1)_{R}$ symmetry, obtained from $SO(10)$ breaking via a left-right supersymmetric model, imposing universal boundary conditions. Two singlet…