Related papers: Ultra-high energy LSP
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…
We discuss the production of ultra high energy neutrinos coming from the propagation of ultra high energy cosmic rays and in the framework of top-down models for the production of these extremely energetic particles. We show the importance…
We summarize the current status and future prospects for low energy (weak scale) supersymmetry. In particular, we evaluate the capabilities of various $e^+e^-$, $p\bar p$ and $pp$ colliders to discover evidence for supersymmetric particles.…
Searches for pair production of squarks, sleptons, charginos, and neutralinos are performed with the data collected by the ALEPH detector at LEP at centre-of-mass energies from 188.6 to 201.6 GeV. No evidence for any such signals is…
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,…
In this thesis, I describe in great detail the physics of the decay of any Super-Heavy X particle (with masses up to the grand unification scale ~ 10^16 GeV and possibly beyond), and the computer code I developed to model this process -…
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…
It is proposed that the highest energy $\sim 10^{20}$eV cosmic ray primaries are protons, decay products of a long-lived progenitor whose high kinetic energy arises from decay of a distant (cosmological) superheavy particle, G. Such a…
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 study supersymmetric extensions of the Standard Model with small R-parity and lepton number violating couplings which are naturally consistent with primordial nucleosynthesis, thermal leptogenesis and gravitino dark matter. We consider…
We investigate the cosmological gravitino problem in gauge-mediated supersymmetry breaking models, where the gravitino becomes in general the lightest supersymmetric particle (LSP). In order to avoid the overclosure of the stable gravitino,…
We propose an explanation for the recently reported ultra-high-energy neutrino signal at KM3NeT, which shows no clear association with known astrophysical sources. While decaying dark matter in the Galactic Center is a natural candidate,…
We investigate the idea that ultrahigh energy gamma-rays (E>10 TeV) can be produced when charged particles are accelerated by microscopic black holes. We begin by showing that microscopic black holes may exist as remnants of primordial…
The highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from…
The sources and fluxes of superGZK neutrinos, $E>10^{20}$ eV, are discussed. The fluxes of {\em cosmogenic neutrinos}, i.e. those produced by ultra-high energy cosmic rays (UHECR) interacting with CMB photons, are calculated in the models,…
An intriguing possibility for TeV scale physics is the existence of neutral long lived particles (LOLIPs) that subsequently decay into SM states. Such particles are many cases indistinguishable from missing transverse energy (MET) at…
The origin of Ultra--High Energy ($E \gsim 10^{20}$ eV) Cosmic Rays (UHECR) remains mysterious. I discuss ``top--down'' models, where UHECR originate from the decay of very massive, long--lived particles. I summarize the calculation of the…
The results of a search for top squark (stop) pair production in final states with one isolated lepton, jets, and missing transverse momentum are reported. The analysis is performed with proton--proton collision data at $\sqrt{s} = 8$ TeV…
The presence of a Higgsino-like neutralino next-to-lightest sparticle (NLSP) and a keV scale gravitino ($\widetilde{G}$) LSP opens up new decay modes of the NLSP, mainly to a Higgs/$Z$ boson and the LSP. Besides, a keV-scale gravitino as a…
If dark matter neutral LSPs in the galactic halo decay into two body final states containing photons or neutrinos they could be detected even if the decay rates are very small, 10**{-32} per sec. I calculate mass and lifetime bounds from…