Related papers: Gravitinos from Gravitational Collapse
We reanalyze the constraints on light gluinos (m_{\tilde{g}}\leq 5 GeV/c^2) from the hadronic Z decays into four jets. We find that the published OPAL data from the 1991 and 1992 runs exclude a light quasi-stable gluino with mass \lesssim…
Searches were performed for topologies predicted by gauge-mediated Supersymmetry breaking models (GMSB). All possible lifetimes of the next-to-lightest SUSY particle (NLSP), either the lightest neutralino or slepton, decaying into the…
We consider the cosmological and astrophysical constraints on the decay of massive $E_8 \times E_8^\prime$ superstring axions associated with the hidden sector. We find that decay lifetimes greater than 1 s are ruled out by limits from…
An excess of events at a mass of ~ 125 GeV has been reported by both ATLAS and CMS collaborations using 5/fb of data. If this excess of events is confirmed by further searches with more data, it will have extremely important consequences in…
Analysis of the SUSY spectrum in supergravity unified models is given under the naturalness criterion that the universal scalar mass $(m_0)$ and the gluino mass $(m_{\tilde g})$ satisfy the constraint $m_0, m_{\tilde g}$ less than or equal…
In theories with large extra dimensions, constraints from cosmology lead to non-trivial lower bounds on the fundamental scale M_F, corresponding to upper bounds on the radii of the compact extra dimensions. These constraints are especially…
The standard $\Lambda$-CDM predicts a growth of structures which tends to be higher than the values of redshift space distortion (RSD) measurements, if the cosmological parameters are fixed by the CMB data. In this paper we point out that…
A keV-scale gravitino arsing from a minimal supersymmetric (SUSY) Standard Model (MSSM) is an interesting possibility since the small scale problems that $\Lambda$CDM model encounters in the modern cosmology could be alleviated with the…
Partial Split Supersymmetry with bilinear R-parity violation allows to reproduce all neutrino mass and mixing parameters. The viable dark matter candidate in this model is the gravitino. We study the hypothesis that both possibilities are…
We obtain mass limits on the extra neutral gauge boson which is predicted in a model with hidden gauge symmetry and dynamical breaking of the electroweak symmetry by a top quark condensate. For typical model assumptions, present LEP data…
We derive the maximum fraction of energy emitted in the form of massive (Kaluza- Klein) gravitons by core collapse supernovae, and the corresponding minimal extra-dimensional Planck mass M* in the ADD gravity framework at TeV scales. Our…
Explosive astrophysical events at high red shift can be used to place severe limits on the fractional variation in the speed of light ($\Delta c/c$), the photon mass ($m_{\gamma}$), and the energy scale of quantum gravity ($E_{QG}$). I find…
Light gravitinos, with mass in the eV to MeV range, are well-motivated in particle physics, but their status as dark-matter candidates is muddled by early-Universe uncertainties. We investigate how upcoming data from colliders may clarify…
We examine stabilities of our supersymmetry-breaking false vacuum in a low-energy direct gauge mediation model of SUSY breaking. The stability required in the high-temperature early universe leads to upperbounds on masses of squarks and…
In the framework of minimal supersymmetric model we examine the Z-peak constraints on the scenario of one light sbottom (2--5.5 GeV) and light gluino (12--16 GeV), which has been successfully used to explain the excess of bottom quark…
It is generally believed that weak scale supersymmetry implies weak scale supergravity, in the sense that the masses of the gravitino and gravitationally coupled moduli have masses below 100 TeV. This paper presents a realistic framework…
We show that the gravitino contribution to (g-2)_{\mu} is finite in many popular supergravity models, including no-scale supergravity and string and M-theory models. This contribution is greatly enhanced for very light gravitino masses, and…
In recently introduced Split Susy theories, in which the scale of Susy breaking is very high, the requirement that the relic abundance of the Lightest SuperPartner (LSP) provides the Dark Matter of the Universe leads to the prediction of…
Recently, both the ATLAS and CMS experiments have observed an excess of events that could be the first evidence for a 125 GeV Higgs boson. We investigate an implication of the CP-even Higgs boson with mass around 125 GeV in the context of…
We present new upper limits on the light Higgs boson mass mh in supersymmetric models. We consider two gravity-mediated models (with and without universal scalar masses) and two gauge-mediated models (with a 5+5 or 10+10 messenger sector).…