Related papers: Supernova Constraints on a Superlight Gravitino
Gauge mediated supersymmetry breaking scenarios with an ultra-light gravitino of mass m_{3/2}=1-10 eV are very interesting, since there is no cosmological gravitino problem. We propose a new experimental determination of the gravitino mass…
We revisit astrophysical constraints on models with an ultra-light gravitino, in particular extending the analysis to more general models and the case of R-parity breaking. These constraints allow to restrict the value of the gravitino mass…
Supersymmetry breakdown via gaugino condensation in heterotic string theory can lead to models with a doubly suppressed gravitino mass. A TeV scale gravitino can emerge from a condensate as large as the grand unified scale. We analyze the…
In theories with a gauge-mediated mechanism of supersymmetry breaking the gravitino is likely to be the lightest superparticle and, hence, a candidate for dark matter. We show that the decay of the next-to-lightest superparticle into a…
Gravitino production and decay in the inflationary universe are reexamined. Assuming that the gravitino mainly decays into a photon and a photino, we calculate the upperbound on the reheating temperature. Compared to previous works, we have…
We show that light ($\simeq$ 1 -- 30 MeV) dark matter particles can play a significant role in core-collapse supernovae, if they have relatively large annihilation and scattering cross sections, as compared to neutrinos. We find that if…
We discuss gravitino production from reheating in models where the splitting between particle and sparticle masses can be larger than TeV, as naturally arising in the context of split supersymmetry. We show that such a production typically…
We study the phenomenology of generic supergravity models in which gravity mediation naturally competes with gauge mediation as the origin of supergravity-breaking. This class of hybrid models has been recently motivated in string inspired…
Supernova cooling provides a powerful probe of physics beyond the Standard Model (SM), in particular for new, light states interacting feebly with SM particles. In this work, we investigate for the first time the production of fermionic…
If the gravitino G is very light and all the other supersymmetric particles are above threshold, supersymmetry may still be found at colliders, by looking at processes with only gravitinos and ordinary particles in the final state. We…
Effects of the unstable gravitino on the big-bang nucleosynthesis (BBN) and its implications to particle cosmology are discussed. If the gravitino mass is smaller than \sim 20 TeV, lifetime of the gravitino becomes longer than \sim 1sec and…
By using a string-inspired modular invariant supergravity, which was proved well to explain WMAP observations appropriately, a mechanism of supersymmetry breaking (SSB) and Gravitino Production just after the end of inflation are…
We show that the constraints on GMSB theories from the gravitino cosmology can be significantly relaxed if the messenger-spurion coupling is temperature dependent. We demonstrate this novel mechanism in a scenario in which this coupling…
I review the constraints on the mass of gravitinos that follow from considerations on energy loss in stars and from Big Bang Nucleosynthesis arguments.
Gravitino production and decay in the inflationary universe are reexanimed. Assuming that gravitino mainly decays into photon and photino, we have calculated the upperbound of the reheating temperature. Compared to previous works, we have…
We show that for gaugino mediated supersymmetry breaking the gravitino mass is bounded from below. For a size of the compact dimensions of order the unification scale and a cutoff given by the higher-dimensional Planck mass, we find…
Recently, Weinberg proposed a scenario where Goldstone bosons may be masquerading as fractional cosmic neutrinos. We calculate the energy loss rates through the emission of these Goldstone bosons in a post-collapse supernova core. Invoking…
We consider, in the context of the minimal supersymmetric standard model, the case where the gravitino weighs 10^6 GeV or more, which is preferred by various cosmological difficulties associated with unstable gravitinos. Despite the large…
An upper limit on the masses of scalar superpartners in split supersymmetry is found by considering cosmological constraints on long-lived gluinos. Over most of parameter space, the most stringent constraint comes from big bang…
We make use of the phase space density approach to discuss gravitino as a warm dark matter candidate. Barring fine tuning between the reheat temperature in the Universe and superparticle masses, we find that \emph{warm} gravitinos have both…