Related papers: Solving the Gravitino Problem by Axino
We compute the cosmic relic (dark matter) density of the lightest supersymmetric particle (LSP) in the framework of minimal $N=1$ Supergravity models with radiative breaking of the electroweak gauge symmetry. To this end, we re--calculate…
In the minimal supersymmetric standard model (MSSM) the lightest superparticle (LSP) can be a TeV neutralino (mainly dominated by higgsino or wino) which serves as a dark matter candidate with correct thermal relic density. In this work we…
The search for supersymmetry at Run 1 of LHC has resulted in gluino mass limits m(gluino)>~ 1.3 TeV for the case where m(gluino)<<m(squark) and in models with gaugino mass unification. The increased energy and ultimately luminosity of LHC13…
The large value of the tensor-to-scalar ratio in the cosmic microwave background radiation reported by the BICEP2 collaboration gives strong impact on models of supersymmetry (SUSY). The large ratio indicates inflation with a high-energy…
A wide variety of unified models predict asymptotic relations at $M_{GUT}$ between the b quark and $\tau$ lepton Yukawa couplings. Within the framework of supersymmetric SU(4) $\times$ SU(2)$_L \times$ SU(2)$_R$, we explore regions of the…
We investigate the detectability of axino-like particle, which is defined as a supersymmetric partner of axion-like particle and can be a good candidate for dark matter in our Universe. Especially, we consider the fixed target experiments…
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…
In models of low-energy gauge mediation, the observed Higgs mass is in tension with the cosmological limit on the gravitino mass $m_{3/2} \lesssim 16$ eV. We present an alternative mediation mechanism of supersymmetry breaking via a $U(1)$…
Supergravity embedding of the Standard Model of particle physics provides phenomenologically well-motivated and observationally viable inflationary scenarios. We investigate a class of inflationary models based on the superconformal…
We consider $\mu$-term hybrid inflation which, in its minimal format with gravity mediated supersymmetry breaking, leads to split supersymmetry. The MSSM $\mu$-term in this framework is larger than the gravitino mass $m_G$, and successful…
A new modified string-inspired modular invariant supergravity model is proposed and is applied to realize the slow roll inflation in Einstein frame, so that the model explains WMAP observations very well. Gravitino mass and their production…
We show how successful supersymmetric hybrid inflation is realized in realistic models where the resolution of the minimal supersymmetric standard model mu problem is intimately linked with axion physics. The scalar fields that accompany…
We propose the lightest supersymmetric particle (LSP) as a well-suited candidate for superheavy dark matter (SHDM). Various production mechanisms at the end of inflation can produce SHDM with the correct abundance, $\Omega_{LSP} h^2 \sim…
We investigated the viability of neutralino dark matter in the gauge mediation from emergent supersymmetry proposal. In this proposal, supersymmetry is broken at Planck scale and consequently, the gravitino is superheavy and completely…
Gaugino mediation is an attractive supersymmetry breaking scheme naturally avoiding flavor problems by suppressing the soft sfermion masses at a high-energy scale. We consider an extension of the original model which yields non-vanishing…
A search for gauge-mediated supersymmetry (SUSY) in final states with photons and large missing transverse momentum is presented. The data sample of pp collisions at $\sqrt{s} = $ 13 TeV was collected with the CMS detector at the CERN LHC…
In general the gravitino mass and/or the soft supersymmetry breaking masses in the observable sector can be much larger than the TeV scale. Depending on the relation between the masses, new important channels for gravitino production in the…
Grand-unified models with extra dimensions at the GUT scale will typically contain exotic states with Standard Model charges and GUT-scale masses. They can act as messengers for gauge-mediated supersymmetry breaking. If the number of…
We consider the thermal production of axino dark matter in high-scale supersymmetry where all the superpartners except the axino are heavier than the maximum and reheating temperatures. In this case, the axinos are produced dominantly in…
In the post-LHC8 era, it is perceived that what is left of SUSY model parameter space is highly finetuned in the EW sector (EWFT). We discuss how conventional measures overestimate EWFT in SUSY theory. Radiatively-driven natural SUSY (RNS)…