Article

Pure gravity mediation with m3/2=10-100TeV

(Impact Factor: 4.86). 05/2012; 85(9):95011-. DOI: 10.1103/PhysRevD.85.095011
Source: arXiv

ABSTRACT Recently, the ATLAS and CMS collaborations reported exciting hints of a
standard model-like Higgs boson with a mass around 125 GeV. Such a Higgs
boson mass can be easily obtained in the minimal supersymmetric standard
model based on the “pure gravity mediation model” where the
sfermion masses and the Higgs mass parameters are in the tens to
hundreds TeV range, while the gauginos are in the hundreds GeV to TeV
range. In this paper, we discuss details of the gaugino mass spectrum in
the pure gravity mediation model. We also discuss the signals of the
model at current and future experiments such as cosmic-ray observations
and the LHC experiments. In particular, we show that the parameter space
which is consistent with the thermal leptogenesis can be fully surveyed
experimentally in the foreseeable future.

0 Followers
·
69 Views
• Source
Article: A keV String Axion from High Scale Supersymmetry
[Hide abstract]
ABSTRACT: Various theoretical and experimental considerations motivate models with high scale supersymmetry breaking. While such models may be difficult to test in colliders, we propose looking for signatures at much lower energies. We show that the recent observation of a 3.5 keV line in the X-ray spectrum of galaxy clusters can have its origin in a string axion coupled to a hidden supersymmetry breaking sector. A linear combination of the string axion and an additional axion in the hidden sector remains light, obtaining a mass of order 10 keV through supersymmetry breaking dynamics. In order to explain the X-ray line, the scale of supersymmetry breaking must be about $10^{11-12}$ GeV. This motivates high scale supersymmetry as in pure gravity mediation or minimal split supersymmetry and is consistent with all current limits. Since the axion mass is controlled by a dynamical mass scale, this mass can be much higher during inflation, avoiding isocurvature (and domain wall) problems associated with high scale inflation. In an appendix we present a mechanism for dilaton stabilization that additionally leads to $\mathcal{O}(1)$ modifications of the gaugino mass from anomaly mediation.
Physical Review D 08/2014; 91(4). DOI:10.1103/PhysRevD.91.045036 · 4.86 Impact Factor
• Source
Article: Light Higgsinos in Pure Gravity Mediation
[Hide abstract]
ABSTRACT: Pure gravity mediation (PGM), with two free parameters, is a minimalistic approach to supergravity models, yet is capable of incorporating radiative electroweak symmetry breaking, a Higgs mass in agreement with the experimental measurement, without violating any phenomenological constraints. The model may also contain a viable dark matter candidate in the form of a wino. Here, we extend the minimal model by allowing the $\mu$-term to be a free parameter (equivalent to allowing the two Higgs soft masses, $m_1$ and $m_2$, to differ from other scalar masses) which are set by the gravitino mass. In particular, we examine the region of parameter space where $\mu \ll m_{3/2}$ in which case, the Higgsino becomes the lightest supersymmetric particle (LSP) and a dark matter candidate. We also consider a generalization of PGM which incorporates a Peccei-Quinn symmetry which determines the $\mu$-term dynamically. In this case, we show that the dark matter may either be in the form of an axion and/or a neutralino, and that the LSP may be either a wino, bino, or Higgsino.
Physical Review D 12/2014; 91(5). DOI:10.1103/PhysRevD.91.055008 · 4.86 Impact Factor
• Source
Article: Confronting the Moduli-Induced LSP Problem
[Hide abstract]
ABSTRACT: Moduli fields with Planck-suppressed couplings to light species are common in string compactifications. Decays of these moduli can reheat the universe at a late time and produce dark matter non-thermally. For generic moduli fields motivated by string theory with masses similar to that of the gravitino and TeV-scale superpartners in the minimal supersymmetric Standard Model (MSSM), the non-thermal production of the lightest superpartner (LSP) tends to create an unacceptably large relic density or too strong of an indirect detection signal. We call this the moduli-induced LSP problem of the MSSM. In this paper we investigate extensions of the MSSM containing new LSP candidates that can alleviate this tension. We examine the viability of this scenario in models with light Abelian and non-Abelian hidden sectors, and symmetric or asymmetric dark matter. In these extensions it is possible, though somewhat challenging, to avoid a moduli-induced LSP problem. In all but the asymmetric scenario, the LSP can account for only a small fraction of the observed dark matter density.