Supersymmetric dark matter candidates

Abstract

CERN-PH-TH/2010-004, UMN-TH-2831/10, FTPI-MINN-10/02After reviewing the theoretical, phenomenological and experimental motivations for supersymmetric extensions of the Standard Model, we recall that supersymmetric relics from the Big Bang are expected in models that conserve R parity. We then discuss possible supersymmetric dark matter candidates, focusing on the lightest neutralino and the gravitino. In the latter case, the next-to-lightest supersymmetric particle is expected to be long-lived, and possible candidates include spartners of the tau lepton, top quark and neutrino. We then discuss the roles of the renormalization-group equations and electroweak symmetry breaking in delimiting the supersymmetric parameter space. We discuss in particular the constrained minimal extension of the Standard Model (CMSSM), in which the supersymmetry-breaking parameters are assumed to be universal at the grand unification scale, presenting predictions from a frequentist analysis of its parameter space. We also discuss astrophysical and cosmological constraints on gravitino dark matter models, as well as the parameter space of minimal supergravity (mSUGRA) models in which there are extra relations between the trilinear and bilinear supersymmetry-breaking parameters, and between the gravitino and scalar masses. Finally, we discuss models with non-universal supersymmetry-breaking contributions to Higgs masses, and models in which the supersymmetry-breaking parameters are universal at some scale below that of grand unification. From 'Particle Dark Matter: Observations, Models and Searches' edited byGianfranco Bertone

Testing the Nambu-Goldstone hypothesis for quarks and leptons at the LHC

“…Finally, we note that at small m 0 a gaugino soft mass m 1/2 300 has some phenomenological support, as it givesχ 0 1,2 andχ ± 1,2 masses favored by muon g − 2 [35]. Also, although a small m 0 usually gives dangerously smallτ masses [35], this is not the case if it JHEP01(2011)131 is only for the first and second generations.…”

“…Also, although a small m 0 usually gives dangerously smallτ masses [35], this is not the case if it JHEP01(2011)131 is only for the first and second generations. This accounts for the difference between the gray regions of figures 1 and 2.…”

The moment of truth for WIMP dark matter

“…within the reach of the LHC (see e.g. 54 ). As reasonable and aesthetically appealing as it is, this is not a rigorous mathematical argument, and the actual scale of new physics could be in principle even higher, depending on the amount of fine-tuning one is willing to tolerate.…”

“…Not only it solves in a natural way the hierarchy problem, but it also provides a perfect Dark Matter candidate (more than one, in fact 54 ). There are large portions of the Supersymmetric parameter space within the reach of the LHC, and there are good chances to discover it at the LHC within 5-10 years 55 .…”

Strangeness of the nucleon from lattice QCD

“…Even if in these processes a dark matter particle would not be detected directly, such experiments allow us to provide bounds on the nucleon dark matter cross section which can in turn be translated into constraints on models of new physics. In many supersymmetric scenarios [7] and in some Kaluza-Klein extensions of the standard model [8,9] the dark matter nucleon interaction is mediated through a Higgs boson. In such a case the theoretical expression of the spin independent scattering amplitude at zero momentum transfer involves the y N parameter.…”