Konstantin T. Matchev

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We analyze focus points in supersymmetric theories, where a param-eter's renormalization group trajectories meet for a family of ultraviolet boundary conditions. We show that in a class of models including minimal supergravity, the up-type Higgs mass has a focus point at the weak scale, where its value is highly insensitive to the universal scalar mass. As(More)
We propose a new set of supersymmetric benchmark scenarios, taking into account the constraints from LEP, b → sγ, g µ − 2 and cosmology. We work in the context of the constrained MSSM (CMSSM) with universal soft supersymetry-breaking masses and assume that R parity is conserved. We propose benchmark points that exemplify the different generic possibilities,(More)
In recent work, it has been argued that multi-TeV masses for scalar su-perpartners are not unnatural. Indeed, they appear to have significant phe-nomenological virtues. Here we explore the implications of such 'focus point' supersymmetry for the dark matter problem. We find that constraints on relic densities do not place upper bounds on neutralino or(More)
We compute the leading QCD corrections to K-K mixing in the supersym-metric standard model with general soft supersymmetry-breaking parameters. We construct the ∆S = 2 effective Lagrangian for three hierarchies of super-symmetric particle masses, namely, when the gluino mass is comparable to, much greater than, or much less than the masses of the first two(More)
We propose that cold dark matter is made of Kaluza-Klein particles and explore avenues for its detection. The lightest Kaluza-Klein state is an excellent dark matter candidate if standard model particles propagate in extra dimensions and Kaluza-Klein parity is conserved. We consider Kaluza-Klein gauge bosons. In sharp contrast to the case of supersymmetric(More)
Universal extra dimensions and supersymmetry have rather similar experimental signatures at hadron colliders. The proper interpretation of an LHC discovery in either case may therefore require further data from a lepton collider. In this paper we identify methods for discriminating between the two scenarios at the linear collider. We study the processes of(More)
The prospects for discovering and studying signals of low-scale supersymmetry breaking models at the Tevatron Run II and beyond are explored. These models include gauge-mediated supersymmetry breaking as the most compelling and concrete realization, but more generally are distinguished by the presence of a nearly massless Goldstino as the lightest(More)
Dark matter candidates arising in models of particle physics incorporating weak scale supersymmetry may produce detectable signals through their annihilation into neutrinos, photons, or positrons. A large number of relevant experiments are planned or underway. The 'logically possible' parameter space is unwieldy. By working in the framework of minimal(More)