Konstantin T Matchev

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In this paper we compute one-loop corrections to masses and couplings in the minimal supersym-metric standard model. We present explicit formulae for the complete corrections and a set of compact approximations which hold over the unified parameter space associated with radiative electroweak symmetry breaking. We illustrate the importance of the corrections(More)
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)
For a top quark mass fixed to its measured value, we find natural regions of minimal supergravity parameter space where all squarks, sleptons, and heavy Higgs scalars have masses far above 1 TeV and are possibly beyond the reach of the Large Hadron Collider at CERN. This result is simply understood in terms of " focus point " renormalization group behavior(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)
We propose to use the M T 2 concept to measure the masses of all particles in SUSY-like events with two unobservable, identical particles. To this end we generalize the usual notion of M T 2 and define a new M (n,p,c) T 2 variable, which can be applied to various subsystem topologies, as well as the full event topology. We derive analytic formulas for its(More)
We outline a general strategy for measuring spins, couplings and mixing angles in the case of a heavy partner decay chain terminating in an invisible particle. We consider the common example of a heavy scalar or fermion D decaying sequentially to other heavy particles C, B and A by emitting a quark jet j and two leptons ℓ ± n and ℓ ∓ f. We derive analytic(More)