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Showing papers by "Kai Puolamäki published in 1999"


Journal ArticleDOI
TL;DR: In this article, the phenomenological aspects of supersymmetric SU(5) grand unified theories with nonuniversal gaugino masses are studied, and the nature of the lightest supersymmymmetric particle is determined.
Abstract: We study the phenomenological aspects of supersymmetric SU(5) grand unified theories with nonuniversal gaugino masses. For large $\mathrm{tan}\ensuremath{\beta},$ we investigate constraints from the requirement of successful electroweak symmetry breaking, the positivity of stau mass squared, and the $\stackrel{\ensuremath{\rightarrow}}{b}s\ensuremath{\gamma}$ decay rate. In the allowed region, the nature of the lightest supersymmetric particle is determined. Examples of mass spectra are given. We also calculate loop corrections to the bottom mass due to superpartners.

52 citations


Journal ArticleDOI
TL;DR: In this article, the authors considered non-universal corrections to the gauge couplings due to higher dimensional operators in supersymmetric SU (5) grand unified theories, which are parametrized by three components originating from 24, 75 and 200 representations.

18 citations


Journal ArticleDOI
TL;DR: In this article, the authors explore the phenomenology of supersymmetric SO(10) grand unified theories with gauge mediated supersymmetry breaking and show that if SO (10) breaking proceeds through intermediate left-right symmetric gauge groups which are broken at the supersymmeter breaking scale, then perturbative unification allows the existence of only a few consistent models with very similar phenomenological consequences.

7 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigate a large class of supersymmetric SO(10) grand unified theories (GUT{close_quote}s) within the framework of gauge-mediated supersymmetry breaking and find that the conditions of the perturbativity of the gauge couplings and unification at the GUT scale severely restrict the messenger sector and lead to testable phenomenological predictions for the sparticle masses.
Abstract: We investigate a large class of supersymmetric SO(10) grand unified theories (GUT{close_quote}s) within the framework of gauge-mediated supersymmetry breaking. We start with the most general messenger sector and embed the standard model gauge group into either SU(2){sub L}{times}SU(2){sub R}{times}U(1){sub B{minus}L} or SU(2){sub L}{times}U(1){sub I{sub 3R}}{times}U(1){sub B{minus}L}. We find that the conditions of the perturbativity of the gauge couplings and unification at the GUT scale severely restrict the messenger sector and lead to testable phenomenological predictions for the sparticle masses. One of the most notable features of the class of supersymmetric SO(10) grand unified theories introduced here is that among the many possible cases there are only a few consistent models, all of which share an essentially unique mass spectrum. {copyright} {ital 1999} {ital The American Physical Society}

7 citations


Journal ArticleDOI
TL;DR: In this article, the authors studied the production of neutralinos and charginos at LEP and at a linear collider in the case of spontaneously broken R-parity, where spontaneous R parity breaking is inevitable and is associated with the breaking of the LR-symmetry.
Abstract: We study the production of neutralinos and charginos at LEP and at a linear collider in the case of spontaneously broken R-parity. We first investigate the constraints on the single neutralino and chargino production from the LEP 1 experiments, and then we consider the production at LEP 2 and at a linear collider. We concentrate on the supersymmetric $SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ model, where the spontaneous R-parity breaking is inevitable and is associated with the breaking of the LR-symmetry.

5 citations


Journal ArticleDOI
TL;DR: In this article, a nonzero product of two λ′-type couplings and working in two different bases for the left-handed quark superfields are used to bound these products.

5 citations


Posted Content
TL;DR: In this article, the phenomenology of light Higgs scalars in supersymmetric left-right models was studied and the upper bound on the lightest CP-even neutral Higgs boson in these models was larger than in the minimal supersymmymmetric standard model and the Higgs couplings to fermions approach those of the Standard Model.
Abstract: We review the phenomenology of light Higgs scalars in supersymmetric left-right models. We consider models with minimal particle content (with and without non-renormalizable higher-dimensional terms) and with additional Higgs superfields. The upper bound on the lightest CP-even neutral Higgs boson in these models is larger than in the minimal supersymmetric standard model, and the Higgs couplings to fermions approach those of the Standard Model. Possibly light doubly charged Higgs boson may provide the best signature of these models.

4 citations


Journal ArticleDOI
TL;DR: In this paper, the authors studied a class of generalized models of gauge mediated supersymmetry breaking (GMSB) and found the parameters and the full particle spectrum of the minimal supersymmetric standard model for all GMSB models with messenger multiplicities that satisfy the perturbativity of the gauge couplings up to the GUT scale.

3 citations


Posted Content
TL;DR: In this paper, the mass of the light CP-even neutral Higgs boson in supersymmetric left-right models (SLRM) has been analyzed, including models with minimal particle content and those with additional Higgs superfields.
Abstract: We carry out a detailed analysis of the light Higgs bosons in supersymmetric left-right models (SLRM). This includes models with minimal particle content and those with additional Higgs superfields. We also consider models with non-renormalizable higher-dimensional terms. We obtain an upper bound on the mass of the lightest CP-even neutral Higgs boson in these models. The upper bound depends only on the gauge couplings, and the vacuum expectation values of those neutral Higgs fields which control the spontaneous breakdown of the SU(2) L * U(1) Y gauge symmetry. We calculate the one-loop radiative corrections to this upper bound, and evaluate it numerically in the minimal version of the supersymmetric left-right model. We consider the couplings of this lightest CP-even Higgs boson to the fermions, and show that in a phenomenologically viable model the branching ratios are similar to the corresponding branching ratios in the minimal supersymmetric standard model (MSSM). We then study the most promising particle for distinguishing the SLRM from other models, namely the doubly charged Higgs boson. We obtain the mass of this doubly charged Higgs boson in different types of supersymmetric left-right models, and discuss its phenomenology.

3 citations


Posted Content
TL;DR: The left-right model is a gauge theory of electroweak interactions based on the gauge symmetry SU(2) R. The main motivations for this model are that it gives an explanation for the parity violation of weak interactions, provides a mechanism (see-saw) for generating neutrino masses, and has B-L as a gauge symmetry as mentioned in this paper.
Abstract: The left-right model is a gauge theory of electroweak interactions based on the gauge symmetry SU(2) R . The main motivations for this model are that it gives an explanation for the parity violation of weak interactions, provides a mechanism (see-saw) for generating neutrino masses, and has B-L as a gauge symmetry. The quark-lepton symmetry in weak interactions is also maintained in this theory. The model has many predictions one can directly test at a TeV-scale linear collider. We will consider here two processes (e,e→ q, q, barQ, barQ and e,e ->μ , ν , q, barQ) testing the lepton flavour violation predicted by the model. We will also discuss constraints on supersymmetric versions of the model.

2 citations


Journal ArticleDOI
TL;DR: In this paper, the authors consider non-universal corrections to the gauge couplings due to higher dimensional operators in supersymmetric SU(5) grand unified theories and consider the prediction of $\alpha_3(M_Z)$ along each {\bf 24, {\bf 75} and {\bf 200} direction.
Abstract: We study non-universal corrections to the gauge couplings due to higher dimensional operators in supersymmetric SU(5) grand unified theories. The corrections are, in general, parametrized by three components originating from {\bf 24}, {\bf 75} and {\bf 200} representations. We consider the prediction of $\alpha_3(M_Z)$ along each {\bf 24}, {\bf 75} and {\bf 200} direction, and their linear combinations. The magnitude of GUT scale and its effects on proton decay are discussed. Non-SUSY case is also examined.