38 research outputs found

    Mass of the lightest Higgs Boson in Supersymmetric Left-Right Models

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    We consider the lightest Higgs boson in naturally R-parity conserving supersymmetric left-right models. We obtain an upper bound on the tree level mass of this lightest Higgs boson. This upper bound depends on the SU(2)LSU(2)_L and SU(2)RSU(2)_R gauge couplings, and the vacuum expectation values of bidoublet Higgs fields, which are needed to break SU(2)L×U(1)YSU(2)_L\times U(1)_Y. The upper bound does not depend on either the SU(2)RSU(2)_R breaking scale or the supersymmetry breaking scale. We evaluate the bound numerically by assuming that the theory remains perturbative upto some scale Λ\Lambda. We find that the bound can be considerably larger than in MSSM. The dominant radiative corrections to the upper bound due to top-stop and bottom-sbottom systems are of the same form as in the minimal supersymmetric standard model.Comment: 14 pages including 2 figures, LaTe

    Phenomenology of SUSY-models with spontaneously broken R-parity

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    We review the consequences of spontaneously broken R-parity in present and planned lepton-lepton colliders. In the left-right models the R-parity, R=(−1)3(B−L)+2SR=(-1)^{3(B-L)+2S}, is preserved due to the gauge symmetry, but it must be spontaneously broken in order to the scalar spectrum to be physically consistent. The spontaneous breaking is generated via a non-vanishing VEV of at least one of the sneutrinos, which necessarily means non-conservation of lepton number LL. The R-parity violating couplings are parametrized in terms of mixing angles, whose values depend on model parameters. Combined with the constraints derived from low-energy measurements this yields allowed ranges for various R-parity breaking couplings. The R-parity breaking allows for the processes in which a single chargino or neutralino is produced, subsequently decaying at the interaction point to non-supersymmetric particles.Comment: 6 pages, Latex, talk given in Beyond the Standard Model V in Balholm, Norwa

    Constraining the scales of supersymmetric left-right models

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    We'll review our study of the constraints on the scales in the supersymmetric left-right model (SUSYLR). The conservation of color and electromagnetism in the ground state of the theory implies a relation between right-handed gauge boson mass and soft squark mass. Furthermore, in general for heavy WRW_R, responsible for spontaneous R-parity breaking, is at most of the order MSUSY/hΔRM_{SUSY}/h_{\Delta_R}, where MSUSYM_{SUSY} is supersymmetry breaking scale and hΔRh_{\Delta_R} is the Yukawa coupling in Majorana mass term for right-handed neutrinos

    SO(10) GUTs with gauge mediated supersymmetry breaking

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    We explore the phenomenology of supersymmetric SO(10) grand unified theories with gauge mediated supersymmetry breaking. We show that if SO(10) breaking proceeds through intermediate left-right symmetric gauge groups which are broken at the supersymmetry breaking scale, then perturbative unification allows the existence of only a few consistent models with very similar phenomenological consequences. We list and discuss some distinctive signatures of these theories. The most remarkable feature of the class of theories introduced here is that, unlike in models with simpler symmetry breaking chains, the allowed messenger spectrum is practically unique.Comment: 5 pages, no figures, uses REVTeX (replaced to match the version to be published in PLB: some typos corrected and a reference updated, a minor clarifying modification to the text

    Higgs sector and R-parity breaking couplings in models with broken U(1)_B-L gauge symmetry

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    Four different supersymmetric models based on SU(2)_L X U(1)_R X U(1)_B-L and SU(2)_L X SU(2)_R X U(1)_B-L gauge symmetry groups are studied. U(1)_B-L symmetry is broken spontaneously by a vacuum expectation value (VEV) of a sneutrino field. The right-handed gauge bosons may obtain their mass solely by sneutrino VEV. The physical charged lepton and neutrino are mixtures of gauginos, higgsinos and lepton interaction eigenstates. Explicit formulae for masses and mixings in the physical lepton fields are found. The spontaneous symmetry breaking mechanism fixes the trilinear R-parity breaking couplings. Only some special R-parity breaking trilinear couplings are allowed. There is a potentially large trilinear lepton number breaking coupling - which is unique to left-right models - that is proportional to the SU(2)_R gauge coupling g_R. The couplings are parametrized by few mixing angles, making the spontaneous R-parity breaking a natural ``unification framework'' for R-parity breaking couplings in SUSYLR models.Comment: 19 pages, no figures, uses REVTeX. To be published in PR

    Constraining the SU(2)RSU(2)_R breaking scale in naturally R-parity conserving supersymmetric models

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    We obtain a relation between right-handed gauge boson mass and soft squark mass in naturally R-parity conserving general supersymmetric left-right models. This relation implies that either WR{W_R} is lighter than twice the soft squark mass, or a ratio of vacuum expectation values (VEVs) in the model, denoted by tan⁥α\tan\alpha, is close to its value of unity in the limit of vanishing D-terms. Generally, we find that for heavy WRW_R tan⁥α\tan\alpha is larger than one, and that the right-handed sneutrino VEV, responsible for spontaneous R-parity breaking, is at most of the order MSUSY/hΔRM_{SUSY}/h_{\Delta_R}, where MSUSYM_{SUSY} is supersymmetry breaking scale and hΔRh_{\Delta_R} is the Yukawa coupling in Majorana mass term for right-handed neutrinos. These constraints follow from SU(3)cSU(3)_c and U(1)emU(1)_{em} gauge invariance of the ground state of the theory.Comment: 10 pages, LaTeX, no figures. Version to appear in Phys.Lett.
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