Search

A wide variety of unified models predict asymptotic relations at MGUT between the b quark and t lepton Yukawa couplings. Within the framework of supersymmetric SU(4)xSU(2)LxSU(2)R, we explore regions of the parameter space that are compatible with b - t quasi Yukawa Unification, Higgsinos being the lightest supersymmetric particles (≤1TeV) accompanied by a relatively low level of fine-tuning determined by the parameter ΔEW (~200). Among the colored sparticles, the stop weighs more than 1.5 TeV or so, whereas the squarks of the first two families are significantly heavier, approaching 10 TeV in some cases. The gluino mass is estimated to lie in the 2-4 TeV range which raises the important question: Will the LHC find the gluino? [ABSTRACT FROM AUTHOR]

We explore the implications of the t-b-τ (and b-τ) Yukawa coupling unification condition on the fundamental parameter space and sparticle spectroscopy in the minimal gauge mediated supersymmetry breaking model. We find that this scenario prefers values of the CP-odd Higgs mass mA ≳ 1 TeV, with all colored sparticle masses above 3 TeV. These predictions will be hard to test at LHC13 but they may be testable at the high-energy LHC (HE-LHC) 33 TeV or a 100 TeV collider. Both the t-b-τ and the b-τ Yukawa coupling unification prefer a relatively light gravitino with mass ≲30 eV, which makes it a candidate hot dark matter particle. However, it cannot account for more than 15% of the observed dark matter density. [ABSTRACT FROM AUTHOR]

We study a grand unified theories inspired supersymmetric model with nonuniversal gaugino masses that can explain the observed muon g -- 2 anomaly while simultaneously accommodating an enhancement or suppression in the h → γγ decay channel. In order to accommodate these observations and mh ≃ 125 to 126 GeV, the model requires a spectrum consisting of relatively light sleptons whereas the colored sparticles are heavy. The predicted stau mass range corresponding to Rγγ ≥ 1.1 is 100 GeV≲ mτ... ≲ 200 GeV. The constraint on the slepton masses, particularly on the smuons, arising from considerations of muon g -- 2 is somewhat milder. The slepton masses in this case are predicted to lie in the few hundred GeV range. The colored sparticles turn out to be considerably heavier with mḡ ≳ 4.5 TeV and mt1... ≳ 3.5 TeV, which makes it challenging for these to be observed at the 14 TeV LHC. [ABSTRACT FROM AUTHOR]

The discovery of the Higgs boson at the Large Hadron Collider (LHC) has a great impact on the minimal supersymmetric extension of the Standard Model (MSSM). In the context of the constrained MSSM (CMSSM) and its extension with nonuniversal masses for the MSSM Higgs doublets, sparticles with masses > 1 TeV are necessary to reproduce the observed Higgs boson mass of 125-126 GeV. On the other hand, there appears to be a significant amount of discrepancy between the measured muon g - 2 and the Standard Model prediction. A successful explanation of this discrepancy in the MSSM requires new contributions involving relatively light sparticles with masses < 1 TeV. In this paper, we attempt to accommodate the two conflicting requirements in a SU(5) inspired extension of the CMSSM. We assign nonuniversal but flavor blind soft supersymmetry breaking masses to the scalar components in 5 and 10 matter supermultiplets. The two MSSM Higgs doublets in the 5, 5 representations of SU(5) are also assigned unequal soft mass² at MGUT. We identify parameter regions which can simultaneously accommodate the observed Higgs boson mass and the muon g - 2 data, and which are compatible with other phenomenological constraints such as neutralino dark matter relic abundance and rare B-meson decays. Some regions of the allowed parameter space will be explored at the upgraded LHC and by dark matter direct detection experiments. [ABSTRACT FROM AUTHOR]

We examine the low scale particle spectroscopy of an SO(10) [or equivalently SU(5)] inspired supersymmetric model with nonuniversal gaugino masses. The model assumes minimal supergravity and contains the same number of fundamental parameters as the constrained minimal supersymmetric standard model. Realistic solutions compatible with dark matter and other applicable experimental constraints are shown to exist for both positive and negative signs of the minimal supersymmetric standard model parameter μ. We present several benchmark points which will be tested at the LHC and by the ongoing direct and indirect dark matter detection experiments. [ABSTRACT FROM AUTHOR]

We propose a pseudo-Goldstone boson dark matter (pGDM) particle in SO(10) grand unified theory (GUT). Due to its Goldstone nature, this pGDM evades the direct DM detection experiments which, otherwise, severely constrain the parameter space of DM models. In SO(10), the pGDM is embedded as a linear combination of the Standard Model (SM) singlet scalars in 16H and ̅126H representations. We consider two scenarios for the intermediate route of SO(10) symmetry breaking (SB) to the SM: SU(5)×U(1)X and Pati-Salam the SU(4)c×SU(2)L×SU(2)R(4-2-2) gauge groups. The vacuum expectation value of ̅126H, which triggers the breaking of U(1)X and 4-2-2 symmetry in the two scenarios, respectively, determines the pGDM lifetime whose astrophysical lower bound provides one of the most stringent constraints. For the 4-2-2 route to SO(10), the successful SM gauge coupling unification requires the 4-2-2 breaking scale to be O(1011) GeV, and most of the parameter space is excluded. For the SU(5)×U(1)X route, on the other hand, the U(1)X breaking scale can be significantly higher, and a wide range of the parameter space is allowed. Furthermore, the proton lifetime in the SU(5) case is predicted to be 4.53×1034 years, which lies well within the sensitivity reach of the Hyper-Kamiokande experiment. We also examine the constraints on the model parameter space from the Large Hadron Collider and the indirect DM search by Fermi-LAT and MAGIC experiments. [ABSTRACT FROM AUTHOR]

If the lightest dark matter neutralino has a sufficiently large Higgsino component, its spin-independent and spin-dependent cross sections on nucleons can be sizable enough to be detected soon in direct and indirect surveys. We outline in this paper some characteristic features expected of mixed bino-Higgsino dark matter. If the observed relic density is saturated by the bino-Higgsino dark matter, it fixes the amount of allowable bino-Higgsino mixing and provides predictions for other observables which can be tested at the Large Hadron Collider (LHC). We study the correlation between the cross sections and the branching ratio of Bs→μ+μ-. For a mixed bino-Higgsino dark matter, the mass differences of the neutralinos can be less than MZ. This will cause an excess of lepton pairs, above the standard model predictions, from the decays of the two heavier neutralinos. We discuss implications of the dilepton invariant mass distribution, and outline a way to extract the neutralino parameters for testing gaugino mass unification and deducing the relic density from an interplay of astrophysical detection and LHC measurements. [ABSTRACT FROM AUTHOR]