分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-15
摘要: We propose a realistic flipped SU(5) model derived from a five-dimensional orbifold SO(10) model. The Standard Model (SM) fermion masses and mixings are explained by combining the traditional Froggatt-Nielsen mechanism with the five-dimensional wave function profiles of the SM fermions. Employing tree-level spontaneous R-symmetry breaking in the hidden sector and extra( ordinary) gauge mediation, we obtain realistic supersymmetry breaking soft mass terms with non-vanishing gaugino masses. Including the messenger fields at the intermediate scale and Kaluza-Klein states at the compactification scale, we study gauge coupling unification. We show that the SO(10) unified gauge coupling is very strong and the unification scale can be much higher than the compactification scale. We briefly discuss proton decay as well.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-14
摘要: To obtain a standard model-like Higgs boson around 125 GeV in the minimal supersymmetric standard model with minimal gauge mediation of supersymmetry breaking (GMSB), a heavy stop at multi-TeV level is needed and incurs severe fine-tuning, which can be ameliorated in the framework of the deformed GMSB with visible-hidden direct Yukawa interactions (YGMSB). We examine some general features of the YGMSB and focus on the scenario with Higgs-messenger couplings (HYGMSB) which can automatically maintain the minimal flavor violation. It turns out that such a Yukawa mediation scenario can give a large -Lambda(t) and -m((t) over tildeL,R)(2), leading to a maximal stop mixing, and thus can readily give a light stop ((t) over tilde (1)) below the TeV scale. However, we find that in the minimal HYGMSB scenario, m(Hu)(2) is too large and then the electroweak symmetry breaking is inconsistent with the large stop mixing. To solve this problem, we modify the hidden sectors in two ways, adding a new strong gauge dynamics or introducing the (10, (10) over bar) messengers. For each case we present some numerical studies.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-07-26
摘要: Kibble mechanism drastically underestimates the production of point-like topological defects, as confirmed recently in atomic and condensed matter systems If non-thermally produced, they can be cosmological dark matter of mass 1-10 PeV or heavier If thermalized, skyrimon of mass 1-10 TeV is also a viable dark matter candidate, whose decay may explain e(+/-) spectra in cosmic rays recently measured by PAMELA, FERMI, and HESS Collaborations Models that produce magnetic monopoles below the inflation scale, such as Pati-Salam unification, are ruled out unless new annihilation mechanism for monopoles is introduced (C) 2010 Elsevier B V All rights reserved
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-09
摘要: We propose a deflected anomaly mediation scenario from SUSY QCD which can lead to both positive and negative deflection parameters (there is a smooth transition between these two deflection parameter regions by adjusting certain couplings). Such a scenario can naturally give a SUSY spectrum in which all the colored sparticles are heavy while the sleptons are light. As a result, the discrepancy between the Brookheaven g(mu) - 2 experiment and LHC data can be reconciled in this scenario. We also find that the parameter space for explaining the g(mu) - 2 anomaly at 1 sigma level can be fully covered by the future LUX-ZEPLIN 7.2 Ton experiment.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-09
摘要: From generalized gravity mediation we build a SUGRA scenario in which the gluino is much heavier than the electroweak gauginos at the GUT scale. We find that such a non-universal gaugino scenario with very heavy gluino at the GUT scale can be naturally obtained with proper high dimensional operators in the framework of SU( 5) GUT. Then, due to the effects of heavy gluino, at the weak scale all colored sparticles are heavy while the uncolored sparticles are light, which can explain the Brookhaven muon g - 2 measurement while satisfying the collider constraints (both the 125 GeV Higgs mass and the direct search limits of sparticles) and dark matter requirements. We also find that, in order to explain the muon g - 2 measurement, the neutralino dark matter is lighter than 200GeV in our scenario, which can be mostly covered by the future Xenon1T experiment.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-09
摘要: We propose to split the sparticle spectrum from the hierarchy between the GUT scale and the Planck scale. A split supersymmetric model, which gives non-universal gaugino masses, is built with proper high dimensional operators in the framework of SO(10) GUT. Based on a calculation of two-loop beta functions for gauge couplings (taking into account all weak scale threshold corrections), we check the gauge coupling unification and dark matter constraints (relic density and direct detections). We find that our scenario can achieve the gauge coupling unification and satisfy the dark matter constraints in some part of parameter space. We also examine the sensitivity of the future XENON1T experiment and find that the currently allowed parameter space in our scenario can be covered for a neutralino dark matter below about 1.0 TeV.
分类: 物理学 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: We propose the SUSY SU(7) unification of the SU(3)_C* SU(4)_W* U(1)_{B-L} model. Such unification scenario has rich symmetry breaking chains in a five-dimensional orbifold. We study in detail the SUSY SU(7) symmetry breaking into SU(3)_C* SU(4)_W* U(1)_{B