分类: 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 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 funct
分类: 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
分类: 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 a realistic 5D orbifold GUT model that can reduce to natural (or radiative natural) supersymmetry as the low energy effective theory. Supersymmetry as well as gauge symmetry are broken by the twist boundary conditions. We find that it is non-trivial to introduce other flavor symmetry other than the SU(2)R R-symmetry. We ameliorate the tension between the small number of free parameters and the successful electroweak symmetry breaking by introducing non-minimal Kahler potentials. A large trilinear term At, which is necessary to give a 125 GeV Higgs boson, is naturally provided in our scenario. A scan under current experimental constraints shows that our model can realize natural (or radiative natural) supersymmetry. Only radiative natural supersym- metry can naturally lead to 125 GeV higgs. Additional dark matter species other than neutralino(like axion) are needed to provide enough relic density. Relatively large stop masses are necessary to give realistic higg mass in most of the parameter spaces.
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要:We recalculate the two-loop beta functions for three gauge couplings taking into account all low energy threshold corrections in split supersymmetry (split-SUSY) which assumes a very high scalar mass scale MSMSM_S . We find that in split-SUSY with a gaugi
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要:In this work we show that the general singlet extension of the minimal supersymmetric standard model (MSSM) can naturally provide a self-interacting singlino dark matter to solve the small cosmological scale anomalies (a large Sommerfeld enhancement facto
分类: 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 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) GU
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
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 ob
分类: 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 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 gμ − 2 experiment and LHC data can be reconciled in this scenario. We also find that the parameter space for explaining the gμ − 2 anomaly at 1σ level can be fully covered by the future LUX-ZEPLIN 7.2 Ton experiment.
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要:The top and bottom seesaw model, which extends the top seesaw in order to accommodate a 125 GeV Higgs boson, predicts vector-like top/bottom partners and these partners can be bounded to form several neutral and charged singlet composite scalars by some n
分类: 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 to interpret the 750 GeV diphoton excess in deflected anomaly mediation supersymmetry breaking scenarios, which can naturally predict couplings be- tween a singlet field and vector-like messengers. The CP-even scalar component (S) of the singlet field can serve as the 750 GeV resonance. The messenger scale, which is of order the gravitino scale, can be as light as Fφ ∼ O(10) TeV when the messenger species NF and the deflection parameter d are moderately large. Such messengers can induce the large loop decay process S → γγ. Our results show that such a scenario can successfully accommo- date the 125 GeV Higgs boson, the 750 GeV diphoton excess and the muon g − 2 without conflicting with the LHC constraints. We also comment on the possible explanations in the gauge mediation supersymmetry breaking scenario.
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要:In split supersymmetry the gauginos and higgsinos are the only supersymmetric particles possibly accessible at foreseeable colliders like the CERN Large Hadron Collider (LHC) and the International Linear Collider (ILC). In order to account for the cosmic
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要:To understand the origin of the left–right symmetry, we study a partial unification model based on SU ( 4 ) W × U ( 1 ) B ? L which can be broken down to the minimal left–right model either through the Higgs mechanism in four dimensions or through the fiv
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要:We embed the minimal left-right model SU(2)_L\times SU(2)_R\times U(1)_{B-L} into an SU(4)_W gauge group, and break the unified group via five-dimensional S^1/(Z_2\times Z_2) orbifolding. Leptons are fitted into SU(4)_W multiplets and located on a symmetr
分类: 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 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 funct
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-27
摘要:In this work, we explain the 750 GeV diphoton resonance in the Next to Minimal Supersymmetric Standard Model (NMSSM) by introducing vector-like particles. Such an extension is well motivated from the top-down view since some grand unified theories usually
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-27
摘要:A radiative natural SUSY spectrum are proposed in the deflected anomaly mediation scenario with general messenger-matter interactions. Due to the contributions from the new interactions, positive slepton masses as well as a large |Att_{t} | term can natur
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-15
摘要:We split the two-Higgs-doublet model by assuming very different vevs for the two doublets: the vev is at weak scale (174 GeV) for the doublet Phi(1) and at neutrino-mass scale (10(-2) - 10(-3) eV) for the doublet Phi(2). Phi(1) is responsible for giving masses to all fermions except neutrinos; while Phi(2) is responsible for giving neutrino masses through its tiny vev without introducing the see-saw mechanism. Among the predicted five physical scalars H, h, A(0) and H-+/-, the CP-even scalar h is as light as 10(-2) - 10(-3) eV while the others are at weak scale. We identify h as the cosmic-dark-energy field and the other CP-even scalar H as the Standard Model Higgs boson; while the CP-odd A(0) and the charged H-+/- are the exotic scalars to be discovered at future colliders. Also we demonstrate a possible dynamical origin for the doublet Phi(2) from neutrino condensation caused by some unknown dynamics.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-15
摘要:In split supersymmetry, gauginos and Higgsinos are the only supersymmetric particles that are potentially accessible at soon-to-be-completed colliders. While direct experimental research, such as the LEP and Tevatron experiments, have given robust lower bounds on the masses of these particles, cosmic dark matter can give some upper bounds and thus have important implications for research at future colliders. In this work we scrutinize such dark matter constraints and show the allowed mass range for charginos and neutralinos (the mass eigenstates of gauginos and Higgsinos). We find that the lightest chargino must be lighter than about 1 TeV under the popular assumption M-1 = M-2/2 and about 2 or 3 TeV in other cases. The corresponding production rates of the lightest chargino at the CERN large hadron collider (LHC) and the International Linear Collider (ILC) are also given. While in some parts of the allowed region the chargino pair production rate can be larger than 1 pb at the LHC and 100 fb at the ILC, other parts of the region correspond to very small production rates, and thus there is no guarantee of finding the charginos of split supersymmetry at future colliders.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-15
摘要:In split-supersymmetry (split-SUSY), gluino is a metastable particle and thus can freeze out in the early universe. The late decay of such a long-life gluino into the lightest supersymmetric particle (LSP) may provide much of the cosmic dark-matter content. In this work, assuming the LSP is gravitino produced from the late decay of the metastable gluino, we examine the Wilkinson microwave anisotropy probe (WMAP) dark-matter constraints on the gluino mass. We find that to provide the full abundance of dark matter, the gluino must be heavier than about 14 TeV and thus not accessible at the CERN large hadron collider (LHC).
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-15
摘要:In the Affleck-Dine mechanism of baryogenesis, nontopological solitons called Q-balls can be formed. In this work we propose that such Q-balls decay during the BBN era and study the cosmological consequence of such late decays. We find that the late-decaying baryonic Q-balls with lifetime of about 10(3) s can provide a new developing mechanism for the BBN through a rolling baryon-to-photon ratio eta, which can naturally explain the discrepancy of the BBN prediction with the WMAP data on Li-7 abundance. For the late-decaying leptonic Q-balls with lifetime of about 10(6) s, we find that their decay product, gravitinos, can serve as a dark matter candidate and give an explanation for the approximate equality of dark and baryon matter densities. (C) 2004 Elsevier B.V. All rights reserved.