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 examine the lepton flavor-changing processes in R -parity violating MSSM. First, we update the constraints on the relevant R -violating couplings by using the latest data on the rare decays ? i → ? j γ . We find that the updated constraints are much st
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: Extensions of the Standard Model often predict new chiral interactions for top quark, which will contribute to top quark spin correlation and polarization in tt?tt?t\bar{t} production at the LHC. In this work, under the constraints from the current Tevatr
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 order to explain the Tevatron anomaly of the top quark forward-backward asymmetry AtFBAFBtA_{FB}^t in the left-right twin Higgs model, we choose to give up the lightest neutral particle of h^h^\hat{h} field as a stable dark matter candidate. Then a new
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 examine the lepton flavor-changing processes in R -parity violating MSSM. First, we update the constraints on the relevant R -violating couplings by using the latest data on the rare decays ? i → ? j γ . We find that the updated constraints are much st
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 the minimal supersymmetric standard model the R-parity violating interactions can trigger various exotic three-body decays for the top quark, which may be accessible at the LHC. In this work we examine the R-violating decays t-> c X_1 X_2, which includ
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 examine various direct and indirect constraints on the lepton-specific two-Higgs doublet model and scrutinize the property of the Higgs bosons in the allowed parameter space. These constraints come from the precision electroweak data, the direct search
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 quark forward-backward asymmetry A_{FB}^{t} measured at the Tevatron is above the Standard Model prediction by more than 2-sigma deviation, which might be a harbinger for new physics. In this work we examine the new physics contribution to A_{FB}^
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 anomaly of the top quark forward-backward asymmetry AtFBAFBtA^t_{FB} observed at the Tevatron can be explained by the t-channel exchange of a neutral gauge boson (Z') which has sizable flavor changing coupling for top and up quarks. This gauge boson c
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 a topcolor-assisted technicolor model (TC2) with large FCNC top quark couplings, we study its correlated contributions to the top quark forward-backward asymmetry (AF B ) at the Tevatron, the top charge asymmetry (AC) and the triple-top production at the LHC. Under current constraints on the top quark from the LHC and Tevatron (such as the total and differential production rates), we scan the parameter space of such a TC2 model. We find that in the allowed parameter space the TC2 model can explain the Tevatron measured AFB at 2σ level, but meanwhile significantly enhance AC at the LHC. Such enhanced AC, albeit currently allowed by the LHC measurement at 2σ level, will serve as a test of TC2 with the improvement of measurement precision at the LHC. Then with all the constraints (including the requirement to explain AF B at 2σ level and satisfying the current LHC measurement of AC at 2σ level), we find that the TC2 model can induce sizable triple-top production at the 14 TeV LHC (the production rate can maximally reach 16 pb). Due to the low SM backgrounds, the triple-top production can also be a good probe for TC2 model, complementary to AC.
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: Inspired by the recent LHC Higgs data and null search results of supersymmetry (SUSY), we scan the parameter space of the Minimal Supersymmetric Standard Model (MSSM) with relatively heavy sparticles (1-3 TeV). Then in the parameter space allowed by curre
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 light of recent remarkable progress in Higgs search at the LHC, we study the rare decay process h→Zγh→Zγh \to Z\gamma and show its correlation with the decay h→γγh→γγh \to \gamma\gamma in low energy SUSY models such as CMSSM, MSSM, NMSSM and nMSSM. Und
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 attempt to explain the recent ATLAS 3σ excess of dilepton events with an invariant mass near Z peak through the gluino-mediated sbottom production in a simplified scenario inspired by the minimal supersymmetric Standard Model. The additional Z bosons c
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: Measuring the Higgs self-coupling is one of the crucial physics goals at the LHC Run-2 and other future colliders. In this work, we attempt to figure out the size of SUSY effects on the trilinear self-coupling of the 125 GeV Higgs boson in the MSSM and NM
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 examine the Higgs triple coupling in MSSM and NMSSM under current constraints, which include the LHC measurements, Higgs data, B physics, electroweak precision observables, relic density and so on. The ratio λMSSMhhh/λSMhhhλhhhMSSM/λhhhSM\lambda^{\rm M
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: Light top squarks (stops) and light higgsinos are the key features of natural supersymmetry (SUSY), where the higgsinos χ?1± and χ?1,20 are nearly degenerate and act as the missing transverse energy (ET) at the LHC. Besides the pair production via strong
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 the minimal supersymmetric model the R-parity violating top quark interactions, which are so far weakly constrained, can induce various flavor-changing neutral-current (FCNC) productions for the top quark at the Large Hadron Collider (LHC). In this wor
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 the minimal supersymmetric standard model the R-parity violating interactions can trigger various exotic three-body decays for the top quark, which may be accessible at the LHC. In this work we examine the R-violating decays t-> c X_1 X_2, which includ
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 examine various direct and indirect constraints on the lepton-specific two-Higgs doublet model and scrutinize the property of the Higgs bosons in the allowed parameter space. These constraints come from the precision electroweak data, the direct search
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: As a top quark factory, the LHC can test the new physics models used to explain the top quark forward-backward asymmetry A^t_FB measured at the Tevatron. In this work we perform a comparative study for two such models: the W'-model and the color triplet d