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: Motivated by the recent LHC hints of a Higgs boson around 125 GeV, we assume a SM-like Higgs with the mass 123-127 GeV and study its implication in low energy SUSY by comparing the MSSM and NMSSM. We consider various experimental constraints at 2-sigma le
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 consider the natural supersymmetry scenario in the framework of the R-parity conserving minimal supersymmetric standard model (called natural MSSM) and examine the observability of stop pair production at the LHC. We first scan the parameters of this s
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: The excess of top quark forward-backward asymmetry (AtFBAFBtA^t_{FB}) reported by the Tevatron and the enhancement of the Higgs decay to diphoton observed by the LHC may point to a same origin of new physics. In this note we examined such anomalies in the
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: Motivated by the recent progress of direct search for the productions of stop pair and sbottom pair at the LHC, we examine the constraints of the search results on the stop (t ̃ ) mass in natural SUSY. We first scan the parameter space of natural SUSY in the framework of MSSM, considering the constraints from the Higgs mass, B-physics and electroweak precision measurements. Then in the allowed parameter space we perform a Monte Carlo simulation for stop pair production followed by t ̃ → tχ ̃0 or t ̃ → bχ ̃+ and sbottom pair production followed by ̃b → bχ ̃0 or ̃b → tχ ̃−. 1111 1111 Using the combined results of ATLAS with 20.1 fb−1 from the search of l + jets + E/ T , hadronic tt ̄+E/T and 2b+E/T, we find that a stop lighter than 600 GeV can be excluded at 95% CL in this scenario.
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: In some supersymmetric models like split supersymmetry or models with non-universal gaugino mass, bino (LSP) and winos (NLSP) may have rather small mass splitting in order to provide the correct dark matter relic density through bino/wino co-annihilation. Such a scenario with the compressed bino/wino is difficult to explore at the LHC. In this work we propose to probe this scenario from pp → jχ ̃02χ ̃±1 followed by χ ̃02 → γχ ̃01 and χ ̃±1 → W∗χ ̃01 → l±νχ ̃01 (this method is also applicable to the compressed bino/higgsino scenario). Through a detailed Monte Carlo simulation for both the signal and the backgrounds, we find that for a mass splitting ∆M ∼ 5 − 15 GeV between bino (LSP) and wino (NLSP), the 14 TeV LHC with luminosity of 500fb−1 can probe the wino up to 150 GeV (the sensitivity can reach 5σ for ∆M = 5 GeV and 2σ for ∆M = 15 GeV). We also investigate the dark matter detection sensitivities for this scenario and find that the planned XENON-1T(2017) cannot fully cover the parameter space with wino below 150 GeV allowed by relic density and the LUX limits.
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: Considering the constraints from collider experiments and dark matter detection, we investigate the SUSY effects in the Higgs production channels e(+) e(?) → Zh at an e(+) e(?) collider with a center-of-mass energy above 240 GeV and γγ → h → bb? at a phot
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 explore the explanation of the Fermi Galactic Center excess (GCE) in the next-to-minimal supersymmetric Standard Model. We systematically consider various experimental constraints including the dark matter (DM) relic density, DM direct detection result
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: Recently the ATLAS collaboration reported a 3σ excess in the leptonic-Z + jets + EmissTTmiss_{T}^{miss} channel. This may be interpreted in the Next-to-Minimal Supersymmetric Standard Model (NMSSM) by gluino pair production with the decay chain g~→qq??χ~0
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 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: 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: In the Next-to-Minimal Supersymmetric Standard Model (NMSSM), all singlet-dominated particles including one neutralino, one CP-odd Higgs boson and one CP-even Higgs boson can be simultaneously lighter than about 100 GeV. Consequently, dark matter (DM) in the NMSSM can annihilate into multiple final states to explain the galactic center gamma-ray excess (GCE). In this work we take into account the foreground and background uncertainties for the GCE and investigate these explanations. We carry out a sophisticated scan over the NMSSM parameter space by considering various experi- mental constraints such as the Higgs data, B-physics observables, DM relic density, LUX experiment and the dSphs constraints. Then for each surviving parameter point we per- form a fit to the GCE spectrum by using the correlation matrix that incorporates both the statistical and systematic uncertainties of the measured excess. After examining the properties of the obtained GCE solutions, we conclude that the GCE can be well explained by the pure annihilations χ ̃01χ ̃01 → b ̄b and χ ̃01χ ̃01 → A1Hi with A1 being the lighter singlet- dominated CP-odd Higgs boson and Hi denoting the singlet-dominated CP-even Higgs boson or SM-like Higgs boson, and it can also be explained by the mixed annihilation χ ̃01χ ̃01 → W+W−,A1H1. Among these annihilation channels, χ ̃01χ ̃01 → A1Hi can provide the best interpretation with the corresponding p-value reaching 0.55. We also discuss to what extent the future DM direct detection experiments can explore the GCE solutions and conclude that the XENON-1T experiment is very promising in testing nearly all the solutions.
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: The ATLAS collaboration recently reported a 3σ excess in the leptonic-Z + jets + EmissTTmiss_{T}^{miss} channel. We intend to interpret this excess by squark pair production in the Next-to-Minimal Supersymmetric Standard Model (NMSSM). The decay chain we
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: The evidence of a new scalar particle X from the 750 GeV diphoton excess, and the absence of any other signal of new physics at the LHC so far suggest the existence of new colored scalars, which may be moderately light and thus can induce sizable Xgg and
分类: 物理学 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-27
摘要: In the simplest Higgs-portal scalar dark matter model, the dark matter mass has been restricted to be either near the resonant mass ( mh/2 ) or in a large-mass region by the direct detection at LHC Run 1 and LUX. While the large-mass region below roughly
分类: 物理学 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-27
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 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-27
摘要: We study the excesses of R(D(?))R(D(?))R(D^{(*)}) and muon g?2g?2g-2 in the framework of a two-Higgs-doublet model with top quark flavor-changing neutral-current (FCNC) couplings. Considering the relevant theoretical and experimental constraints, we find
分类: 物理学 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-27
摘要: Motivated by the latest results of the LHC Run-2 and LUX experiments, we examine the status of the constrained minimal supersymmetric standard model (CMSSM) by performing a global fit. We construct a likelihood function including the electroweak precision