In this master thesis the possible supersymmetric phenomenologies associated with low-mass mSUGRA are investigated. The main characteristics of the supersymmetric mass spectrum are explained and a systematic method is presented to predict phenomenology directly from the mass spectrum. The resulting phenomenologies are compared to the current ATLAS benchmark points. It is found that some phenomenological scenarios are not covered by these benchmark points.
We study the possibility of a light Dark Matter (DM) within a constrained Minimal Supersymmetric Standard Model (cMSSM) framework augmented by a SM singlet-pair sector to account for the non-zero neutrino masses by inverse seesaw mechanism. Working within a 'hybrid' scenario with the MSSM sector fixed at high scale and the singlet neutrino sector at low scale, we find that, contrary to the case of the usual cMSSM where the neutralino DM cannot be very light, we can have a light sneutrino DM with mass below 100 GeV satisfying all the current experimental constraints from cosmology, collider as …
LEP Data and the Stability of the Potential Confront the mSUGRA Model
在最小超引力（mSUGRA）模型中，超对称标量势是稳定的，这一要求对作为公共标量质量$m_0$的函数的普适Gaugino质量$m_{1/2}$施加了一个上限。结合这与实验下限$m_{1/2}$从LEP数据，我们发现一个新的下限$m_0$，强于一个来自实验数据。如果在Tevatron Run II或LHC中发现超粒子质量的相应上限和下限被违反，这将意味着我们生活在一个假真空中。由于重整化尺度的选择，在估计这些预测中的不确定性时特别注意。间接方法（超对称暗物质，g - 2的μ子，$ b \to s γ$.进行了简要讨论。
Supersymmetric parameter constraints from isospin asymmetry in b -> s gamma transitions
由于实验测量值很小，b -> s γ跃迁中的同位旋不对称性对新的物理参数提供了严格的限制。我们在这里利用这个新的可观测研究不同的超对称模型。为了这个目的，我们计算的同位旋对称性破缺MSSM最小味破坏，考虑非线性光学贡献。我们研究了三种超对称破缺的情形，即mSUGRA，AMSB和GMSB。在大多数探索的地区，我们发现这些模型的允许参数非常严格的约束。
I study the phenomenology of heavy neutral bosons Z', predicted in GUT-inspired U(1)' models, at the Large Hadron Collider. In particular, I investigate possible signatures due to Z' decays into superymmetric particles, such as chargino, neutralino and sneutrino pairs, leading to final states with charged leptons and missing energy. The analysis is carried out at sqrt{s}=14 TeV, for a few representative points of the parameter space of the Minimal Supersymmetric Standard Model, suitably modified to accommodate the extra Z' boson and consistent with the discovery of a Higgs-like boson with mass…
This dissertation investigates the flavor mixing effects in supersymmetric models on electroweak precision observables, Higgs boson mass predictions, B-physics observables, quark flavor violating Higgs decays, lepton flavor violating charged lepton decays and lepton flavor violating Higgs decays. The flavor mixing effects are studied in model independent way i.e. by putting off-diagonal entries in the sfermion mass matrix by hand as well as in the minimal flavor violating constrained MSSM, where mixing can originate from CKM matrix in the case of squarks and from PMNS matrix in the case of sle…
The supersymmetric grand unified theory with the Hosotani mechanism predicts the existence of adjoint chiral supermultiplets at the SUSY breaking scale. In particular, the SU(2) triplet and the singlet chiral superfields affect the Higgs sector. We investigate the contributions from these adjoint chiral multiplets to the masses of the Higgs sector particles and their couplings to the standard model particles. We show that the predicted values of the Higgs sector parameters deviate from the standard model and the minimal supersymmetric standard model by O(1)% - O(10)%.
Recent measurements by Planck, LHC experiments, and Xenon100 have significant impact on supersymmetric models and their parameters. We first illustrate the constraints in the mSUGRA plane and then perform a detailed analysis of the general MSSM with 13 free parameters. Using SFitter, Bayesian and Profile Likelihood approaches are applied and their results compared. The allowed structures in the parameter spaces are largely defined by different mechanisms of dark matter annihilation in combination with the light Higgs mass prediction. In mSUGRA the pseudoscalar Higgs funnel and stau co-annihila…
我们在超对称反跷跷板模型的框架下研究中微子的质量。与非超对称的版本不同的是，仅用一对单态的最小实现就足以解释所有的中微子数据。我们计算的中微子质量矩阵的1-循环顺序，并显示如何中微子数据可以描述的模型参数。然后，我们计算率轻子味违反（LFV）的过程，如$μ\to e γ$，和电荷衰变到单重标量中微子。后一种衰变可能在LHC上观测到，并显示出由产生观测到的大中微子角的相同参数决定的特征衰变模式。
We study the 2010 specific version of the 2002 proposed $U(1)_X$ extension of the supersymmetric standard model, which has no $μ$ term and conserves baryon number and lepton number separately and automatically. We consider in detail the scalar sector as well as the extra $Z_X$ gauge boson, and their interactions with the necessary extra color-triplet particles of this model, which behave as leptoquarks. We show how the diphoton excess at 750 GeV, recently observed at the LHC, may be explained within this context. We identify a new fermion dark-matter candidate and discuss its properties. An im…
