We investigate the constraints on Supersymmetry arising from available precision measurements using a global fit approach. When interpreted within minimal supergravity (mSUGRA), the data provide significant constraints on the masses of supersymmetric particles, which are predicted to be light enough for an early discovery at the Large Hadron Collider (LHC). We provide predicted mass spectra including, for the first time, full uncertainty bands. The most stringent constraint is from the measurement of the anomalous magnetic moment of the muon. Using the results of these fits, we investigate to which precision mSUGRA and more general MSSM parameters can be measured by the LHC experiments with three different integrated luminosities for a parameter point which approximately lies in the region preferred by current data. The impact of the already available measurements on these precisions, when combined with LHC data, is also studied. We develop a method to treat ambiguities arising from different interpretations of the data within one model and provide a way to differentiate between values of different digital parameters of a model. Finally, we show how measurements at a linear collider with up to 1 TeV centre-of-mass energy will help to improve precision by an order of magnitude.
We investigate the discovery potential of a Stealth SUSY scenario involving squark decays by reconstructing the lightest neutralino decay products using a large-radius jet containing a high transverse momentum photon. Requirements on the event topology, such as photon and large-radius jet multiplicity result in less background than signal. We also estimated the sensitivity of our analysis and found that it has a better exclusion potential compared to the strongest existing search for the specific benchmark points considered here.
Different approaches are used for the calculation of the SM-like Higgs boson mass in the MSSM: the fixed-order diagrammatic approach is accurate for low SUSY scales; the EFT approach,for high SUSY scales. Hybrid approaches, combining fixed-order and EFT calculations, allow to obtain a precise prediction also for intermediary SUSY scales. Here, we briefly discuss the hybrid approach implemented into the code FeynHiggs. In addition, we show how the refined Higgs mass prediction was used to define new MSSM Higgs benchmark scenarios.
We examine updated prospects for detecting WIMPs in supersymmetric models via direct and indirect dark matter search experiments. We examine several historical and also still viable scenarios: projections for well-tempered neutralinos (WTN), projections from the MasterCode (MC), BayesFits (BF) and Fittino (FO) collaborations, non-thermal wino dark matter (NThW) and finally mixed axion-higgsino dark matter from SUSY with radiatively-driven naturalness (RNS). The WTN is ruled out by recent limits from XENON and LUX collaborations. The NThW scenario, previously on tenuous ground due to gamma-line…
We use the Higgs coupling and the muon anomalous magnetic moment measurements to constrain the parameter space of the natural supersymmetry (SUSY) in the Generalized Minimal Supergravity (GmSUGRA) model. We scan the parameter space of the GmSUGRA model with small electroweak fine-tuning measure ($Δ_{\rm EW} \leq 100$). The parameter space after applying various sparticle mass bounds, Higgs mass bounds, B-physics bounds, the muon magnetic moment constraint, and the Higgs coupling constraint from measurements at HL-LHC, ILC, and CEPC, is shown in the planes of various interesting model parameter…
The minimal supersymmetric standard model (MSSM) with complex parameters can contribute sizably to muon/electron anomalous magnetic dipole momemnt ($g-2$) and electric dipole moment (EDM). The electron $g-2$ interplays with electron EDM; the muon $g-2$ can also interplay with electron EDM assuming the universality between smuon and selectron masses, either of which can constrain the relevant CP-phases in the MSSM. In this work, we first use such an interplay to derive an approximate analytical upper limit on the relevant CP-phase. Then we extensively scan the parameter space to obtain more acc…
The high statistics that will be collected during the LHC Run-II (and beyond) open the path to precision measurements at the TeV scale, where the PDFs will play a crucial role in BSM searches. In the di-lepton final state accurate measurements of the Forward-Backward Asymmetry (AFB) will be available, particularly in the invariant mass region around the Z peak. We show that this observable displays a statistical error which is competitive with that assigned to the existing PDF sets and which will rapidly become smaller than the latter as the integrated luminosity grows, thereby offering a mean…
We investigate how the constraint results of inflation models are affected by considering the latest local measurement of $H_0$ in the global fit. We use the observational data, including the Planck CMB full data, the BICEP2 and Keck Array CMB B-mode data, the BAO data, and the latest measurement of Hubble constant, to constrain the $Λ$CDM+$r$+$N_{\rm eff}$ model, and the obtained 1$σ$ and 2$σ$ contours of $(n_s, r)$ are compared to the theoretical predictions of selected inflationary models. We find that, in this fit, the scale invariance is only excluded at the 3.3$σ$ level, and $ΔN_{\rm eff…
Constraints from the decay B_s -> mu mu and LHC limits on Supersymmetry
纯轻子衰变B_s -> mu mu在标准模型（SM）中被强烈抑制，但在超对称性中可以有很大的增强，特别是在大的tanbe值下。从最近的LHC数据中对这个衰变通道的新限制已经被用来声称这些限制比直接搜索更能限制超对称参数空间。然而，直接搜索几乎不依赖于tanbe，而BR（B_s -> mu mu）与tanbe成正比^[6]。遗迹密度约束要求在参数空间的大区域中具有大的tanbe，这可能导致B_s -> mu mu的大值。然而，如果与遗迹密度相结合，BR（B_s -> mu mu）的实验上限并不比直接搜索和目前的Higgs极限更能约束CMSSM的参数空间。我们还观察到负干扰的超对称参数区域，其中B_s -> mu mu值比SM期望值低三倍，即使在大的tanbe值下。
We investigate to which extent the SUSY search results published by ATLAS and CMS in the context of simplified models actually cover the more realistic scenarios of a full model. Concretely, we work within the phenomenological MSSM (pMSSM) with 19 free parameters and compare the constraints obtained from SModelSv1.1.1 with those from the ATLAS pMSSM study in arXiv:1508.06608. We find that about 40-45% of the points excluded by ATLAS escape the currently available simplified model constraints. For these points we identify the most relevant topologies which are not tested by the current simplifi…
