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61 - Csaba Balazs 2014
I schematically, and very lightly, review some ideas that fuel model building in the field of baryogenesis. Due to limitations of space, and my expertise, this mini-review is incomplete and biased toward particle physics, especially supersymmetry.
Via a Bayesian likelihood analysis using 219 recent cosmic ray spectral data points we extract the anomalous part of the cosmic $e^pm$ flux. First we show that a significant tension exists between the $e^pm$ related and the rest of the fluxes. Interp reting this tension as the presence of an anomalous component in the $e^pm$ related data, we then infer the values of selected cosmic ray propagation parameters excluding the anomalous data sample from the analysis. Based on these values we calculate background predictions with theoretical uncertainties for PAMELA and Fermi-LAT. We find a statistically significant deviation between the Fermi-LAT $e^-+e^+$ data and the predicted background even when (systematic) uncertainties are taken into account. Identifying this deviation as an anomalous $e^pm$ contribution, we make an attempt to distinguish between various sources that may be responsible for the anomalous $e^pm$ flux.
We calculate Bayes factors to quantify how the feasibility of the constrained minimal supersymmetric standard model (CMSSM) has changed in the light of a series of observations. This is done in the Bayesian spirit where probability reflects a degree of belief in a proposition and Bayes theorem tells us how to update it after acquiring new information. Our experimental baseline is the approximate knowledge that was available before LEP, and our comparison model is the Standard Model with a simple dark matter candidate. To quantify the amount by which experiments have altered our relative belief in the CMSSM since the baseline data we compute the Bayes factors that arise from learning in sequence the LEP Higgs constraints, the XENON100 dark matter constraints, the 2011 LHC supersymmetry search results, and the early 2012 LHC Higgs search results. We find that LEP and the LHC strongly shatter our trust in the CMSSM (with $M_0$ and $M_{1/2}$ below 2 TeV), reducing its posterior odds by a factor of approximately two orders of magnitude. This reduction is largely due to substantial Occam factors induced by the LEP and LHC Higgs searches.
We isolated the anomalous part of the cosmic electron-positron flux within a Bayesian likelihood analysis. Using 219 recent cosmic ray spectral data points, we inferred the values of selected cosmic ray propagation parameters. In the context of the p ropagation model coded in GalProp, we found a significant tension between the electron positron related and the rest of the fluxes. Interpreting this tension as the presence of an anomalous component in the electron-positron related data, we calculated background predictions for PAMELA and Fermi-LAT based on the non-electron-positron related fluxes. We found a deviation between the data and the predicted background even when uncertainties, including systematics, were taken into account. We identified this deviation with the anomalous electron-positron contribution. We briefly compared this model independent signal to some theoretical results predicting such an anomaly.
In anticipation of data from the Large Hadron Collider (LHC) and the potential discovery of supersymmetry, in this work we seek an answer to the following: What are the chances that supersymmetry will be found at the LHC? Will the LHC data be enough to discover a given supersymmetric model? And what other measurements can assist the LHC establish the presence of supersymmetry? As a step toward answering these general questions, we calculate the odds of the next-to-minimal version of the popular supergravity motivated model (NmSuGra) being discovered at the LHC to be 4:3 (57 %). We also demonstrate that viable regions of the NmSuGra parameter space outside the LHC reach can be covered by upgrad
Applying a likelihood analysis to the next-to-minimal supergravity-motivated model, we identify parameter space regions preferred by present experimental limits from collider, astrophysical, and low energy measurements. We then show that favored regi ons are amenable to detection by a combination of the CERN Large Hadron Collider and an upgraded Cryogenic Dark Matter Search, provided that the more than three sigma discrepancy in the difference of the experimental and the standard theoretical values of the anomalous magnetic moment of the muon prevails in the future.
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