Supersymmetric Dark Matter or Not

The lack of evidence for low energy supersymmetry at the LHC implies a supersymmetry scale in excess a TeV. While this is consistent (and even helpful) with a Higgs boson mass at $\approx$ 125 GeV, simple supersymmetric models with scalar and gaugino mass universality are being pushed into strips of parameter space. These often require coannihilations to obtain an acceptable relic density and the extent of these coannihilation strips will be discussed. In contrast, non-supersymmetric grand unified theories such as SO(10) may also provide a dark matter candidate. Because of the presence of an intermediate scale, these theories may unify gauge couplings, provide for neutrino masses and a suitably long lived proton.Comment: 18 pages, 13 figures, Summary of talk given at the 11th International Workshop Dark Side of the Universe 2015, Dec 2015, Kyoto, Japa

Performance of the CMS tracking detectors from the 2009 LHC run

The 2009 run provided the first proton-proton collisions from the Large Hadron Collider (LHC) at center of mass energies of 900 GeV and 2.36 TeV. The Compact Muon Solenoid (CMS) experiment has recorded a large sample of minimum bias events from these collisions. We present results from the all silicon tracking detectors from this run. The performance of the tracker and track reconstruction algorithms are considered including signal-to-noise, efficiencies and comparisons to simulation for track parameter and resonance reconstruction performance.Comment: 4 pages, 3 figures, proceedings from the 2010 Lake Louise Winter Institut

Heavy Flavor Production at CMS

Measurements of heavy flavor production in pp collisions at sqrt(s) = 7.0 TeV recorded at the CMS experiment are presented. Double differential cross sections with respect to transverse momentum and rapidity are shown for J/Psi and Upsilon(1S), Upsilon(2S), and Upsilon(3S). The inclusive open beauty rate is measured with two different techniques, including a study of the angular correlations between b jets in events with two identified b jets. Lastly, the B+, B0, and B0s production rates are measured from the reconstruction of exclusive final states.Comment: Proceedings from talk given at Rencontres de Moriond QCD 2011 on behalf of the CMS collaboration. 4 pages, 3 figure

Notes on The Feynman Checkerboard Problem

The Feynman checkerboard problem is an interesting path integral approach to the Dirac equation in `1+1' dimensions. I compare two approaches reported in the literature and show how they may be reconciled. Some physical insights may be gleaned from this approach.Comment: 9 page

Supersymmetry Searches with Multiple b-jets at CMS

Recent results from CMS are reviewed for searches for supersymmetry in final states with multiple bottom quark jets. Results are based on the full 2012 CMS dataset consisting of 19.5 fb-1 collected at a center-of-mass energy of sqrt(s) = 8 TeV. In particular, searches for final states with multiple b-jets and one or two leptons are presented. These final states are of special interest in the context of the search for third generation squarks in gluino or sbottom cascade decays, as predicted by natural supersymmetry.Comment: Proceedings for presentation at the 2013 European Physical Society Conference on High Energy Physics, Stockholm, Sweden, 18-24 July, 201