Sharif Digital Repository

We search for supersymmetry in the same-sign dilepton final state in the first 35 pb1 of data collected by the CMS detector and find no evidence of new physics at this point. Since true same-sign physics backgrounds, such asWWjj, are negligible for this amount of integrated luminosity, we focus our attention on data-driven estimations of the backgrounds where one (W+jets and tt backgrounds) or both of the leptons (QCD background) are fake. We use the generalized fake ratio method documented to estimate the rates for these fake backgrounds. Another source of backgrounds in the case of electrons is the charge-flip, where the charge of one of the electrons in an opposite-sign di-electron pair... 

Among the proposals for new physics, Supersymmetry is the most popular to gradually appear at a yet unreached center-of-mass energy at the Large Hadron Collider (LHC). However, that doesn’t seem very likely. This thesis represents a search for any evidence of a minimal supergravity inspired scenario (mSUGRA) of R-parity conserving supersymmetry at the Compact Muon Solenoid (CMS) experiment. The analysis employs an event topology , which consists primarily of opposite-sign di-leptons accompanied by hadronic jets and missing transverse energy. The search utilizes data produced by the proton-proton collision of the LHC at a center-of-mass energy p s = 7 TeV and recorded by the CMS detector in... 

As more renewables step in, the ongoing change will be drastic for the electrical grid. The energy sector must find new ways to balance energy production and consumption. Electric vehicle (EV) batteries are by far the most cost-efficient form of energy storage since they require no additional investments in hardware. A bidirectional EV charger is a new technology that enables energy to be pushed back to the power grid and auxiliary loads from the battery. The electrical requirements of the EV charger are examined in detail to find an appropriate power electronics converter to meet all the requirements. The CLLC resonant converter is a promising candidate for high efficient, bidirectional...