Search for Supersymmetry with Diphoton Events in 7 TeV pp Collisions at the Compact Muon Solenoid

This dissertation describes the search for General Gauge Mediated (GGM) supersymmetry breaking in 7 TeV center-of-mass proton-proton collisions from the Large Hadron Collider (LHC); the total integrated luminosity of data analyzed was 35.5 ± 3.9 pb-1 from the 2010 data taking. In GGM scenarios, a pair of supersymmetric particles is formed through strong production; each is expected to decay into jets, a photon, and a gravitino. Hence, searches for events with two photons and at least one jet were carried out; one observed event with missing transverse energy (MET) \u3e 50 GeV was found. This is consistent within statistical fluctuations of the predicted Standard Model background from QCD and EW sources, 1.11±0.76 events. For one set of GGM parameters, the predicted cross-section (in leading order and next-to-leading order) is 2.309±0.413 pb, leading to a predicted number of events with MET \u3e 50 GeV of 17.1±3.7. Given the number of observed events and the expected background, an upper limit cross section of 0.558 pb was set and the model point was excluded. Upper limit calculations and exclusion regions were calculated for gluino and squark masses of 400 − 2000 GeV and neutralino masses of 50 GeV, 150 GeV, and 500 GeV

End-to-End Document Classification and Key Information Extraction using Assignment Optimization

We propose end-to-end document classification and key information extraction (KIE) for automating document processing in forms. Through accurate document classification we harness known information from templates to enhance KIE from forms. We use text and layout encoding with a cosine similarity measure to classify visually-similar documents. We then demonstrate a novel application of mixed integer programming by using assignment optimization to extract key information from documents. Our approach is validated on an in-house dataset of noisy scanned forms. The best performing document classification approach achieved 0.97 f1 score. A mean f1 score of 0.94 for the KIE task suggests there is significant potential in applying optimization techniques. Abation results show that the method relies on document preprocessing techniques to mitigate Type II errors and achieve optimal performance.Comment: 10 pages, 5 figure

Relaxation of Spin Polarized 3^3He in Mixtures of 3^3He and 4^4He Below the 4^4He Lambda Point

We report the first study of the depolarization behavior of spin polarized 3He in a mixture of 3He-4He at a temperature below the 4He Lambda point in a deuterated TetraPhenyl Butadiene-doped deuterated PolyStyrene (dTPB-dPS) coated acrylic cell. In our experiment the measured 3He relaxation time is due to the convolution of the 3He longitudinal relaxation time, T1, and the diffusion time constant of 3He in superfluid 4He since depolarization takes place on the walls. We have obtained a 3He relaxation time ~3000 seconds at a temperature around 1.9K. We have shown that it's possible to achieve values of wall depolarization probability on the order of (1-2)x10^-7 for polarized 3He in the superfluid 4He from a dTPB-dPS coated acrylic surface.Comment: The Model used to interpret the data has been change