The authors present the results of a search for anomalous production of diphoton events with large missing transverse energy using the Collider Detector at Fermilab. In 202 pb-1 of p$ar{p}$ collisions at √s = 1.96 TeV they observe no candidate events, with an expected standard model background of 0.27 ± 0.07(stat) ± 0.10(syst) events. The results exclude a lightest chargino of mass less than 167 GeV/c2, and lightest neutralino of 93 GeV/c2 at 95% confidence level in a gauge-mediated supersymmetry-breaking model with a light gravitino.

The authors present the results of a search for anomalous production of diphoton events with large missing transverse energy using the Collider Detector at Fermilab. In 202 pb[sup -1] of p[bar p] collisions at [radical]s = 1.96 TeV they observe no candidate events, with an expected standard model background of 0.27 [+-] 0.07(stat) [+-] 0.10(syst) events. The results exclude a lightest chargino of mass less than 167 GeV/c[sup 2], and lightest neutralino of 93 GeV/c[sup 2] at 95% confidence level in a gauge-mediated supersymmetry-breaking model with a light gravitino.

The authors present the results of a search for anomalous production of diphoton events with large missing transverse energy using the Collider Detector at Fermilab. In 202 pb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV they observe no candidate events, with an expected standard model background of 0.27 {+-} 0.07(stat) {+-} 0.10(syst) events. The results exclude a lightest chargino of mass less than 167 GeV/c{sup 2}, and lightest neutralino of 93 GeV/c{sup 2} at 95% confidence level in a gauge-mediated supersymmetry-breaking model with a light gravitino.

This dissertation presents a search for heavy, long-lived, neutral particles that decay to photons in proton anti-proton collisions with a center of mass energy of 1.96 TeV at the Collider Detector at Fermilab (CDF) experiment. Such particles are typical of models of Gauge Mediated Supersymmetry Breaking (GMSB). We select events with a single photon, missing transverse energy, and little other activity in the detector. We model the photon arrival time for Standard Model and non-collision sources using a data-driven method and consider photons which have a time of arrival at the detector which is significantly delayed relative to predictions. Using 6.3 fb-1 of data collected from December 2004 to June 2010, we observe 322 events in the signal region compared to a background prediction of 287 ± 24 events. While the data are consistently above predictions, we report a model excess with a significance of 1.2 standard deviations from the null hypothesis.

We present the results of a search in p[bar p] collisions at[radical]s= 1.8 TeV for anomalous production of events containing a photon with large transverse energy and a lepton (e or[mu]) with large transverse energy, using 86 pb[sup -1] of data collected at the Collider Detector at Fermilab during the 1994-95 collider run at the Fermilab Tevatron. The presence of large missing transverse energy (E[sub T]), additional photons, or additional leptons in these events is also analyzed. The results are consistent with standard model expectations, with the possible exception of photon-lepton events with large E[sub T], for which the probability of a statistical fluctuation of the standard model expectation up to and above the observed level is 0.7%.

This dissertation presents a search for long-lived particles using delayed photons in proton-proton collisions at sqrt(s) = 13 TeV recorded by the Compact Muon Solenoid (CMS) experiment at the CERN Large Hadron Collider in 2017, corresponding to an integrated luminosity of 41.5 fb^-1. This analysis includes a number of unique components that will be discussed: a dedicated signal trigger, out-of-time photon reconstruction and identification, and a detector time resolution measurement. The results of this search include the combination of a related analysis using data collected in 2016 also at sqrt(s) = 13 TeV, corresponding to a combined integrated luminosity of 77.4 fb^-1. The combined results are interpreted in the context of supersymmetry with gauge-mediated supersymmetry breaking, where the neutralino is long-lived and decays to a photon and a gravitino. Limits are presented as a function of the neutralino proper decay length and mass. For neutralino proper decay lengths of 10^1, 10^2, 10^3, and 10^4 cm, masses up to 320, 525, 360, and 215 GeV are excluded at 95% confidence level, respectively. Additionally, a discussion on a high-performance computing upgrade to CMS, known as mkFit, will be presented. mkFit is an on-going effort to exploit highly parallel computer architectures in vectorizing and parallelizing combinatorial Kalman filter charged particle track reconstruction algorithms. The current physics and computational performance of this project will be discussed.