Search for New Physics in the Exclusive Gamma+MET Final State in p-pbar Collisions at Sqrt(s) = 1.96 TeV

• Main Author: Aurisano, Adam 1982-
• Other Authors: Toback, David
• Format: Others
• Published: 2013
• Subjects: LNG; Tevatron; CDF; Delayed photons; GMSB
• Online Access: http://hdl.handle.net/1969.1/148427

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.