Search For Diphoton Events With Large Missing Transverse Energy In 63 Fb 1 Of Pbarp Collisions Using The D0 Detector At The Fermilab Tevatron Collider

A search for diphoton events with large missing transverse energy produced in p{bar p} collisions at √s = 1.96 TeV is presented. The data were collected with the D0 detector at the Fermilab Tevatron Collider between 2002 and 2010, and correspond to 6.3 fb−1 of integrated luminosity. The observed missing transverse energy distribution is well described by the Standard Model prediction, and 95% C.L. limits are derived on two realizations of theories beyond the Standard Model. In a gauge mediated supersymmetry breaking scenario, the breaking scale [Lambda] is excluded for [Lambda]

A search for diphoton events with large missing transverse energy produced in p$ar{p}$ collisions at √s = 1.96 TeV is presented. The data were collected with the D0 detector at the Fermilab Tevatron Collider between 2002 and 2010, and correspond to 6.3 fb-1 of integrated luminosity. The observed missing transverse energy distribution is well described by the Standard Model prediction, and 95% C.L. limits are derived on two realizations of theories beyond the Standard Model. In a gauge mediated supersymmetry breaking scenario, the breaking scale ? is excluded for ? 124 TeV. In a universal extra dimension model including gravitational decays, the compactification radius Rsubc/sub is excluded for Rsubc/subsup-1

We report a search for diphoton events with large missing transverse energy produced in p{bar p} collisions at √s = 1.96 TeV. The data were collected with the D0 detector at the Fermilab Tevatron Collider, and correspond to 6.3 fb−1 of integrated luminosity. The observed missing transverse energy distribution is well described by the standard model prediction, and 95% C.L. limits are derived on two realizations of theories beyond the standard model. In a gauge mediated supersymmetry breaking scenario, the breaking scale [Lambda] is excluded for [Lambda]

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.

A search was conducted for evidence of large extra dimensions (LED) at Fermi National Accelerator Laboratory's Tevatron using the D0 detector. The Tevatron is a p{bar p} collider at a center of mass energy of 1.96 TeV. Events with particles escaping into extra dimensions will have large missing energy. The search was carried out using data from a total luminosity of 197 {+-} 13 pb{sup -1} with an observable high transverse momentum photon and a large transverse missing energy. The 70 observed events are consistent with photons produced by standard known reactions plus other background processes produced by cosmic muons. The mass limits on the fundamental mass scale at 95% confidence level for large extra dimensions of 2, 4, 6 and 8 are 500 GeV, 581 GeV, 630 GeV, and 668 GeV respectively.

This dissertation presents the results of the first search for heavy, neutral, longlived particles that decay to photons at a hadron collider. We use a sample of +jet+missing transverse energy events in $p \bar{p}$ collisions at √s = 1.96 TeV taken with the Collider Detector at Fermilab. Candidate events are selected based on the arrival time of a high-energy photon at the electromagnetic calorimeter as measured with a timing system that was recently installed. The final result is that we find 2 events, using 570±34 pb-1 of data collected during 2004-2005 at the Fermilab Tevatron, consistent with the background estimate of 1.3±0.7 events. While our search strategy does not rely on model-specific dynamics, we interpret this result in terms of cross section limits in a supersymmetric model with $\vec{X}$$0\atop{1}$ eG and set a world-best e 01 mass reach of 101 GeV/c2 at e = 5 ns. We can exclude any [gamma]+jet+missing transverse energy signal that would produce more than 5.5 events.

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.

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%.