arXiv subjects
Publications and source records attributed to G. Brooijmans.
Recent results on searches for new physics at Run II of the Tevatron are reported. The searches cover many different final states and previous hints of signals, but all analyses have at this point led to negative results.
Current experimental limits for new physics beyond the Standard Model and hints for deviations from Standard Model expectations will be reviewed, highlighting recent results. Possible signals that will be discussed include Higgs bosons, supersymmetric particles, large extra dimensions, new gauge bosons, dynamical symmetry breaking, muon g - 2, rare decays and lepton flavor violation. The discovery potential of the LHC and ILC will be presented, and the impact of discovery on answering fundamental questions of physics will be assessed.
The DZERO experiment located at Fermilab has recently started RunII with an upgraded detector. The RunII physics program requires the Data Acquisition to readout the detector at a rate of 1 KHz. Events fragments, totaling 250 KB, are readout from approximately 60 front end crates and sent to a particular farm node for Level 3 Trigger processing. A scalable system, capable of complex event routing, has been designed and implemented based on commodity components: VMIC 7750 Single Board Computers for readout, a Cisco 6509 switch for data flow, and close to 100 Linux-based PCs for high-level event filtering.
The DZERO experiment, located at the Fermi National Accelerator Laboratory, has recently started the Run 2 physics program. The detector upgrade included a new Data Acquisition/Level 3 Trigger system. Part of the design for the DAQ/Trigger system was a new monitoring infrastructure. The monitoring was designed to satisfy real-time requirements with 1-second resolution as well as non-real-time data. It was also designed to handle a large number of displays without putting undue load on the sources of monitoring information. The resulting protocol is based on XML, is easily extensible, and has spawned a large number of displays, clients, and other applications. It is also one of the few sources of detector performance available outside the Online System's security wall. A tool, based on this system, which provides for auto-recovery of DAQ errors, has been designed. This talk will include a description of the DZERO DAQ/Online monitor server, based on the ACE framework, the protocol, the auto-recovery tool, and several of the unique displays which include an ORACLE-based archiver and numerous GUIs.
The integrated luminosity at Run 2 of the Tevatron is approaching the Run 1 total, and data analysis is progressing. New results in searches for new physics by the DO experiment are presented in a variety of channels, demonstrating good performance of the detector and detailed understanding of the data.
During their exposure, nuclear emulsion sheets detect both tracks from experiment-related particles, as well as a considerable amount of background tracks, mainly due to cosmic rays. Unless the exposure has been fairly short, it is therefore fairly likely that a fraction of the tracks that have been identified as belonging to the particles the experiment is interested in, are really due to background. A method, which allows to measure this fraction reliably directly from the data, is described.
The general strategy, as well as channel-specific details, applied to the measurement of the top quark mass at the Tevatron in Run I are reviewed, and the combination of the results obtained by the CDF and DO collaborations presented. The accelerator and detector upgrades for Run II are described, and expected improvements in the systematic uncertainties on the measurement evaluated.
The formalism for neutrino flavor change induced by lepton family number violating interactions is developed for the three-neutrino case, and used to derive the corresponding flavor change probabilities in matter. Applied to the solar and atmospheric neutrino fluxes, it is argued that the observed anomalies, including the zenith dependence for the atmospheric case, could be due to such interactions.