The SLAC ATLAS group
The ATLAS group at SLAC is hosting a wide spectrum of activities on the ATLAS experiment from detector and computing to explorations of LHC physics. ATLAS is supported as a top priority of SLAC HEP program, taking over from BaBar as the main high-energy physics activity. We have two professors (Su Dong, Ariel Schwartzman), several senior staff scientists (Tim Barklow, Rainer Bartoldus, Philippe Grenier, Richard Mount, Charlie Young), a Panofsky Fellow (Giacinto Piacquadio), 3 postdocs and termed staff, and 5 graduate students. In addition, there is also a strong team of professional staff and engineers with computing and detector expertise for our experimental involvement.
Physics
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Our physics activities focus on searches for new physics and also developing several Higgs physics topics. Our SUSY search efforts are concentrating on searches of 3rd generation sQuarks through b+MET+jets final-state and dedicated direct "stop" search with 1 lepton+jets+MET, which are the most sensitive searches for gluino mediated and direct production respectively. SLAC group is also a major player in several areas of the next frontier for Higgs physics, including SUSY Higgs decaying to bbbar and boosted Standard Model (SM) Higgs decaying to bbbar, as well as SM Higgs decaying to Z+gamma. We have also already concluded some SM physics measurements of jet properties and event shapes, and top quark production with fully hadronic decay modes. Several exotic searches already yielded first results: gluinos which have come to rest in the calorimeter and decay during empty bunch crossings, excess like-sign leptons, a 4th generation quark, R-Parity violating Supersymmetry in multi-jet and long-lived particle final states, light pseudoscalar Higgs in the NMSSM, and "lepton-jets", while search for heavy particle decaying two boosted Higgs bosons and search for "quirks" are currently in progress. Another key physics venue is the reconstruction of heavily boosted objects through jet substructure which is a distinctive new high energy playground at the LHC. Many tools are developed for use in these analyses, in conjunction with an extensive program on jet reconstruction/calibration effort which involves a leading role in ATLAS. A pioneering exploration of modern machine learning techniques started a new line of jet imagine processing development. There is also strong expertise in heavy flavor tagging within the group through both ATLAS effort and previous experiments. Current activity includes spearheading the double b hadron tagging and track-jet based b-tagging efforts.The SLAC group also has been carrying significant responsibilities on trigger operations and algorithm development which has close connections to physics strategy. SLAC is a Tier2 computing facility, and provides strong support for data analysis and simulation efforts. Further details can be found on the SLAC ATLAS physics page.
Detector
The group plays a major role in the operation of the Pixel detector and the design/construction of the near term upgrades, building on SLAC's long experience in silicon detector technology. We have been in particular involved in several areas of the pixel Insertable B-Layer (IBL) project which was successfully installed in 2014. We are also very involved in the triggers and data-acquisition (TDAQ) system, working on the TDAQ software and infrastructure, as well as high-level triggers and online beam spot. SLAC is also a leading force in the muon Cathode Strip Chamber readout rebuild with a modern DAQ concept on the ATCA platform which has been installed in 2014. We contribute strongly to the simulation software, with expertise in GEANT4 modeling. The XROOTD utility developed at SLAC is a primary tool for data storage and access in LHC experiments. SLAC has also engaged actively in several projects that will address the planned ATLAS upgrades, including the future tracking upgrade and Trigger/DAQ upgrades. Extensive activities on silicon sensor development include the pioneering radiation hard 3D pixel sensors for IBL and the more recent CMOS sensor development for HL-LHC upgrade. High speed data transmission is another active area that spans from IBL to future pixel upgrades. A major theme expands into various subsystems is data acquisition based on cutting-edge serial I/O + FPGA technology.
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Some further details of the SLAC ATLAS activities can be found on the SLAC ATLAS page (some areas are not quite up to date). Since 2014, a new ATLAS group is also established at the Stanford Physics Department with Prof. Lauren Tompkins in a joint ATLAS effort.