1. Feb 1, 2010 Experimental Particle Physics 1 Elementary Particle Physics Experiment: The ATLAS experiment at the LHC University of Massachusetts, Amherst Graduate Research Orientation 1 Feb 2010

2. Feb 1, 2010 Experimental Particle Physics 2 The UMass ATLAS Group Faculty – –Ben Brau - LGRT 1032 – –Carlo Dallapiccola - LGRT 1038 – –Stephane Willocq - LGRT 1042 Postdoctoral Researchers – –Ed Moyse, Elisa Pueschel, Niels Van Eldik, Martin Woudstra - CERN Graduate Students – –Andrew Meade, Emily Thompson - CERN – –German Colon, Preema Pais, Tulin Verol - LGRT 1036

3. Feb 1, 2010 Experimental Particle Physics 3 Experiments can address long standing puzzles / questions:  What are the fundamental constituents of matter?  What are the fundamental forces between elementary particles?  Can the forces of nature be unified? Including gravity?  What is the origin of mass?  What is the origin of the matter-antimatter asymmetry of the Universe?  What is dark matter?  Are there extra dimensions? + many more… What is Particle Physics About?

4. Feb 1, 2010 Experimental Particle Physics 4 How can we answer these Fundamental Questions? Particle Accelerators – –Reach very high collision energies to probe extremely small distance scales (< 10 -18 m) – –Research at the energy frontier (a few TeV) with the ATLAS experiment at the Large Hadron Collider (LHC)  10 x higher energy than previous colliders  search for Higgs boson (origin of mass?) SuperSymmetric particles (dark matter candidate?) New interactions (heavy gauge bosons, extra dimensions?)

5. Feb 1, 2010 Experimental Particle Physics 5 The Large Hadron Collider (LHC) Proton-proton collider circumference = 27 km Energy = 7 TeV / beam √s = 14 TeV Stored energy / beam = 350 MJ (!) Bunch spacing = 25 ns  40 MHz crossing rate Design luminosity = 10 34 cm -2 s -1 Number of interactions per crossing ~23 Collisions expected in late 2009 Run for ~10-15 years Lake Geneva  14 TeV CMS ATLAS CERN Main Site 

6. Feb 1, 2010 Experimental Particle Physics 6 Inner Tracker EM Calorimeter Hadronic Calorimeter Muon Detectors Diameter25 m Barrel toroid length26 m End-cap end-wall chamber span46 m Overall weight 7000 Tons The ATLAS Detector @ LHC

7. Feb 1, 2010 Experimental Particle Physics 7

8. Feb 1, 2010 Experimental Particle Physics 8 ▪ November 2005 September 2006 August 2006 February 2008

9. Feb 1, 2010 Experimental Particle Physics 9 ATLAS Data Event

10. Feb 1, 2010 Experimental Particle Physics 10 UMass Work on ATLAS Software development for Muon Spectrometer – –Leading muon reconstruction effort (SW co-coordinator, EM event data model leader) – –Validation of detector description, performance improvements Physics analysis = Search for new physics – –Search for new heavy gauge bosons (new interactions) – –Alternatives to Higgs mechanism (origin of mass) – –Signs of extra (large) dimensions: micro black holes – –Model-Independent: Hints of things we haven’t thought of yet More information at http://people.umass.edu/eppex/ http://people.umass.edu/eppex/

11. Feb 1, 2010 Experimental Particle Physics 11 LHC Schedule First Physics Run at 3.5 GeV on 3.5 GeV begins now. Run will continue through 2010 and 2011, with a goal luminosity of 1 fb -1. All splices will be repaired in a long (~year) shutdown. High-energy 7GeV on 7GeV will begin ~2013.