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PHYS 3446 Lecture #1 Monday Aug 25, 2008 Dr. Andrew Brandt 1.Syllabus and Introduction 2.HEP Infomercial Thanks to Dr. Yu for developing electronic version of this class Please turn off your cell-phones, pagers and laptops in class http://www-hep.uta.edu/~brandta/teaching/fa2008/teaching.html
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Course Material Nuclear Physics –Models of atom –Cross sections –Radiation High Energy Experimental Techniques –Energy deposition in matter –Particle detector techniques and detectors –Accelerators HEP Phenomenology –Elementary particle interactions –Symmetries –The Standard Model –Beyond the Standard Model
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Attendance and Class Style Attendance: STRONGLY –is STRONGLY encouraged, to aid your motivation I give pop quizzes Class style: –Lectures will be primarily on electronic media The lecture notes will be posted AFTER each class –Will be mixed with traditional methods (blackboard) STRONGLY –Active participation through questions and discussion are STRONGLY encouraged
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Grading Midterms: 40% –2 Tests 20% each (Oct. 13, Nov. 24) –No Final –Exams will be curved if necessary –No makeup tests Homework: 20% (No late homework) Lab score: 20% (More about lab on Weds.) Pop Quizzes: 10% Project: 10% (report on significant result in nuclear/particle physics)
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High Energy Physics at UTA UTA faculty Andrew Brandt, Kaushik De, Amir Farbin, Andrew White, Jae Yu along with many post-docs, graduate and undergraduate students investigate the basic forces of nature through particle physics studies at the world’s highest energy accelerators In the background is a photo of a sub-detector of the 5000 ton DØ detector. This sub-detector was designed and built at UTA and is currently operating at Fermi National Accelerator Laboratory near Chicago.
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Structure of Matter cm Matter 10 -9 m Molecule 10 -10 m 10 -14 m AtomNucleus Atomic Physics Nuclear Physics High energy means small distances Nano-Science/Chemistry 10 -15 m u <10 -18 m QuarkBaryon Electron <10 -19 m protons, neutrons, mesons, etc. top, bottom, charm, strange, up, down High Energy Physics (Hadron) (Lepton)
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Periodic Table All atoms are made of protons, neutrons and electrons HeliumNeon u d u u d d Proton Neutron Electron Gluons hold quarks together Photons hold atoms together
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What is High Energy Physics? Matter/Forces at the most fundamental level. STANDARD MODEL Great progress! The “STANDARD MODEL” BUT… many mysteries => Why so many quarks/leptons?? => Why four forces?? Unification? => Where does mass come from?? => Are there higher symmetries?? What is the “dark matter”?? Will the LHC create a black hole that destroys the Earth? NO! See: http://public.web.cern.ch/Public/en/LHC/Safety-en.html
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Role of Particle Accelerators Smash particles together Act as microscopes and time machines –The higher the energy, the smaller object to be seen –Particles that only existed at a time just after the Big Bang can be made Two method of accelerator based experiments: –Collider Experiments: p p, pp, e + e -, ep –Fixed Target Experiments: Particles on a target –Type of accelerator depends on research goals
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Fermilab Tevatron and CERN LHC Currently Highest Energy proton-anti-proton collider –E cm =1.96 TeV (=6.3x10 -7 J/p 13M Joules on 10 -4 m 2 ) Equivalent to the K.E. of a 20 ton truck at a speed 81 mi/hr Chicago Tevatron pp p CDF DØ Fermilab: http://www.fnal.gov/ ; DØ: http://www-d0.fnal.gov/ CERN: http://www.cern.ch/ ; ATLAS: http://atlas.web.cern.ch/ Highest Energy proton- proton collider in fall 2008 –E cm =14 TeV (=44x10 -7 J/p 1000M Joules on 10 -4 m 2 ) Equivalent to the K.E. of a 20 ton truck at a speed 711 mi/hr 1500 physicists 130 institutions 30 countries 5000 physicists 250 institutions 60 countries
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The International Linear Collider 33km= 21mi European Design 500 GeV (800 GeV) 47 km =29 mi US Design 500 GeV (1 TeV) Long~ linear electron-position colliders Optimistically 15 years from now Takes 10 years to build an accelerator and the detectors
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Particle Identification Interaction Point electron photon jet muon neutrino -- or any non-interacting particle missing transverse momentum Ä B Scintillating Fiber Silicon Tracking Charged Particle Tracks Calorimeter (dense) EMhadronic Energy Wire Chambers Magnet Muon Tracks We know x,y starting momenta is zero, but along the z axis it is not, so many of our measurements are in the xy plane, or transverse
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DØ Detector Weighs 5000 tons As tall as a 5 story building Can inspect 3,000,000 collisions/second Record 100 collisions/second Records 10 Mega-bytes/second Recording 0.5x10 15 (500,000,000,000,000) bytes per year (0.5 PetaBytes). 30’ 50’ ATLAS Detector Weighs 10,000 tons As tall as a 10 story building Can inspect 1,000,000,000 collisions/second Will record 200 collisions/second Records 300 Mega-bytes/second Will record 2.0x10 15 (2,000,000,000,000,000) bytes each year (2 PetaByte).
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The Standard Model Current list of elementary (i.e. indivisible) particles Antiparticles have opposite charge, same mass The strong force is different from E+M and gravity! new property, color charge confinement - not usual 1/r 2 Standard Model has been very successful but has too many parameters, does not explain origin of mass. Continue to probe and attempt to extend model.
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UTA and Particle Physics Fermilab/Chicago CERN/Geneva ILC? U.S.?
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Building Detectors at UTA
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High Energy Physics Training + Jobs EXPERIENCE: 1)Problem solving 2)Data analysis 3)Detector construction 4)State-of-the-art high speed electronics 5)Computing (C++, Python, Linux, etc.) 6)Presentation 7)Travel JOBS: 1)Post-docs/faculty positions 2)High-tech industry 3)Computer programming and development 4)Financial
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My Main Research Interests Physics with Forward Proton Detectors Fast timing detectors Triggering (selecting the events to write to tape): at ATLAS 200/40,000,000 events/sec
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DØ Forward Proton Detector (FPD) Quadrupole Spectrometers surround the beam: up, down, in, out use quadrupole magnets (focus beam) - a series of momentum spectrometers that make use of accelerator magnets in conjunction with position detectors along the beam line Dipole Spectrometer inside the beam ring in the horizontal plane use dipole magnet (bends beam) also shown here: separators (bring beams together for collisions) A total of 9 spectrometers comprised of 18 Roman Pots Data taking finished, analysis in progress (Mike Strang Ph.D.)
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Detector Construction At the University of Texas, Arlington (UTA), scintillating and optical fibers were spliced and inserted into the detector frames. The cartridge bottom containing the detector is installed in the Roman pot and then the cartridge top with PMT’s is attached.
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One of the DØ Forward Proton Detectors built at UTA and installed in the Tevatron tunnel Tevatron: World’s Highest Energy Collider Fermilab DØDØ High-tech fan
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FP420: Particle physics R&D collaboration that proposes to use double proton tagging at 420m as a means to discover new physics FP420 Overview NEW
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Central Exclusive Higgs Production pp p H p : 3-10 fb beam p’ roman pots dipole E.g. V. Khoze et al M. Boonekamp et al. B. Cox et al. V. Petrov et al… Levin et al… M = O(1.0 - 2.0) GeV Idea: Measure the Missing mass from the protons H gap -jet p p Arnab Pal
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n=1n>>1 Cerenkov Effect Use this property of prompt radiation to develop a fast timing counter particle
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Background Rejection Ex, Two protons from one interaction and two b-jets from another Fast Timing Detectors for ATLAS WHO? UTA (Brandt), Alberta, Louvain, FNAL WHY? How? Use timing to measure vertex and compare to central tracking vertex How Fast? 10 picoseconds (light travels 3mm in 10 psec!) photon Pedro Duarte (M.S.) Shane Spivey Ian Howley proton MCP-PMT
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Fused Silica Bars 9 cm bars Some converted to mini-bars 60 psec Spread in timing as f( ) since n( ) Simulation by Joaquin Noyola (UG) other studies by UG Chance Harenza+ Alek Malcolm
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MCP-PMT Operation Faceplate Photocathode Dual MCP Anode Gain ~ 10 6 Photoelectron V ~ 200V V ~ 2000V photon
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Test Beam Fermilab Test beam T958 experiment to study fast timing counters for FP420 (Brandt spokesman) Used prototype detector to test concept Test beam at Fermilab Sep. 2006, Mar.+Jul. 2007 CERN October 2007, June 2008 Time resolution for the full detector system: 1. Intrinsec detector time resolution 2. Jitter in PMT's 3. Electronics (AMP/CFD/TDC)
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Latest QUARTIC Prototype Testing long bars 90 cm, more light than 15 mm mini-bars (due to losses in air light-guide) but more time dispersion due to n( )
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FP420 Timing Setup
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Data Acquisition Lecroy 8620A 6 GHz 20 Gs Lecroy 7300A 3 GHz 20/10 Gs Remotely operated from control room Transfer data periodically with external USB drive
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Good Event 5 ns/major division
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Online Screen Capture one histo is 10 ps per bin others are 20 ps delta time between channels
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Dt QUARTIC Long Bar Resolution 56.6/1.4=40 ps/bar including CFD!
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Undergraduate Student Research Opportunities Several aspects of fast timing project are short of (wo)manpower: 1)Helping to setup and operate laser test stand 2)Operating/improving ray tracing simulation 3)Commercial ray tracing program to aid in simulation 4)HEP detector simulation GEANT4 5)Test beam data analysis Experience with C++ required for some but not all of the projects Some funding available (results oriented)
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Laser Test Stand Argonne National Lab setup Use Hamamatsu picosecond laser to measure timing of PMT, electronics
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QUARTIC Bar Length Studies 20 ps 15mm bar/75 mm lightguide 40 ps 90mm bar
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Summary If you are here to learn about Nuclear/Particle Physics this should be an interesting and fun class, if you are here because you need four hours of physics…. a) get out while you still can OR b) it will still be an interesting and fun class (up to you) It is an opportunity to learn about high energy physics from a high energy physicist Lab takes time, there will be reading outside of main text See me if interested in UG research project
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