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PHYS 3446 Lecture #1. Monday Aug 25, 2008 Dr. Andrew Brandt. Syllabus and Introduction HEP Infomercial. Please turn off your cell-phones, pagers and laptops in class. Thanks to Dr. Yu for developing electronic version of this class.
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PHYS 3446 Lecture #1 Monday Aug 25, 2008 Dr. Andrew Brandt • Syllabus and Introduction • HEP Infomercial Please turn off your cell-phones, pagers and laptops in class Thanks to Dr. Yu for developing electronic version of this class http://www-hep.uta.edu/~brandta/teaching/fa2008/teaching.html
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
Attendance and Class Style • Attendance: • 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) • Active participation through questions and discussion are STRONGLY encouraged
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)
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.
Matter Molecule Atom Nucleus Baryon Quark (Hadron) u 10-14m cm 10-9m 10-10m 10-15m <10-19m top, bottom, charm, strange, up, down protons, neutrons, mesons, etc. p,W,L... Atomic Physics Nuclear Physics Electron (Lepton) <10-18m High Energy Physics Structure of Matter Nano-Science/Chemistry High energy means small distances
Periodic Table Helium Neon u d u u d d All atoms are made of protons, neutrons and electrons Electron Neutron Proton Gluons hold quarks together Photons hold atoms together
What is High Energy Physics? • Matter/Forces at the most fundamental level. • 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
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
Chicago CDF p DØ Tevatron p Fermilab Tevatron and CERN LHC • Highest Energy proton-proton collider in fall 2008 • Ecm=14 TeV (=44x10-7J/p 1000M Joules on 10-4m2) • Equivalent to the K.E. of a 20 ton truck at a speed 711 mi/hr • Currently Highest Energy proton-anti-proton collider • Ecm=1.96 TeV (=6.3x10-7J/p 13M Joules on 10-4m2) • Equivalent to the K.E. of a 20 ton truck at a speed 81 mi/hr 1500 physicists 130 institutions 30 countries 5000 physicists 250 institutions 60 countries CERN: http://www.cern.ch/ ; ATLAS: http://atlas.web.cern.ch/ Fermilab: http://www.fnal.gov/ ; DØ: http://www-d0.fnal.gov/
European Design500 GeV (800 GeV) 33km= 21mi 47 km =29 mi US Design500 GeV (1 TeV) The International Linear Collider • Long~ linear electron-position colliders • Optimistically 15 years from now • Takes 10 years to build an accelerator and the detectors
Calorimeter (dense) Muon Tracks Charged Particle Tracks Energy Scintillating Fiber Silicon Tracking Interaction Point Ä B EM hadronic Magnet Wire Chambers Particle Identification electron photon jet muon 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 neutrino -- or any non-interacting particle missing transverse momentum
DØ Detector 30’ 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 2.0x1015 (2,000,000,000,000,000) bytes each year (2 PetaByte). • 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 0.5x1015 (500,000,000,000,000) bytes per year (0.5 PetaBytes).
The Standard Model 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. • 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/r2
UTA and Particle Physics Fermilab/Chicago CERN/Geneva ILC? U.S.?
High Energy Physics Training + Jobs • EXPERIENCE: • Problem solving • Data analysis • Detector construction • State-of-the-art high speed electronics • Computing (C++, Python, Linux, etc.) • Presentation • Travel • JOBS: • Post-docs/faculty positions • High-tech industry • Computer programming and development • Financial
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
DØ Forward Proton Detector (FPD) - a series of momentum spectrometers that make use of accelerator magnets in conjunction with position detectors along the beam line • Quadrupole Spectrometers • surround the beam: up, down, in, out • use quadrupole magnets (focus beam) • 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.)
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.
Tevatron: World’s Highest Energy Collider Fermilab DØ High-tech fan One of the DØ Forward Proton Detectors built at UTA and installed in the Tevatron tunnel
NEW FP420 Overview FP420: Particle physics R&D collaboration that proposes to use double proton tagging at 420m as a means to discover new physics
-jet gap gap H h p p -jet beam dipole dipole p’ p’ roman pots roman pots Central Exclusive Higgs Production pp p H p : 3-10 fb E.g. V. Khoze et al M. Boonekamp et al. B. Cox et al. V. Petrov et al… Levin et al… Idea: Measure the Missing mass from the protons M = O(1.0 - 2.0) GeV Arnab Pal
particle Cerenkov Effect n=1 n>>1 Use this property of prompt radiation to develop a fast timing counter
proton Fast Timing Detectors for ATLAS WHO? UTA (Brandt), Alberta, Louvain, FNAL WHY? Background Rejection Ex, Two protons from one interaction and two b-jets from another How? Use timing to measure vertex and compare to central tracking vertex photon How Fast? 10 picoseconds (light travels 3mm in 10 psec!) MCP-PMT Pedro Duarte (M.S.) Shane SpiveyIan Howley
Spread in timing as f() since n() 60 psec Simulation by Joaquin Noyola (UG) other studies by UG Chance Harenza+ Alek Malcolm Fused Silica Bars • 9 cm bars • Some converted to mini-bars
MCP-PMT Operation photon Faceplate Photocathode Photoelectron DV ~ 200V Dual MCP DV ~ 2000V Gain ~ 106 DV ~ 200V Anode
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)
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()
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
Good Event 5 ns/major division
Online Screen Capture one histo is 10 ps per bin others are 20 ps delta time between channels
QUARTIC Long Bar Resolution Dt 56.6/1.4=40 ps/bar including CFD!
Undergraduate Student Research Opportunities Several aspects of fast timing project are short of (wo)manpower: • Helping to setup and operate laser test stand • Operating/improving ray tracing simulation • Commercial ray tracing program to aid in simulation • HEP detector simulation GEANT4 • Test beam data analysis Experience with C++ required for some but not all of the projects Some funding available (results oriented)
Laser Test Stand Argonne National Lab setup Use Hamamatsu picosecond laser to measure timing of PMT, electronics
QUARTIC Bar Length Studies 15mm bar/75 mm lightguide 20 ps 90mm bar 40 ps 40 ps
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