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PHYS 3446 Lecture #1

Wednesday January 18, 2012 Dr. Andrew Brandt. PHYS 3446 Lecture #1. Syllabus and Introduction High Energy Physics at UTA. Please turn off your cell-phones, pagers and laptops in class. Thanks to Dr. Yu for developing initial electronic version of this class.

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PHYS 3446 Lecture #1

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  1. Wednesday January 18, 2012 Dr. Andrew Brandt PHYS 3446 Lecture #1 • Syllabus and Introduction • High Energy Physics at UTA Please turn off your cell-phones, pagers and laptops in class Thanks to Dr. Yu for developing initial electronic version of this class http://www-hep.uta.edu/~brandta/teaching/sp2012/teaching.html

  2. My Background+Research B.S. Physics and Economics College of William&Mary 1985 PH.D. UCLA/CERN High Energy Physics 1992 (UA8 Experiment-discovered hard diffraction) 1992-1999 Post-doc and Lab Scientist at Fermi National Accelerator Laboratory -1997 Presidential Award for contributions to diffraction -Proposed and built (with collaborators from Brazil) DØ Forward Proton Detector -Physics Convenor -Trigger Meister 1999 Joined UTA as an Assistant Professor 2004 promoted to Associate Professor 2010 promoted to Full Professor - Funding from NSF, DOE, and Texas approaching 10M$ as PI or Co-PI PHYS 1444-004, Dr. Andrew Brandt

  3. My Main Research Interests • High Energy Physics (aka Particle Physics) • Physics with Forward Proton Detectors (detect protons scattered at small angles) • Fast timing detectors (How fast? Really really fast!) http://www.youtube.com/watch?v=By1JQFxfLMM&feature=related • Triggering (selecting the events to write to tape): at ATLAS must choose most interesting 300 out of up to 40,000,000 events/sec • Higgs Discovery • Weapons of Mass Destruction (detection of) PHYS 1444-004, Dr. Andrew Brandt

  4. Grading • Only test is a Midterm: 25% • No Final • Test will be curved if necessary • No makeup tests • Homework: 20% (no late homework) • Lab score: 25% (details soon) • Project: 20% (a look at early ATLAS data or a report/presentation on important events in particle physics?) • Pop Quizzes: 10%

  5. 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

  6. Physics History • Classical Physics: forces, motion, work, energy, E&M, (Galileo, Newton, Faraday, Maxwell) • In modern physics (Einstein, Planck, Bohr) we covered relativity, models for the atom, some statistical mechanics, and finished with a bit of discussion about the nucleus and binding energy circa 1930 when the neutron was discovered • What’s new since 1930?

  7. Physics History • I’m going to have to respectfully disagree with you Leonard… • 1937 muon discovered (who ordered that?) • With advent of particle accelerators came particle zoo • There was a need to classify all the new particles being discovered and try to understand the underlying forces and theory

  8. Course Material • Nuclear Physics • Models of atom • Cross sections • Radiation • High Energy Experiment • Energy deposition in matter • Particle detector techniques • Accelerators • HEP Phenomenology • Elementary particle interactions • Symmetries • The Standard Model • Beyond the Standard Model

  9. 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.

  10. 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

  11. 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

  12. 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

  13. 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

  14. Chicago  CDF p DØ Tevatron p Fermilab Tevatron and CERN LHC • Highest Energy (proton-proton) collider since fall 2009 • 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 7 TeV collisions • 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/

  15. 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 Dr.White is co-spokesman of SiD detector

  16. 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 neutrino (or any non-interacting particle missing transverse momentum) muon We know x,ystartingmomenta is zero, but along the z axis it is not, so many of our measurements are in the xy plane, or transverse

  17. 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 • Recors 200 -300 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).

  18. 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

  19. UTA and Particle Physics Fermilab/Chicago CERN/Geneva ILC? U.S.?

  20. Building Detectors at UTA

  21. 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 High Energy Physics Training + Jobs

  22. 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 to measure the momentum and scattering angle of the proton • 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. 2006)

  23. 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.

  24. Tevatron: World’s 2ndHighest Energy Collider Fermilab DØ High-tech fan One of the DØ Forward Proton Detectors built at UTA and installed in the Tevatron tunnel

  25. Elastic Scattering Cross Section (FPD)

  26. Single Diffractive Cross Section (FPD) Arnab Pal (UTA PhD student)

  27. ATLAS Forward Protons: A (10) Picosecond Window on the Higgs Boson Andrew Brandt, University of Texas at Arlington A picosecond is a trillionth of a second. This door opens ~once a second, if it opened every 10 picoseconds it would open a hundred billion times in one second (100,000,000) Light can travel 7 times around the earth in one second but can only travel 3 mm in 10 psec Yes, I know it’s a door, not a window! Andrew Brandt SLAC Seminar

  28. Central Exclusive Higgs AFP concept: adds new ATLAS sub-detectors at 220 and 420 m upstream and downstream of central detector to precisely measure the scattered protons to complement ATLAS discovery program. These detectors are designed to run at a luminosity of 1034 cm-2s-1 and operate with standard optics (need high luminosity for discovery physics) H 220 m 420 m beam LHC magnets You might ask: “Why build a 14 TeV collider and have 99% of your energy taken away by the protons, are you guys crazy or what??” p’ p’ AFP Detector The answer is “or what”!—ATLAS is routinely losing energy down the beam pipe, we just measure it accurately!!! Note: the quest for optimal S/B can take you to interesting places: Ex. The leading discovery channel for light SM Higgs, H , has a branching ratio of 0.002!

  29. particle Cerenkov Effect n=1 n>>1 Use this property of prompt radiation to develop a fast timing counter

  30. Micro-Channel Plate Photomultiplier Tube(MCP-PMT) e- + + photon Faceplate Photocathode Photoelectron DV ~ 200V Dual MCP DV ~ 2000V Gain ~ 106 MCP-PMT DV ~ 200V Anode

  31. Ultra-fast Timing Issues Time resolution for the full detector system: 1. Intrinsec detector time resolution 2. Jitter in PMT's 3. Electronics (AMP/CFD/TDC) 4. Reference Timing • 3 mm =10 ps • Radiation hardness of all components of system • Lifetime and recovery time of tube • Backgrounds • Multiple proton timing Andrew Brandt SLAC Seminar

  32. Laser Tests Study properties of MCP-PMT’s: • How does timing depend on gain and number of pe’s • What is maximum rate? How does this depend on various quantities? 3) Establish minimum gain to achieve timing goals of our detector given expected number of pe’s (~10). Evaluate different electronics choices at the working point of our detector 4) Eventually lifetime tests ***Ongoing laser tests very useful in developing the fastest time of flight detector ever deployed in a collider experiment

  33. PTF beam splitter LeCroy Wavemaster 6 GHz Oscilloscope mirror Picosecond Test Facility featuring initial Undergraduate Laser Gang (UGLG) Undergraduate Laser Youths? (UGLY) filter MCP-PMT lenses laser Hamamatsu PLP-10 Laser Power Supply Laser Box Andrew Brandt SLAC Seminar

  34. Timing vs Gain for 10 m Tube Measured with reference tube using CFD’s and x100 mini-circuits amps, with 10 pe’s can operate at ~5E4 Gain (critical for reducing rate and lifetime issues) With further optimization have obtained <25 ps resolution for 10 pe’s.

  35. Timing vs. Number of PE’s No dependence of timing on gain if sufficient amplification!

  36. Aside: Measuring Speed of EM Waves • We noted that ground plane oscillations on reference tube were picked up by second tube • Used this to do a 3% measurement of speed of light (Kelly Kjornes) Moving 2nd tube 2 feet from reference tube shifts pick-up oscillation pattern by 2.05 ns

  37. New Multi-Channel Laser Setup Andrew Brandt SLAC Seminar

  38. Pre-lecture Conclusions • Nuclear and Particle picks up where Modern Physics left off • One of the current frontiers of physics is high energy or particle physics: very interesting (I think!) • Nobel Prize possibilities • Other interesting areas of physics at UTA include nano-bio physics, astrophysics, nano-magnetism, etc.

  39. 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 in particle physics

  40. Why Do Physics? Exp.{ Theory { • To understand nature through experimental observations and measurements (Research) • Establish limited number of fundamental laws, usually with mathematical expressions • Explain and predict nature • Theory and Experiment work hand-in-hand • Theory generally works under restricted conditions • Discrepancies between experimental measurements and theory are good for improvement of theory • Modern society is based on technology derived from detailed understanding of physics PHYS 1444-004, Dr. Andrew Brandt

  41. Why Do Physics Part Deux http://www.aps.org/publications/apsnews/200911/physicsmajors.cfm 2008/2009 Graduates 1.7% unemployment While engineering starting salaries are typically higher than physicists, mid-career salaries are virtually identical 101k$ for engineering 99k$ for physics PHYS 1444-004, Dr. Andrew Brandt

  42. What Do Physicists Do? PHYS 1444-004, Dr. Andrew Brandt

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