PHYS 3446 Lecture #1 Monday Aug 25, 2008 Dr. Andrew Brandt 1.Syllabus and Introduction 2.HEP...
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Transcript of PHYS 3446 Lecture #1 Monday Aug 25, 2008 Dr. Andrew Brandt 1.Syllabus and Introduction 2.HEP...
PHYS 3446 Lecture #1
Monday Aug 25, 2008Dr. Andrew Brandt
1. Syllabus and Introduction2. 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
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 STRONGLYSTRONGLY 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 STRONGLYSTRONGLY 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.
Structure of Matter
cm
Matter
10-9m
Molecule
10-10m 10-14m
Atom Nucleus
Atomic Physics
NuclearPhysics
High energy means small distances
Nano-Science/Chemistry10-15m
u
<10-18m
QuarkBaryon
Electron
<10-19mprotons, neutrons,
mesons, etc.
top, bottom,
charm, strange,up, down
High Energy Physics
(Hadron)
(Lepton)
Periodic Table
All atoms are madeof protons, neutronsand electrons
Helium Neon
u
du u
d d
Proton NeutronElectron
Gluons hold quarks togetherPhotons hold atoms together
What is High Energy Physics? Matter/Forces at the most fundamental level.
Great progress! The “STANDARD MODELSTANDARD 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: pp, pp, e+e-, ep
– Fixed Target Experiments: Particles on a target
– Type of accelerator depends on research goals
Fermilab Tevatron and CERN LHC• 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
Chicago
Tevatron p
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 – 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
1500 physicists130 institutions30 countries
5000 physicists250 institutions60 countries
The International Linear Collider
33km=
21mi
European Design500 GeV (800 GeV)
47 km
=29 mi
US Design500 GeV (1 TeV)
• Long~ linear electron-position colliders
• Optimistically 15 years from now
• Takes 10 years to build an accelerator and the detectors
Particle Identification
InteractionPoint
electron
photon
jet
muonneutrino -- or any non-interacting particle missing transverse momentum
Ä B
Scintillating FiberSilicon Tracking
Charged Particle Tracks
Calorimeter (dense)
EM hadronic
Energy
Wire Chambers
Mag
net
Muon Tracks
We know x,y starting momenta is zero, butalong the z axis it is not, so many of our measurements are in the xy plane, or transverse
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 0.5x1015 (500,000,000,000,000) bytes per year (0.5 PetaBytes).
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).
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 chargeconfinement - not usual 1/r2
Standard Model has been very successfulbut has too many parameters, does notexplain origin of mass. Continue to probeand attempt to extend model.
High Energy Physics Training + Jobs
EXPERIENCE:1) Problem solving 2) Data analysis3) Detector construction4) State-of-the-art high speed electronics 5) Computing (C++, Python, Linux, etc.)6) Presentation 7) Travel
JOBS:1) Post-docs/faculty positions2) High-tech industry3) Computer programming and development4) 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)
• 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.)
Detector ConstructionDetector ConstructionDetector ConstructionDetector ConstructionAt 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.
One of the DØ Forward Proton Detectors builtat UTA and installed in the Tevatron tunnel
Tevatron: World’s Highest Energy ColliderFermilab
DØ
High-tech fan
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
Central Exclusive Higgs Production pp p H p : 3-10 fb
beam
p’
p’roman pots roman pots
dipole
dipole
22 )''( ppppM H
E.g. V. Khoze et alM. 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
Hgap gap
b
b -jet
-jet
p p
Arnab Pal
n=1 n>>1
Cerenkov Effect
Use this property of prompt radiation to develop a fasttiming counter
particle
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!)
phot
on
Pedro Duarte (M.S.)Shane SpiveyIan Howley
proton
MCP-PM
T
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 UGChance Harenza+Alek Malcolm
MCP-PMT Operation
Faceplate
Photocathode
Dual MCP
Anode
Gain ~ 106
Photoelectron V ~ 200V
V ~ 200V
V ~ 2000V
photon
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 resolution2. Jitter in PMT's3. 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
Undergraduate Student Research Opportunities
Several aspects of fast timing project are short of (wo)manpower:
1) Helping to setup and operate laser test stand2) Operating/improving ray tracing simulation3) Commercial ray tracing program to aid in simulation 4) HEP detector simulation GEANT45) 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 Hamamatsupicosecond laserto measure timingof PMT, electronics
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