PHYS 3446
Lecture #1
Monday Aug 25, 2008
Dr. Andrew Brandt
1. Syllabus and Introduction
2. 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
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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%
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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
Matter
Molecule
Atom
Nucleus
Baryon
Quark
(Hadron)
u
cm
10-14m
10-9m
10-10m
Nano-Science/Chemistry
Atomic Physics
Nuclear
Physics
10-15m
<10-19m
top
protons, neutrons,
, bottom,
mesons, etc.
charm, strange,
p,W,L...
up, down
Electron
(Lepton)
<10-18m
High energy means small distances
High Energy Physics
Helium
Periodic Table
Neon
All atoms are made
of protons, neutrons
and electrons
u u
d
u
d d
Neutron
Proton
Gluons hold quarks together
Photons hold atoms together
Electron
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
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
Highest Energy protonproton 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
Chicago

1500 physicists
130 institutions
30 countries
CDF
•
p
Tevatron
DØ
`p
Fermilab: http://www.fnal.gov/ ; DØ: http://www-d0.fnal.gov/
5000 physicists
250 institutions
60 countries
CERN: http://www.cern.ch/ ; ATLAS: http://atlas.web.cern.ch/
The International Linear Collider
European Design
500 GeV (800 GeV)
• Long~ linear
electron-position
colliders
33km=
• Optimistically 15
47 km
21mi
years from now
• Takes 10 years to
=29 mi
build an accelerator
and the detectors
US Design
500 GeV (1 TeV)
Particle Identification
Energy
Scintillating Fiber
Silicon Tracking
Calorimeter (dense)
Interaction
Point
Ä B
EM
Muon Tracks
Magnet
Charged Particle Tracks
hadronic
electron
photon
Wire Chambers
jet
neutrino -- or any non-interacting particle
missing transverse momentum
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
muon
DØ Detector
ATLAS Detector
30’
50’
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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).
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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
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.
The strong force is different
from E+M and gravity!
new property, color charge
confinement - not usual 1/r2
• Current list of elementary
(i.e. indivisible) particles
• Antiparticles have opposite
charge, same mass
UTA and Particle
Physics
Fermilab/Chicago
CERN/Geneva
Building Detectors at UTA
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
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
• Dipole Spectrometer
• inside the beam ring
in the horizontal plane
• use dipole magnet
(bends beam)
• Quadrupole Spectrometers
• surround the beam: up, down, in, out
• use quadrupole magnets (focus 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
FP420 Overview
FP420: Particle physics R&D collaboration that
proposes to use double proton tagging at 420m
as a means to discover new physics
NEW
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…
b -jet
gap
p
gap
H
p
b -jet
beam
h
Idea: Measure the Missing
mass from the protons
M H2  ( p  p  p' p' )2
dipole
M = O(1.0 - 2.0) GeV
dipole
p’
roman pots
roman pots
p’
Arnab Pal
Cerenkov Effect
n=1
n>>1
particle
Use this property of prompt radiation to develop a fast
timing counter
Fast Timing Detectors for ATLAS
WHO?
WHY?
UTA (Brandt), Alberta, Louvain, FNAL
Background Rejection
Ex, Two protons from one interaction and two b-jets from another
proton
Use timing to measure
vertex and compare to
central tracking vertex
How?
How Fast?
10 picoseconds (light travels 3mm in 10 psec!)
Pedro Duarte (M.S.)
Shane Spivey
Ian Howley
Fused Silica Bars
• 9 cm bars
• Some converted to mini-bars
Simulation by
Joaquin Noyola (UG)
other studies by UG
Chance Harenza+
Alek Malcolm
60 psec
Spread in
timing as f()
since n()
MCP-PMT Operation
photon
Faceplate
Photocathode
Photoelectron
Dual MCP
V ~ 2000V
Gain ~ 106
Anode
V ~ 200V
V ~ 200V
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()
FP420 Timing Setup
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:
1)
2)
3)
4)
5)
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