1. A Taste of Things to Come
Welcome to Physics Honours!
W. A. Horowitz
University of Cape Town
February 11th, 2011
1/13/2019
UCT Honours

2. Four Fundamental Forces
Electromagnetism
Gravity
starchild.gsfc.nasa.gov
John Maarschalk, travelblog.portfoliocollection.com
Weak
Strong
lhs.lps.org/staff/sputnam/chem_notes/tritium_decay.gif
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3. Strong compared to E&M - + Electromagnetism Strong Electric charge (+)
electrons
Carriers: photons
Field theory:
Quantum electro-dynamics (QED)
Strong
Color charge (r, g, b)
quarks
Carriers: gluons
Field theory:
Quantum chromo-dynamics (QCD) -
Hydrogen
Look Inside +
Proton
nobelprize.org
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4. High Energy Nuclear Physics is High Energy Gluon Physics
Nucleus looks different at high E
Nucleus becomes fatter with Energy E
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5. Nucleus as a Function of Energy
Measure the nuclear shape in e + A collisions E
X-scn: Fourier Transform of Shape
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6. What about Heavy Ion Physics?
Measure many-body physics of strong force
Test & understand theory of many-body non-Abelian fields
Unique as compared to strongly coupled Abelian problems
Long Range Plan, 2008
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7. Heavy Ion Collisions Collider machines: RHIC, LHC
Relativistic Heavy Ion Collider
Large Hadron Collider
1/13/2019
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8. Big Bang vs. Little Bang t = - ¥ t = 0 t = 1 fm/c t = 3 fm/c
ALICE Collaboration
t = - ¥
t = 0
t = 1 fm/c
t = 3 fm/c
t = 4 fm/c
t = + ¥
Initial State
Initial Overlap
Thermalization
QGP
Hadronization
Hadron Gas
1/13/2019
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9. Orders of Magnitude Units: MeV, GeV
At RHIC, nuclei acc. to 100 GeV per nucleon
Energy of collision ~ two mosquitoes colliding
Chaisson and McMillan,
Astronomy Today (1993)
Tc ~ LQCD ~ 200 MeV
Temp. at RHIC ~ 10,000 times hotter than the core of the sun (15,000,000 Kelvin)
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10. Experiments RHIC LHC BRAHMS PHENIX PHOBOS STAR ALICE ATLAS CMS LHCb
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11. Evolution of a HI Collision
T Hirano, Colliding Nuclei from AMeV to ATeV
STAR
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12. Why High-pT Jets? Tomography in medicine
One can learn a lot from a single probe…
and even more with multiple probes
SPECT-CT Scan uses internal g photons and external X-rays
PET Scan
1/13/2019
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13. Tomography in QGP Requires well-controlled theory of:
production of rare, high-pT probes
g, u, d, s, c, b
in-medium E-loss
hadronization
Requires precision measurements of decay fragments pT f
, g, e-
Invert attenuation pattern => measure medium properties
1/13/2019
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14. QGP Energy Loss Learn about E-loss mechanism Most direct probe of DOF
AdS/CFT Picture
pQCD Picture
1/13/2019
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15. Compare to Data Naively: if medium has no effect, then RAA = 1
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16. LHC RcAA(pT)/RbAA(pT) Prediction
Zoo of c and b Predictions:
WAH, M. Gyulassy, PLB666 (2008)
Taking the ratio cancels most normalization differences seen previously
pQCD ratio asymptotically approaches 1, and more slowly so for increased quenching (until quenching saturates)
AdS/CFT ratio is flat and many times smaller than pQCD at only moderate pT
WAH, M. Gyulassy, PLB666 (2008)
1/13/2019
UT Colloquium

17. Research interests: Gary Tupper
Particle physics
Quantum field theory
String theory & braneworld
General relativity, Cosmology, Dark Matter & Dark Energy
Unification of dark matter and dark energy: The Inhomogeneous Chaplygin gas. Neven Bilic, Gary B. Tupper, Raoul D. Viollier, (Cape Town U.) . Nov pp. Published in Phys.Lett.B535:17-21, e-Print: astro-ph/
TOPCITE = 250+ Cited 424 times
Transport modelling in industrial mills
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18. Most of the stuff in the universe is nonluminous
Overall picture today:
Particle Dark Matter?
Cosmological Constant Dark Energy?
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19. Tumbling Mills Minerals industry (gold, platinum, copper, etc …)
1st stage of above ground mineral beneficiation
Size reduction
Expose valuable mineral
15% of power consumption in SA
60% of operation cost
Models are empirical
Cannot extrapolate
Mill specific
Ore specific
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20. PUBLICATIONS: See http://www.slac.stanford.edu/spires/hep/
PhD STUDENTS (UCT) 2011: Sebastian Bodenstein (1st year), Preshin Moodley (1st year), and Yingwen Zhang (2nd year). Fellowships from RSA National Institute for Theoretical Physics (NITheP).
INTERNATIONAL COLLABORATIONS: with colleagues from the universities of Mainz (Germany), Valencia (Spain), Mexico, Chile, and Argentina. Graduate students participating and visiting these institutions on a yearly basis.
SUMMER SCHOOL, ICTP (TRIESTE): Graduate students attending yearly summer school at ICTP (International Centre for Theoretical Physics) thanks to Federation Arrangement.
PUBLICATIONS: See
Under author C DOMINGUEZ.
Emer. Prof. Cesareo A. Dominguez, UCT & SUN
RESEARCH: Quantum Chromodynamics (QCD), in particular determination of the fundamental QCD parameters: quark-gluon coupling and quark masses. Non-perturbative effects in QCD due to confinement. QCD sum rules. QCD at finite temperature and density, and connection with quark-gluon plasma studies, quark and gluon deconfinement, etc. Relation to experiments at BNL and LHC. Quantum Electrodynamics (QED): nonlinear effects due to quantum fluctuations in the QED vacuum. Prediction of new phenomena, and design of experiments to measure them, e.g. neutron scattering off nuclei, and high intensity laser experiments.
1/13/2019
UCT Honours

21. Monte Carlo Modeling Model of proton therapy beam line
[Dr. Steve Peterson]
Model of proton therapy beam line
Positron path
Calculating positron range
Designing a 3-stage Compton camera
1/13/2019
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22. Image Reconstruction
[Dr. Steve Peterson]
Capturing scattered prompt gammas from proton beam in 3-stage Compton camera
Overlap of back-projected cones to reproduce source
1/13/2019
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23. Let’s Eat!
1/13/2019
UCT Honours