A Festschrift and Conference on
THE GOLDEN AGE OF PARTICLE
PHYSICS AND ITS LEGACY
Boston University
In honour of Lawrence Sulak
From Physics Graduate Student in the '70s
to Observing Supernovae Today
Charling Tao
Centre de Physique des Particules de Marseille
IN2P3/CNRS and U. Méditerranée
ITA NAOC Beijing
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Foreword
We would particularly be interested in hearing your
thoughts on
``The life of a physics graduate student in the '70's".
Aie !!Yaie!!! I am not a sociologist!!!!
wish I had Tom Wolfe’ s talent
for a « I am Charlotte Simmons » speech!
:-*
Perhaps I could talk about my present work
on SN and Dark Energy. Would be easier for me…
OK! The title of your talk is:
From Physics Graduate Student in the '70s
to Observing Supernovae Today
Charling Tao, Sulak Festschrift, Oct 21-22,2005
My graduate years: 1975-1979
Harvard U.
My Thesis (R. Wilson) :
The Structure and Formation of Hadrons: An Experiment with a
Muon Beam of 219 GeV on a Hydrogen Target.
Test of QCD:logarithmic breaking of scale invariance
Frontiers of physics at the time
Charling Tao, Sulak Festschrift, Oct 21-22,2005
My Harvard graduate school
environment
:-)
Adviser: Richard Wilson, (+ A.L. Sessoms + T. Loomis)
Teachers:
Sidney Coleman : QFT (John Lo Secco)
Shelly Glashow: Group Theory
Alvaro de Rujula: Weak Interactions
Steven Weinberg: General Relativity and Cosmology
Carlo Rubbia: Particle Physics
Howard Georgi,…
Lots of other people around at the time: N. Ramsey, P. Martin,
F.Pipkin, K. Strauch, Ed Witten, D. Politzer, G. t’Hooft, P. MacIntyre,
W. Skocpol, Tinkham, ….
Students at the time present today ; Witold Kozanecki, Jim Strait,
Michael
Bruce Cortez,
Ian Affleck, Dave Hannah, Wesley Smith, …
Charling Tao,Levi,
Sulak Festschrift,
Oct 21-22,2005
Harvard PhD 1979, 10/20 in particle physics
•AFFLECK, IAN KEITH,. Some Results on Vacuum Decay. (Coleman)
•ALVAREZ, ORLANDO, Conformal Invariance in Quantum Field Theory.
(Weinberg)
•DAVIS, SAMUEL, Predictions and Limitations of Perturbative QCD.
(Georgi)
•DE LUCCIA, FRANK JOSEPH, The Fate of the False Vacuum: Induced
Decay and Gravitational Effects on Spontaneous Decay. (Coleman)
•RICH, JAMES ARNOLD, Trimuon Production by High Energy Neutrinos.
(Rubbia)
•ROCEK, MARTIN,. Aspects of Spontaneous Symmetry Breakdown of
Supersymmetry. (Wu)
•SHEIMAN, JOHATHAN LEWIS, Topics in the Theory of
Leptoproduction. (Georgi)
•SMOLIN, LEE, Studies in Quantum Gravity. (Coleman)
•SOBELMAN, GERALD EDWARD, Asymptotic Estimates and Borel
Resummation for a Doubly Anharmonic Oscillator. (Coleman)
•TAO, CHARLING SUN, The Structure and Formation of Hadrons: An
Experiment with a Muon Beam of 219 GeV on a Hydrogen Target. (Wilson)
Charling Tao, Sulak Festschrift, Oct 21-22,2005
1975 class: 32 graduate students
1 female and only 1 other 6 years before!
:-*
Year after : 2 female graduate students
Since then, at least 1 graduating /year
Not great!
But not 0
Thank you Larry
(and Beth)
for the conscious effort to bring more women in science
Charling Tao, Sulak Festschrift, Oct 21-22,2005
What did I learn from Graduate school
in the 70’s?
The Feynman Problem Solving Algorithm:
1) Write down the problem.
2) Think very hard.
3) Write down the solution.
:-)
Charling Tao, Sulak Festschrift, Oct 21-22,2005
What did I learn from Graduate school
in the 70’s?
- A lot of physics, and detector building, of course,
- need to work hard
But more important is the Scientific Method
When faced with any problem:
Don’t be afraid, ask questions
Example of Larry :
an ever young, enthusiastic and
curious mind
And do not forget to be socially conscious and active
Charling Tao, Sulak Festschrift, Oct 21-22,2005
What is Physics?
Physics is an art,
the art of unveiling
the invisible
Charling Tao, Sulak Festschrift, Oct 21-22,2005
What is Physics?
Physics is a language,
a « universal » human language that
translates the « real » world
into something « understandable »
Charling Tao, Sulak Festschrift, Oct 21-22,2005
What did I learn from Graduate school
in the 70’s?
There are many ways to do physics
and understand Nature
Reductionnist / Emergent
Theoretical / experimental/ phenomenology
Different fields
Choose one path in graduate school
and learn the techniques
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Why did I do a thesis on tests of QCD in
Deep Inelastic Muon Scattering in 1975 ?
And why SNIa search
today?
The Larry Sulak/Harvard Spirit
Frontiers of Physics
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Charling Tao, Sulak Festschrift, Oct 21-22,2005
1970’s frontiers of physics?
ne
nm
nt
g
e
m
t
g
t
Z0 , W+ ,W- weak
leptons
u
c
quarks
d
s
3 fermion families
Fundamental particles
Charling Tao, Sulak Festschrift, Oct 21-22,2005
b
‘G’
strong
electromagnetic
‘H0’
gravitation
Vector bosons of interactions
interactions
1970’s frontiers of physics?
ne
nm
nt
g
e
m
t
g
t
Z0 , W+ ,W- weak
leptons
u
c
quarks
d
s
3 fermion families
Fundamental particles
b
‘G’
strong
electromagnetic
‘H0’
gravitation
Vector bosons of interactions
interactions
Completing our knowledge of
Fundamental Particle constituents of matter
Charling Tao, Sulak Festschrift, Oct 21-22,2005
and Fundamental interactions
The Golden Age of particle physics
In 1950-s : advent of particle accelerators
beams of electrons or protons with high kinetic energy.
the 4.5-inch model cyclotron built
byTao,
Lawrence
andOct
Livingston.
Charling
Sulak Festschrift,
21-22,2005
Oct. 20, 1955: discovery
of the antiproton
Can plan the experiments and repeat them!
 Particle physics second name
High energy physics
 many new particles
 new classification: leptons, mesons, baryons
« the eightfold way » Gell-man & Neeman
Nobel Prize in Physics 1969
 Leptons and quarks
Charling Tao, Sulak Festschrift, Oct 21-22,2005
1970’s frontiers of physics?
Towards the Standard Model of the Fundamental
interactions SU(3) x SU(2) x U(1)
1973
- Asymptotic freedom: Quantum Chromodynamics (QCD)
- Unification of weak and electromagnetic interactions
(discovery of Neutral currents)
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Sheldon Glashow Steven Weinberg
Abdus Salam
1970’s frontiers of physics?
Completing the particle constituent table
~1975
- J/Psi discovered (S.Ting et al., Richter et al.)
evidence for charm, postulated in 1973 (GIM)
- tau lepton (M. Perl et al.): Indication for a third family
Completing the third family
1977: beauty (Lederman et al.)
1995: top quark discovery
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Nobel for v beams
and vm
1980’s: Triumph of the Standard Model
• Unification electromagnetism and weak interaction
Prediction of W, Z observed at CERN UA1/2
experiments (C. Rubbia et al….)
First W
Charling Tao, Sulak Festschrift, Oct 21-22,2005
First Z
Where was
?
IMB
Proton
decay
+
Neutrino
Osc.
+
SN1987A
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Next frontiers ?
Beyond the SM of particle physics
First hint with neutrino masses ?
L. Wolfenstein
First hint of neutrino masses:
Charling Tao, Sulak Festschrift, Oct 21-22,2005
n
Solar neutrino problem
A pioneering experiment…
1970
R. Davis
600 tons of C2Cl4
37Ar + ene + 37Cl
Homestake
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Probing the Universe with neutrinos
SuperKamiokande neutrino
image of the Sun
Pioneering Involvement in neutrino telescopes
DUMAND started in 1976
IMB/ SuperK in 1978/1979
Charling Tao, Sulak Festschrift, Oct 21-22,2005
P.Coyle
12 lines (900 PMTs)
25 storeys / line
3 PMTs/storey
Horizontal layout
2500 m
40 km to
shore
storey
14.5 m
350 m
m
The 70
ANTARES
underwater detector
Charling Tao, Sulak
Festschrift,
Oct 21-22,2005
in the
Mediterranean
sea
100 m Junction
box
Readout cables
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Next frontiers
Quantum theory
• SUSY
• Superstrings
• Quantum Gravity
New particles?

Extra dimensions?
Negative energies?
Space topologies?
Violation of Lorentz invariance?
Cosmology
• Dark Matter
• Dark Energy
Is the cosmological
constant, constant?
What is its relationship
with quantum vacuum
fluctuations?
Accelerator physics is fundamental
but new physics hints could be coming
from « astro » and « cosmo » data
Charling Tao, Sulak Festschrift, Oct 21-22,2005
(Back to Cosmic Ray physics!)
A mysterious Universe
WMAP
Position 1st peak
WT =1.02 +/- 0.02
Flat universe
Ratio (2/1) peaks
WB =0.046 +/- 0.006
Definition: W=r/rc (rc=10-29 g/cm3)
Ordinary Matter: 4%
CMB, + SN, clusters, galaxies redshift surveys,
Weak Lensing, …

Concordant LCDM model with
Cold Dark Matter and Cosmological constant
Charling Tao, Sulak Festschrift, Oct 21-22,2005
2/3
Dark
Energy
1/3
Dark
Matter
Why SNIa search today?
Mystery of the Dark Universe !
(Michael Levi)
• What expertise do we bring to the field?
Handling of large sample of data
• Control of systematics: from a 2s measurement to a credible
result
• SNLS is one step
• Nearby supernovae program VERY important!
• SNAP/JDEM 1% measurement
Today’s Frontiers of physics
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Different standardisation methods
Before: mB
After, eg, stretch correction:
mBcor = mB – a (s-1)
Different standardisation methods : stretch (SCP), MLC2k2 (HiZ), Dm15, ...
Charling Tao, Sulak Festschrift, Oct 21-22,2005
SN Ia in 2004:
A selection by Riess et al, astro-ph 0402512
16 new SN Ia with HST (GOOD ACS Treasury
program)
6 / 7 existing with z >1.25
+ Compilation (Tonry et al. 2003): 172 with changes from…
* Knop et al, 2003, SCP : 11 new 0.4 < z < 0.85
reanalysis of 1999, Perlmutter et al.
* 15 / original 42 excluded/inaccurate colour measurements and uncertain classification
* 6 /42 and 5/11: fail « strict SNIA » sample cut
* Barris et al, 2003, HZT: 22 new: varying degrees of completeness on
photometry and spectroscopy records
* Blakesly et al, 2003 : 2 with ACS on HST
+ Low z : 0.01 < z < 0.15
• Calan-Tololo (Hamuy et al., 1996) : 29
• CfA I (Riess et al. 1999): 22
• CfA II (Jha et al, 2004b): 44
Charling Tao, Sulak Festschrift, Oct 21-22,2005
A Dm=0.27 shift of low z data
Shift z <0.15 data by Dm= 0.27
Use Kosmoshow by A. Tilquin!
 Wm= 0.43 +/-0.2 and WL= 0 +/-0.34
No need for L
But Universe is not flat!
Charling Tao, Sulak Festschrift, Oct 21-22,2005
The CFHT
Legacy Survey
Supernovæ Program
SNLS
http://snls.in2p3.fr/people/snls-members.html
Charling Tao, Sulak Festschrift, Oct 21-22,2005
The CFHT
Legacy Survey Supernovæ Program
Canada and France
(CPPM)
Extra collaborators :
VLT: ESO, Portugal, Sweden, UK.
Keck: US.
Gemini: UK, US.
Charling Tao, Sulak Festschrift, Oct 21-22,2005
SNLS First year results
with 71 SNIa
astroph/0510447 to appear in
A&A
with CFHTLS and VLT, Gemini, Keck for
spectroscopy
At the end 700 SNIa!
Charling Tao, Sulak Festschrift, Oct 21-22,2005
First results: Cosmological parameter
fits
•
SNLS first year contours, combined with Baryon oscillation results
(Eisenstein et al 2005)
Charling Tao, Sulak Festschrift, Oct 21-22,2005
First results: numbers
• For a flat LCDM cosmology
WM=0.263 +- 0.042 (stat) +- 0.032 (syst)
• For a flat WM,w cosmology,
– Combined with Baryonic acoutic oscillation (Eisenstein 2005)
WM= 0.271 +- 0.021 (stat) +- 0.007 (syst)
w = -1.023 +- 0.090 (stat) +- 0.054 (syst)
No surprise result!
But better control of systematics
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Need for multiprobes to constraint w
Ch. Yèche, A.Ealet, A. Réfrégier, C. Tao, A. Tilquin, J.-M. Virey, and D. Yvon.
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Stronger constraints thanks to correlations
 For Wm-w0 and for w0-wa, we observe
 Actually we have 9-dim correlations,
orthogonal correlations between (CMB-WL) we gain more than the simple 2-dim
and SNIa
overlap!
 It allows to break the degeneracies.
 We use the full correlation matrix.
40 21-22,2005
Charling Tao, Sulak Festschrift, Oct
Gravitationnal arcs
Indication of Dark
Matter in the
Universe
Charling Tao, Sulak Festschrift, Oct 21-22,2005
A. Réfrégier
Weak Lensing effects
Distorsion of background images by foreground matter
Without lensing
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Lensing effect
A. Réfrégier
Deformation matrix:

“Weak Lensing”
i
 2
ij =
=  dz g ( z )
 j
 i  j
Direct measure of mass distribution in the Universe
Other methods measure light distribution
Principles of “Weak Lensing”
Deformation matrix:
-g 2 
i 1 -  - g 1

ij =
= 
1- + g 2 
 j  - g 2
=
Convergence:

 crit
= 
1
2
2
g 1 = 12 (11 -  2 2 ) ; g 2 = 1 2
Shear
Critical surface density
 crit
c 2 Dos
=
4G Dol Dls
Weak lensing:  << 1 (linear approximation)
Measure shear g and solve for projected mass 
Charling Tao, Sulak Festschrift, Oct 21-22,2005
“Shear” measurement
Quadrupole Moments :
 
Qij =  d x xi x j w( x ) I ( x )
2
Q11 - Q22
2Q12
1 =
, 2 =
Q11 + Q22
Q11 + Q22
Ellipticity:
2
Shear:
1
Relation:
g2 
1 -  - g 1

ij = 
1- + g 1 
 g2
 i = Pg g i
Baryon acoustic oscillations
from SDSS LRGs 0.2 < z < 0.5
Acoustic series in P(k)
becomes a single peak in x(r)!
Pure CDM model has no peak.
CDM with baryons is a good fit:
c2 = 16.1 with 17 dof.
Pure CDM rejected at Dc2 = 11.7
Warning:
Correlated
Charling
Tao, Sulak Festschrift, Oct 21-22,2005
Error Bars
The Golden age of Cosmology
HST
map of the sky
The Elementary block:
a Galaxy
From COBE to WMAP to Planck Surveyor
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Cosmology today … and tomorrow
SNLS, ESSENCE, SNIFS, CSP, …
Weak Lensing,
CFHTLS,
DUNE
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Is particle physics useful outside the lab?
YES!
• Tune Kamae: Turning the Cosmos into a Particle Physics Lab
OR/AND:
using particle physics to understand the X-Cosmos
Charling Tao, Sulak Festschrift, Oct 21-22,2005
The Golden age of « astro particles »
experiments
c
n, g, p, e+
Shore station
Light Sources
K40
Bioluminescence
Optical M odules
m track
hydrophone
Cerenkov Light
~60m
float
Compass,
tilt meter
2500m
Electro-optical
underwater cable
~40km
300m
Electronics Containers
Readout Cables
50m
anchor
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Junction box
acoustic detector
Neutrino mass from Cosmology?
Data
Authors
Mn =  mi
2dFGRS
Elgaroy et al. 02
< 1.8 eV
WMAP+2dF+…
Spergel et al. 03
< 0.7 eV
WMAP+2dF
Hannestad 03
< 1.0 eV
SDSS+WMAP
Tegmark et al. 04
< 1.7 eV
WMAP+2dF+
SDSS
Crotty et al. 04
< 1.0 eV
Clusters +WMAP
Allen et al. 04
0.56+0.30-0.26 eV
All upper
limits
95%Oct
CL,
but different
Charling
Tao, Sulak
Festschrift,
21-22,2005
assumed priors !
Slide from Ofer Lahav
Neutrinos and DE
Atmospheric neutrinos 
neutrinos oscillate and have mass
1998
Cosmology measurements
Dark energy, r ~ (10-2.5eV)4
Could neutrino energy density scale like dark energy?
Requires neutrino ‘mass’ to increase with scale factor
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Connexions Neutrino mass /DE
Rob Fardon, A.E.Nelson., Neal Weiner; astro-ph/0309800
David B. Kaplan, A.E.Nelson., Neal Weiner; hep-ph/0401099
Kathryn Zurek, hep-ph/0405141
• Direct couplings
Q ll 
L M
c
R
QN N R
mn
Xinmin Zhang etal. PRD68, 087301 (2003)
• Derivative couplings:
CPT violation
-M. Li, X. Wang, B. Feng, X. Zhang, Phys.Rev. D65 (2002) 103511
Quintessential Leptogenesis
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Speculations or reality?
Future experiments to show
Experimental To Do list (A. Nelson)
 Document and consider environment of neutrino path in neutrino
oscillation experiments
 Consider 13 measurements in reactor experiments with pathlength in
air and in rock
 Consider environment of neutrinos in direct mass search and 0nbb
measurements
 Short baseline experiments to search for heavier sterile neutrinos
with small mixing angles; consider varying density of material in
neutrino path
Charling Tao, Sulak Festschrift, Oct 21-22,2005
The Golden age of Neutrino Physics!
CP Violation in the lepton Sector
Dark Energy
Charling Tao, Sulak Festschrift, Oct 21-22,2005
The life of a graduate student in the 70’s?
• Harvard sigma 7 computer
– 1966: Scientific Data Systems (SDS)
– Computing with cards
– One night for a 800 bpi tape and risk of crash VERY high!
–  More thinking before using computers
Beginning of internet : arpanet use limited
Talks: No Powerpoint
•
•
• Papers : no archiv, Phys. Rev.
•
•
Not flooded with papers
sending reprints to requests and libraries
Largest experiment : CHIO DIS muon ~35 physicists
You could understand and control all aspects of experiments
More scientists and less full time managers
No FPGA (screwdriver and soldering iron electronics)
• Very few women in graduate school: still very few women
Charling Tao, Sulak Festschrift, Oct 21-22,2005
How is the life of an experimental
particle graduate student in 2005?
• Difficulty in carrying « independent » research in
large experimental particle physics groups
– Graduate school in particle physics teaches how to be a
good team player
• Long delays between experimental designs and
results
• Strong specialization in big teams and pixellisation
of responsibility
 threat of extinction
Charling Tao, Sulak Festschrift, Oct 21-22,2005
BUT most graduate students are happy!
And
… Physics is exciting!
So what do we worry about?
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Evolving Universe
Evolving Physics
Evolving People
How to Anticipate Next Golden age ?
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Hypothesis: Frontiers of physics evolves
How can that be tested?
Look at people evolution?
Look at PhD.Thesis topics?
Data Not conclusive !
• Low statistics
• Large bias!
Charling Tao, Sulak Festschrift, Oct 21-22,2005
• Hidden variables???
Source:
Harvard U.
http://www.physics.harvard.edu/academics/phds.html
Sorry for the bias!
Did not find online WEB data from BU
or any other University
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Harvard PhD 1979, 10/20 in particle physics
•AFFLECK, IAN KEITH,. Some Results on Vacuum Decay. (Coleman)
•ALVAREZ, ORLANDO, Conformal Invariance in Quantum Field Theory.
(Weinberg)
•DAVIS, SAMUEL, Predictions and Limitations of Perturbative QCD.
(Georgi)
•DE LUCCIA, FRANK JOSEPH, The Fate of the False Vacuum: Induced
Decay and Gravitational Effects on Spontaneous Decay. (Coleman)
•RICH, JAMES ARNOLD, Trimuon Production by High Energy Neutrinos.
(Rubbia)
•ROCEK, MARTIN,. Aspects of Spontaneous Symmetry Breakdown of
Supersymmetry. (Wu)
•SHEIMAN, JOHATHAN LEWIS, Topics in the Theory of
Leptoproduction. (Georgi)
•SMOLIN, LEE, Studies in Quantum Gravity. (Coleman)
•SOBELMAN, GERALD EDWARD, Asymptotic Estimates and Borel
Resummation for a Doubly Anharmonic Oscillator. (Coleman)
•TAO, CHARLING SUN, The Structure and Formation of Hadrons: An
Experiment with a Muon Beam of 219 GeV on a Hydrogen Target. (Wilson)
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Harvard PhD 2004 7/21 related
particle physics and cosmology
• ABRAHAM, MATHEW CHEERAN, Hot Electron Transpoort
and Current Sensing. (Westervelt)
• BOWDEN, NATHANIEL SEAN, Production of Cold
Antihydrogen During the Positron Cooling of Antiprotons.
(Gabrielse)
• CHANG, SPENCER, Topics in Little Higgs Physics (Georgi)
• MOODY, AREEZ MINOO, Thermodynamics of ultracold
singly charged particles. (Heller)
• ODOM, BRIAN CARL, Measurement of the Electron g-Factor
in a Sub-Kelvin Cylindrical Cavity. (Gabrielse)
• OXLEY, PAUL KEVIN, Production of Slow Antihydrogen from
Cold Antimatter Plasmas. (Gabrielse)
• SON, JOHN SANG WON,. Superstring Theory in AdS_3 and
Plane Waves (Minwalla)
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Agreement with A. Rosowsky’s proposal!
For graduate students:
better small experiments – atomic physics?
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Conclusions
• It was great to be a graduate student in the ’70s
– Hope it is still true for today’s students
– Certainly is different
• Small experiments are better training grounds to learn
independence and experience a full experimental cycle
Is there a future for particle physics?
Pioneering frontiers physics exist and is part of the future
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Thank you !
Charling Tao, Sulak Festschrift, Oct 21-22,2005
Harvard University PhD 2005 3/11
related to particle physics and cosmology
NEITZKE, ANDREW M., Toward a Nonperturbative Topological String.
(Vafa)
SPECK, ANDREW J., Two Techniques Produce Slow Antihydrogen
(Gabrielse)
THOMPSON, DAVID MATTOON, Holography and Related Topics in String
Theory (Strominger)
Charling Tao, Sulak Festschrift, Oct 21-22,2005