Download Heuer.Coll - Farewell Colloquium for Rolf-Dieter Heuer

Why Spend Time Annihilating Matter with Anti-matter?
Rolf-Dieter Heuer leaves
DESY (again) to go to
CERN (again)
matter
anti-m
Hamburg
5 December 2007
Albrecht Wagner, Hamburg
RDH
1
A leptonic love affair - e+e- colliders
• Born
1948
• The very early history (DESY-Heidelberg) 1974-1977 PhD HD
• The early history (Jade)
1977-1983 Postdoc HD
• The not so recent past (OPAL)
1984-1999 Staff CERN
• Preparing the possible future (ILC)
1998-2008 Prof HH
• Since Dec 2004 Director of Research for Particle and Astroparticle
Physics
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The Early Days of
e+e- Physics
Everything started with a discrepancy:
1973
Is this excess
real, what is it?
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The Past and Future Role of e+e- Colliders
Rolf starts his thesis
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The Power of e+ e- Colliders
•
well defined production process, simple kinematics
e+
e-
•
precise knowledge of quantum numbers in initial state
•
energy and momentum of all partons known
•
energy of system can be varied
•
precise (<%) knowledge of the cross sections
•
low background
•
polarisation of e- and e+ beams possible
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DESY/HD and Jade at DORIS/PETRA
DORIS
1974
first events
3 < E < 10 GeV
DESY-HD
PETRA
1974
proposal
1978 first events
13 < E < 47 GeV
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A Precise Measurement of the t-Mass
W. Bartel, P. Dittmann, P. Duinker, J. Olsson, L. O'Neill, D. Pandoulas,
P. Steffen, U. Fritscher, J. Heintze, G. Heinzelmann, R.D. Heuer, H.
Rieseberg and A. Wagner
DESY, Physikalisches Institut der Uni Heidelberg,
mt = 1.787 + 0.010 – 0.018 GeV
From a fit to the energy dependence of the
cross section
Today: mt = 1776.69 +- 0.18 +– 0.15 MeV
Thesis of Rolf: (1977)
Neutral decays of the Y’ (3.7) Resonance
BR (Y’ -> neutral (not J/Y)) = (2.0 +- 0.8)10-3
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Detector and Measurement
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PETRA Construction
Construction started in 1976
thanks to H. Schopper and
G.A. Voss
The project advanced very
fast
Construction completed in
1978, 6 months ahead of
schedule
First stored beam in July
1978
Competition with SLAC (PEP)
Five experiments approved CELLO, JADE, Mark J,
PLUTO, TASSO
With PETRA DESY became
international
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The Detector Layout
Essential features:
- Large solid angle
- Excellent tracking
- Good energy measurement
- Muon detection
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The Proposed Physics Programme
LoI for JADE:
• Measurement of magnitude and energy dependence of hadronic
cross section
• Search for new quarks and leptons (mainly top)
• Measurement of magnitude of electroweak interference
• Study of hadronic final states, prove existence or nonexistence of jets
• Is QED correct at high energies?
• Study decays of heavy quarks
• Study photon-photon interactions
…but nothing about gluons
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Discovery of Gluon
Field theory predicted that the
outgoing quarks radiate field
quanta (gluons)
The probability for radiation is
~ as(q2)/p, which at PETRA
energy is ~ 10%.
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Discovery of the Gluon
PETRA as test bed of
QCD:
quarks radiate gluons
-> 3 jet events
planar events with 3-jet
structure
one sided jet broadening
The quantum of the
strong force was
discovered and studied at
a lepton collider
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Lepton Photon Symposium 1979
Lepton-Photon Symposium, Fermilab
23– 29 August 1979
All 4 PETRA experiments presented their data.
The conclusion of all four experiments (JADE, Mark J, PLUTO
and TASSO) was very similar:
To cite S. Orito (JADE, Tokyo):
“Quantitative as well as qualitative properties of the planar 3jet events agree in detail with the predictions based on the
gluon bremsstrahlung process and the suggested
fragmentations. This strongly suggests hard gluon
bremsstrahlung as origin of the planar 3-jet events.”
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Most cited PETRA papers
1)
W. Bartel et al., R.D. Heuer, EXPERIMENTAL STUDIES ON MULTI – JET
PRODUCTION IN E+ E- ANNIHILATION AT PETRA ENERGIES.
Z.Phys.C33:23,1986. (cit. 660 times in HEP (SPIRES-SLAC))
2)
R. Brandelik et al., EVIDENCE FOR PLANAR EVENTS IN E+E- ANNIHILATION
AT HIGH-ENERGIES.
Phys.Lett.B86:243,1979. (412)
3)
S. Bethke et al., R.D. Heuer, EXPERIMENTAL INVESTIGATION OF THE ENERGY
DEPENDENCE OF THE STRONG COUPLING STRENGTH.
Phys.Lett.B213:235,1988. (411)
Discovery of the Gluon, the particle mediating the strong force
1995: EPS HEP Prizes for Gluon discovery
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Muon Asymmetry
Interference of electromagnetic and weak interaction leads
to a forward-backward asymmetry
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M 2 ( Z )  71  10
( 570
) GeV
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Search for the Top Quark
Many theoretical
predictions
expected the topquark to lie ‚just
around the corner‘
scan for narrow
resonance
R  3.88  0.22
as expected for
udscb + QCD corr.
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JADE
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JADE
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JADE
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Then Rolf went to CERN …
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… to join OPAL at LEP
• Detector pictures
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OPAL – Main Physics Aims (from LoI 1982)
• Observation of Z0 (mass, BR, width …)
• Measure number of generations
• Test of SM
– Precise study of electroweak interference
– Weak decays of heavy quarks
– Search for the Higgs
• Search for new physics
– New flavours
– New heavy leptons
– Supersymmetry
– Technicolour
• Study of QCD
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The Team
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Building the Jet-Chamber
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LEP Events
qqmm
qqqq
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Cross sections
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Three Generations
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Electroweak Precision Tests
The SM is tested to
unprecedented accuracy
No deviations observed
precision data tell us
something about mass
range not accessible
today
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Search for the Top Quark
Indirect determination of
the top mass
possible due to
• precision measurements
• known higher order
electroweak corrections
Mt 2
Mh
(
) , ln(
)
MW
MW
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Rolf’s Roles in OPAL
• Building the Jet Chamber
with the German
universities (coordinator)
• Run coordinator
• Spokes Person
• Motivating people …
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The possible future
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A memorable event
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The TESLA Project
Superconducting
electron-positron
linear collider
with
integrated X-ray laser
http://tesla.desy.de
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The Road Map of Particle Physics
The Key Questions of Particle Physics
•
•
•
•
What is matter ?
What are the forces ?
Can quantum physics and general relativity be united?
What happened in the very early universe ?
Where do the experimental answers lie?
• At highest energies
Large Hadron Collider
construction finished at CERN
• In precision measurements
Electron-Positron Collider
TESLA project -> ILC
Physics and experience teach us that we need these different tools to
answer these questions and that they complement each other
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Extra Spatial Dimensions
cross section for anomalous single
photon production
d = # of extra dimensions
e+e- -> gG
Energy
•In how many dimensions
do we live?
Emission of gravitons into
extra dimensions
+ emission of g
(or one jet)
measurement of cross
sections at different
energies allows to
determine number and scale
of extra dimensions
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The Site Preparation
Two independent
radiological evaluations
Preparation of
environmental impact
study
Research Campus Ellerhoop
Agreement between the
states SchleswigHolstein and HH for
joint legal procedure
Regular information of
all persons living along
TESLA
Preparation of
“Planfeststellung”
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TESLA … followed by the ILC
• After the decision of the German Government to build the
XFEL and PETRA and to support DESY in the further
preparation of the ILC, Rolf was active in many ways in
promoting the ILC:
– Leading the parameter group of the ILCSC
– Leading a very thriving group at the University of HH and
DESY
– Organising LCWS 2007
– Giving many talks
– Helping build the bridge to CLIC
– Etc., etc.
– Driving a car with the number plate HH-LC …..
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Good by and good Luck – the end of a love affair?
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Many Thanks, Rolf
For your strong support of particle physics
• In the world
• In Europe
• In Germany (Helmholtz-Allianz)
• At DESY
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