1 Why Spend Time Annihilating Matter with Anti-matter? Rolf-Dieter Heuer leaves DESY (again) to go to CERN (again) Hamburg 5 December 2007 Albrecht Wagner, Hamburg RDH matter anti-m

2 A leptonic love affair - e+e- colliders Born1948 The very early history (DESY-Heidelberg) PhD HD The early history (Jade) Postdoc HD The not so recent past (OPAL) Staff CERN Preparing the possible future (ILC) Prof HH Since Dec 2004 Director of Research for Particle and Astroparticle Physics

3 The Early Days of e + e - Physics Is this excess real, what is it? Everything started with a discrepancy: 1973

4 The Past and Future Role of e + e - Colliders Rolf starts his thesis

5 The Power of e + e - Colliders well defined production process, simple kinematics 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 e+e+ e-e-

6 DESY/HD and Jade at DORIS/PETRA PETRA 1974 proposal 1978 first events 13 < E < 47 GeV DORIS 1974 first events 3 < E < 10 GeV DESY-HD

7 A Precise Measurement of the  -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, Thesis of Rolf: (1977) Neutral decays of the  ’ (3.7) Resonance BR (  ’ -> neutral (not J/  )) = ( )10 -3 m  = – GeV From a fit to the energy dependence of the cross section Today: m  = – 0.15 MeV

8 Detector and Measurement

9 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 Five experiments approved - CELLO, JADE, Mark J, PLUTO, TASSO With PETRA DESY became international PETRA Construction Competition with SLAC (PEP)

10 The Detector Layout Essential features: - Large solid angle - Excellent tracking - Good energy measurement - Muon detection

11 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 non- existence of jets Is QED correct at high energies? Study decays of heavy quarks Study photon-photon interactions …but nothing about gluons

12 Discovery of Gluon Field theory predicted that the outgoing quarks radiate field quanta (gluons) The probability for radiation is ~  s (q 2 )/  which at PETRA energy is ~ 10%.

13 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

14 Lepton Photon Symposium 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 3- jet 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.” Lepton-Photon Symposium, Fermilab 23– 29 August 1979

15 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

16 Muon Asymmetry Interference of electromagnetic and weak interaction leads to a forward-backward asymmetry

17 Search for the Top Quark Many theoretical predictions expected the top- quark to lie ‚just around the corner‘ scan for narrow resonance as expected for udscb + QCD corr.

18 JADE

19 JADE

20 JADE

21 Then Rolf went to CERN …

22 … to join OPAL at LEP Detector pictures

23 OPAL – Main Physics Aims (from LoI 1982) Observation of Z 0 (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

24 The Team

25 Building the Jet-Chamber

26 LEP Events q q  q q

27 Cross sections

28 Three Generations

29 Electroweak Precision Tests The SM is tested to unprecedented accuracy No deviations observed precision data tell us something about mass range not accessible today

30 Search for the Top Quark Indirect determination of the top mass possible due to precision measurements known higher order electroweak corrections

31 Rolf’s Roles in OPAL Building the Jet Chamber with the German universities (coordinator) Run coordinator Spokes Person Motivating people …

32 The possible future

33 A memorable event

34 The TESLA Project Superconducting electron-positron linear collider with integrated X-ray laser

35 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 Colliderconstruction finished at CERN In precision measurements Electron-Positron ColliderTESLA project -> ILC Physics and experience teach us that we need these different tools to answer these questions and that they complement each other The Road Map of Particle Physics

36 Extra Spatial Dimensions Emission of gravitons into extra dimensions + emission of  (or one jet) measurement of cross sections at different energies allows to determine number and scale of extra dimensions cross section for anomalous single photon production Energy  = # of extra dimensions e+e- ->  G In how many dimensions do we live?

37 The Site Preparation Two independent radiological evaluations Preparation of environmental impact study Agreement between the states Schleswig- Holstein and HH for joint legal procedure Regular information of all persons living along TESLA Preparation of “Planfeststellung” Research Campus Ellerhoop

38 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 …..

39 Good by and good Luck – the end of a love affair?

40 Many Thanks, Rolf For your strong support of particle physics In the world In Europe In Germany (Helmholtz-Allianz) At DESY