RECFA September Kenneth Österberg, University of Helsinki Experimental e + e - physics – LEP&LC DELPHI Major finnish LEP contribution analysis contribution OPAL L3 ALEPH Kenneth Österberg, lecturer at High Energy Physics Division, Department of Physical Sciences & project leader at Helsinki Institute of Physics, University of Helsinki

RECFA September Kenneth Österberg, University of Helsinki Barrel Hadron Calorimeter Forward Hadron Calorimeter Vertex Detector Finnish DELPHI contributions (1983-) & Physics analysis

RECFA September Kenneth Österberg, University of Helsinki

RECFA September Kenneth Österberg, University of Helsinki

RECFA September Kenneth Österberg, University of Helsinki DELPHI Vertex Detector ( ) 1990: Two layers of single-sided sensors 1990: Two layers of single-sided sensors Mechanical support structure and readout Mechanical support structure and readout 1991: A third single-sided layer added (& beam pipe radius reduced) 1991: A third single-sided layer added (& beam pipe radius reduced) Finnish VTT sensors used, mechanical support structure & mounting Finnish VTT sensors used, mechanical support structure & mounting 1994: Two layers exchanged to double-sided double-metal sensors 1994: Two layers exchanged to double-sided double-metal sensors Double-sided double-metal sensor development, mounting & cooling Double-sided double-metal sensor development, mounting & cooling Design & feasibility studies; development of the reconstruction software Design & feasibility studies; development of the reconstruction software Jig setup for outer layer module assembly in the Helsinki detector lab

RECFA September Kenneth Österberg, University of Helsinki Three extended double-sided layers & forward pixels+ministrips crowns Three extended double-sided layers & forward pixels+ministrips crowns Outer layer module assembly in Helsinki and mounting at CERN Outer layer module assembly in Helsinki and mounting at CERN Software development work & coordination Software development work & coordination Running responsibility & full project coordination Running responsibility & full project coordination DELPHI Silicon Tracker ( )

RECFA September Kenneth Österberg, University of Helsinki Physics analysis LEP1 Searches: New particles in events with  ’s (L3), lepton flavour violation, heavy ’s, squarks and charged Higgses. Searches: New particles in events with  ’s (L3), lepton flavour violation, heavy ’s, squarks and charged Higgses. B- and  -physics: b  ul decays, exclusive charmless B meson decays, inclusive charmless and double-charm b decays, moments of the lepton spectrum in semileptonic b decays, charged K’s in  decays, B 0 s and  b mass and search for b  s  and b  s decays. B- and  -physics: b  ul decays, exclusive charmless B meson decays, inclusive charmless and double-charm b decays, moments of the lepton spectrum in semileptonic b decays, charged K’s in  decays, B 0 s and  b mass and search for b  s  and b  s decays. Final state interactions: colour portraits in bbg events, dead cone effect in heavy flavour decays, interference of neutral kaons and production of quarkonia in hadronic Z 0 decays. Final state interactions: colour portraits in bbg events, dead cone effect in heavy flavour decays, interference of neutral kaons and production of quarkonia in hadronic Z 0 decays. signal of b  ul transitions  the LEP combined result gives ~15 % precision on |V ub |. DELPHI

RECFA September Kenneth Österberg, University of Helsinki Physics analysis LEP2 Searches: Charged and neutral Higgses. Searches: Charged and neutral Higgses. QCD: Colour coherence phenomena (colour portraits & interconnection effects). QCD: Colour coherence phenomena (colour portraits & interconnection effects). Electroweak: Hadronic cross section (L3). Electroweak: Hadronic cross section (L3). DELPHI preliminary Limit assuming no H   W  * A decay BR(H +  ) M H (GeV/c 2 ) Final DELPHI result on the search for the charged Higgs that is just to be published !! (finnish analysis of the fully hadronic decay channel)

RECFA September Kenneth Österberg, University of Helsinki Current activities Measurement of statistical moments of the leptonic energy spectrum in semileptonic B decays at LEP By measuring statistical moments of leptonic & hadronic B decay spectra, one can constrain the parameters of the model describing B hadrons  reduce the theoretical uncertainty related to the extraction of |V cb | from experimental data. DELPHI preliminary for more details see M. Battaglia et al. (with L. Salmi), hep-ph/ (GeV 2 /c 4 )   m b (GeV/c 2 )

RECFA September Kenneth Österberg, University of Helsinki Some unofficial statistics Theses Theses (including both analysis and detector related): 12 PhD’s (+ 2 more to be finalized by summer 2004) 12 PhD’s (+ 2 more to be finalized by summer 2004) ~ 25 MSc and Lic. Phil. ~ 25 MSc and Lic. Phil. Publications Publications: ~ 300 DELPHI physics papers in refereed journals with  10  finnish authors (L3: ~ 150 papers and  2  authors) ~ 300 DELPHI physics papers in refereed journals with  10  finnish authors (L3: ~ 150 papers and  2  authors) ~ 25 of those with Finn(s) as main/one of the main contributors ~ 25 of those with Finn(s) as main/one of the main contributors ~ 35 papers in refereed journals on detectors or experimental methods by finnish authors ~ 35 papers in refereed journals on detectors or experimental methods by finnish authors  50 internal notes by finnish authors  50 internal notes by finnish authors Disclaimer: numbers should be taken as approximative, not as absolute & factual numbers !!

RECFA September Kenneth Österberg, University of Helsinki Linear collider (LC) Extending knowledge & experience to a future LC Assume Higgs is found at LHC  studies at LC important to characterize the Higgs field Measurement precision of Higgs Br’s, width & potential + charged Higgs mass reconstruction Conceptual design of a Vertex Tracker Done within the framework of the 2 nd ECFA/DESY study on physics & detectors for a e+e- LC  contributions to TESLA TDR Latest addition:  and A FB in top pair production at a few TeV LC that is very sensitive to tan 

RECFA September Kenneth Österberg, University of Helsinki Conclusions & reflections 1 st finnish involvement in a large scale HEP experiment that included all aspects (design & feasibility work, hardware, software & analysis) !! 1 st finnish involvement in a large scale HEP experiment that included all aspects (design & feasibility work, hardware, software & analysis) !! Finnish LEP/DELPHI effort was successful... however activity is winding down (to be completed by the end of 2004). Finnish LEP/DELPHI effort was successful... however activity is winding down (to be completed by the end of 2004). Knowledge and experience have been acquired and already have been applied to feasibility studies for future LC  establish a small scale project focused on finnish detector R&D and finnish physics feasibility studies for future LC !! Knowledge and experience have been acquired and already have been applied to feasibility studies for future LC  establish a small scale project focused on finnish detector R&D and finnish physics feasibility studies for future LC !! Students need more supervision (modern HEP experiments are complex)  increase number of supervisors (establish a few new finnish post-doc type positions in experimental HEP that should be both attractive & longer term) !! Students need more supervision (modern HEP experiments are complex)  increase number of supervisors (establish a few new finnish post-doc type positions in experimental HEP that should be both attractive & longer term) !!