J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 EXOTIC ATOM RESEARCH AT DAΦNE J. Marton Institute for Medium Energy Physics Austrian Academy of Sciences DAFNE EXOTIC ATOM RESEARCH

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 Exotic Atom Research by IMEP Main field: Hadron physics – hadronic atoms Kaonic atoms K - p, K - LNF / INFN Contributions of IMEP to other topics in exotic atom research  Search for nuclear clusters bound by K - (GSI, J-PARC)  Antiprotonic atoms (CERN, FLAIR/GSI-future)  Pionic atoms πH (PSI)  Theoretical studies (collaboration with TU Vienna)

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 IMEP: Member of DEAR / SIDDHARTA G. Beer 1, A.M. Bragadireanu 2, M. Cargnelli 3, C. Curceanu(Petrascu) 4,2, J.P. Egger 5, H. Fuhrmann 3, C. Guaraldo 4 (spokesperson), M. Iliescu 4,2, T. Ishiwatari 3, K. Itahashi 6, M. Iwasaki 6, P. Kienle 3, B. Lauss 7, V. Lucherini 4, L. Ludhova 8, J. Marton 3, F. Mulhauser 8, T. Ponta 2,4, L.A. Schaller 8, R. Seki 9,10, D. Sirghi 4, F. Sirghi 4, P. Strasser 6 and J. Zmeskal 3 1 Univ. of Victoria; 2 Inst. of Physics and Nuclear Engineering “Horia Hulubei”; 3 Institute for Medium Energy Physics; 4 INFN Laboratori Nazionali di Frascati; 5 Université de Neuchâtel; 6 RIKEN; 7 University of California; 8 Université de Fribourg; 9 California Institute of Technology; 10 California State University I3 Hadron Physics in FP6/EC – Joint Research Activity SIDDHARTA in cooperation with LNF, MPG, PNSensor, Politecnico Milan, IFIN-HH. SIDDHARTA Silicon Drift Detectors for Hadronic Atom Research by Timing Applications SIDDHARTA Silicon Drift Detectors for Hadronic Atom Research by Timing Applications

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 Motivation X-ray transitions in kaonic atoms – precision spectroscopy Kaonic hydrogen isotopes: low energy QCD studies Simplest exotic atoms with strangeness  Information on  (1405) sub-threshold resonance important for research on deeply bound kaonic states  Determination of the isospin dependent KN scattering lengths  Testing chiral symmetry breaking in systems with strangeness hadronic shift ε 1s and width Γ 1s directly observable by X-ray spectroscopy kaonic hydrogen „puzzle“ solved – but: precision data missing kaonic deuterium never measured before

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 Our goals Measurement of the hadronic shift and width of hydrogen at the percent level First measurement of kaonic deuterium Extraction of the isospin-dependent scattering lengths with kaonic hydrogen and kaonic deuterium data SIDDHARTA Silicon Drift Detectors for Hadronic Atom Research by Timing Applications SIDDHARTA Silicon Drift Detectors for Hadronic Atom Research by Timing Applications

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 LNF Electron – Positron collider with collision energy tuned to the Φ meson resonance at 1.02 GeV c.m. Monoenergetic kaons from Φ meson decay Φ  K + K - (branching ~ 50%) Ideal kaon trigger Pion background very small Kaon production ~ 3×10 6 K - per day  Ideal facility for exotic (kaonic) atom research DEAR

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 DEAR Experimental Set-up X-ray spectroscopy by CCD array (16 CCD-55)

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 DAPHNE / LNF

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 Results on Kaonic Nitrogen Thesis T. Ishiwatari (IMEP), to be published in Phys. Lett. B  3 X-ray transitions first measured  Extraction of the transition yields  Impact on cascade calculations  Kaonic nitrogen nearly fully stripped of electrons: high precision measurement of the charged kaon mass

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 Results on Kaonic Hydrogen 2 independent data analyses by LNF and IMEP  consistent results repulsive shift verified smaller shift, width smaller error bars K , K  disentangled Analysis by M. Cargnelli (IMEP) Combined result for hadronic shift and width (preliminary) Shift:  1s = ± 46 eV Width:  1s = 249 ± 132 eV

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 DEAR Results (preliminary) width  1s  [eV] KpX shift  1s [eV] Davies et al, 1979 Izycki et al, 1980 Bird et al, 1983 repulsive attractive KpX (KEK) M. Iwasaki et al, 1997  = ± 63 ± 11 eV  = 407 ± 208 ± 100 eV New theoretical studies: Ivanov et al / 2004 Meißner, Raha, Rusetsky 2004 DEAR prelim.

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 New X-ray detectors providing –timing capability  background suppression by using the kaon-X ray time correlation –excellent energy resolution –high efficiency, large solid angle –dedicated compact geometry Best choice: SDD (silicon drift detectors)  R&D within SIDDHARTA Next Steps SIDDHARTA Silicon Drift Detectors for Hadronic Atom Research by Timing Applications SIDDHARTA Silicon Drift Detectors for Hadronic Atom Research by Timing Applications In the next stage of the experiment we expect a substantial improvement in signal-to-noise ratio by more than 2 orders of magnitude

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 Next Steps cont‘d New design for target-detector system with high efficiency Example: Toroidal Setup with SDDs (work in progress) Large area SDDs (1cm 2 each, total area ~ 200 cm 2 ) e+e+ e-e- Cryogenic gas target volume SDDs Structure material carefully selected - Vienna)

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 Summary DEAR one of the first experiments at DAPHNE First production of exotic atoms at DAFNE Measurements on kaonic nitrogen and finally kaonic hydrogen Preliminary results on hadronic shift and width in kaonic hydrogen: repulsive hadronic shift in K - p verified. smaller values and better precision for shift and width. K β, K γ resolved for the first time. Potential of the method using SDDs demonstrated by test measurements  future high precision measurements on kaonic atoms are feasible SIDDHARTA Silicon Drift Detectors for Hadronic Atom Research by Timing Applications SIDDHARTA Silicon Drift Detectors for Hadronic Atom Research by Timing Applications

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 Outlook SDDs with trigger capability (SIDDHARTA project) New target-detector set-up in progress Next experiments planned Precison measurement of kaonic hydrogen. Measurement of kaonic deuterium (first ever) Long range perspectives: kaonic helium Precision measurement of kaon mass

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 Post Scriptum "The most important experiment to be carried out in low energy K-meson physics today is the definitive determination of the energy level shifts in K - p and K - d atoms, because of their direct connection with the physics of the KN interaction and their complete independence of all other kind of measurements which bear on this interaction“ R.H. Dalitz

J. Marton / IMEPRECFA Meeting, Innsbruck, March 26, 2004 The End