EXOTIC ATOM RESEARCH AT DANE J Marton Institute

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

Exotic Atom Research by IMEP Main field: Hadron physics – hadronic atoms Kaonic atoms K-p, K-d @ LNF / INFN Contributions of IMEP to other topics in exotic atom research ØSearch for nuclear clusters bound by K- (GSI, J-PARC) ØAntiprotonic atoms (CERN, FLAIR/GSI-future) ØPionic atoms πH (PSI) ØTheoretical studies (collaboration with TU Vienna) J. Marton / IMEP RECFA 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 SIDDHARTA Silicon Drift Detectors for Hadronic Atom Research by Timing Applications J. Marton / IMEP I 3 Hadron Physics in FP 6/EC – Joint Research Activity SIDDHARTA in cooperation with LNF, MPG, PNSensor, Politecnico Milan, IFIN-HH. RECFA 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 hadronic shift ε 1 s and width Γ 1 s directly observable by X-ray spectroscopy kaonic hydrogen „puzzle“ solved – but: precision data missing kaonic deuterium never measured before 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 J. Marton / IMEP RECFA 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 J. Marton / IMEP RECFA Meeting, Innsbruck, March 26, 2004

DAΦNE @ LNF Electron – Positron collider with collision energy tuned to the Φ meson resonance at 1. 02 Ge. V c. m. üMonoenergetic kaons from Φ meson decay Φ K+ K- (branching ~ 50%) üIdeal kaon trigger üPion background very small üKaon production ~ 3× 106 K- per day DEAR Ideal facility for exotic (kaonic) atom research J. Marton / IMEP RECFA Meeting, Innsbruck, March 26, 2004

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

Experiment @ DAPHNE / LNF J. Marton / IMEP RECFA Meeting, Innsbruck, March 26, 2004

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

Results on Kaonic Hydrogen 2 independent data analyses by LNF and IMEP consistent results Analysis by M. Cargnelli (IMEP) ürepulsive shift verified üsmaller shift, width üsmaller error bars üKb, Kg disentangled Combined result for hadronic shift and width (preliminary) Shift: 1 s = - 194 ± 46 e. V Width: 1 s = 249 ± 132 e. V J. Marton / IMEP RECFA Meeting, Innsbruck, March 26, 2004

DEAR Results (preliminary) 1000 attractive repulsive Kp. X (KEK) 200 0 -500 J. Marton / IMEP Izycki et al, 1980 DEAR prelim. 0 shift 1 s [e. V] RECFA Meeting, Innsbruck, March 26, 2004 Bird et al, 1983 400 Kp. X Davies et al, 1979 600 M. Iwasaki et al, 1997 = - 323 ± 63 ± 11 e. V = 407 ± 208 ± 100 e. V width 1 s [e. V] 800 500 New theoretical studies: Ivanov et al. 2003 / 2004 Meißner, Raha, Rusetsky 2004

Next Steps • 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 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 / IMEP RECFA 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 (1 cm 2 each, total area ~ 200 cm 2) SDDs e+ e. Cryogenic gas target volume Structure material carefully selected (PIXE@VERA - Vienna) J. Marton / IMEP RECFA Meeting, Innsbruck, March 26, 2004

Summary üDEAR one of the first experiments at DAPHNE üFirst production of exotic atoms at DAFNE üMeasurements on kaonic nitrogen and finally kaonic hydrogen Preliminary results on hadronic shift and width in kaonic hydrogen: ü repulsive hadronic shift in K-p verified. ü smaller values and better precision for shift and width. ü Kβ, Kγ resolved for the first time. üPotential 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 J. Marton / IMEP RECFA 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 / IMEP RECFA 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 / IMEP RECFA Meeting, Innsbruck, March 26, 2004

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