The AMADEUS project – precision studies of the low-energy antikaon nucleon interaction Johann Zmeskal, SMI – Vienna, Austria for the AMADEUS collaboration International Workshop on Hadronic Atoms and Kaonic Nuclei ECT*, Trento 12 – 16 October 2009

AMADEUS at DA  NE A ntikaon M atter A t D A  NE: E xperiments with U nraveling S pectroscopy International Workshop on Hadronic Atoms and Kaonic Nuclei

AMADEUS collaboration International Workshop on Hadronic Atoms and Kaonic Nuclei 110 scientists from 34 Institutes of 14 Countries Letter of Indent Study of deeply bound kaonic nuclear states at DA  NE2 March 2006

Introduction  Investigations of antikaon-mediated bound nuclear systems were done, are ongoing or planned at several facilities - KEK, LNF, GSI, J-PARC, CERN-AD  Next-generation experiments should be exclusive, i.e. require the measurement of formation and decay  DAΦNE2 aims to do that with - stopped K − in low-density gas targets - unique features available at DAΦNE2 - measurement of all decay particles, charged and neutral, using the KLOE detector International Workshop on Hadronic Atoms and Kaonic Nuclei

DA  FN at LNF International Workshop on Hadronic Atoms and Kaonic Nuclei

AMADEUS’s main aim is to perform a full acceptance, high precision measurement of antikaon- mediated bound nuclear systems – studying the formation as well as the decay process, by implementing the KLOE detector with an inner AMADEUS dedicated setup, containing a cryogenic target and a trigger system (and an inner tracker in a second phase). First actions: Results of the KLOE data analysis were presented by  O. Vazquez Test measurements of the AMADEUS trigger system were presented by  A. Scordo The goal of AMADEUS International Workshop on Hadronic Atoms and Kaonic Nuclei

The experimental program - 1 study of the (most) fundamental antikaon-mediated bound nuclear systems, the kaonic dibaryon states: ppK- and (pnK-) produced in a 3 He gas target, by their formation and decay processes and as next step, the kaonic tri-baryon states: ppnK- and (pnnK-) produced in a 4 He gas target, by their formation and decay processes International Workshop on Hadronic Atoms and Kaonic Nuclei

The experimental program - 2  Low-energy charged kaon cross section on p, d, He-3 and He-4, for K - momentum lower than 100 MeV/c  The K - nuclear interactions in Helium (poorly known – based on one paper from 1970 …)  Properties of  and charged  ´s  Resonance states as  (1405) or the  (1385) in addition their behaviour in a nuclear medium can be studied International Workshop on Hadronic Atoms and Kaonic Nuclei

Production methods of antikaon-mediated bound nuclear cluster  stopped K - reactions on light nuclei  in-flight K - reactions  protons on proton (or light nuclei)  heavy ion collisions  strangeness production in antiproton annihilation International Workshop on Hadronic Atoms and Kaonic Nuclei

tri-baryon systems with S = -1 tri-baryon systems with S = -1  formation process: K He  ppnK - + n  possible decay channels: ppnK -   + d   + p + n   - + p + p   0 + d   0 + p + n   p +  - n +  0  -  n +  -  0   +  International Workshop on Hadronic Atoms and Kaonic Nuclei

Hyperon production K - N  Y  International Workshop on Hadronic Atoms and Kaonic Nuclei

Non-mesonic absorption K - NN  YN International Workshop on Hadronic Atoms and Kaonic Nuclei

13 Schematic side view of the KLOE detector with AMADEUS components added: e+e+ e-e- K-K- K+K+ KLOE International Workshop on Hadronic Atoms and Kaonic Nuclei

KLOE CDC  = ± Lambda invariant mass, using existing KLOE data (O. Vazquez Doce) M inv = 1115,723 ± stat (MeV/c 2 ) PDG: M Λ = 1115,683 ±0.006 stat ±0.006 syst (MeV/c 2 ) systematic dependents on momentum calibration, has to be evaluated using 2-body decays: K ± → μ ± ν and K ± → π ± π 0 International Workshop on Hadronic Atoms and Kaonic Nuclei

KLOE calorimeter KLOE calorimeter International Workshop on Hadronic Atoms and Kaonic Nuclei

Reconstructed K s mass Photon energy resolution  (E)/E = 5.7%xE(GeV) -1/2 time resolution  t/t = 54 [ps]xE(GeV) -1/2 K s  o  o, with  o  International Workshop on Hadronic Atoms and Kaonic Nuclei

Neutron detection efficiency Threshold at 1 MeV Threshold at 3 MeV MC simulation, confirmed with measurements at TSL (Uppsala International Workshop on Hadronic Atoms and Kaonic Nuclei

KLOE International Workshop on Hadronic Atoms and Kaonic Nuclei

KLOE International Workshop on Hadronic Atoms and Kaonic Nuclei

half-toroidal cryogenic target cell 1 st inner-layer of scintillating fibre fiber size: 1x1mm 2 2 nd inner-layer of scintillating fibre fiber size: 1x1mm 2 three outer-layers of scintillating fibre fiber size: 1x1mm 2 AMADEUS setup Low-mass cryogenic gas target cell: T = 10 K P = 1.0 bar Rin = 5 cm Rout = 15 cm L = 20 cm International Workshop on Hadronic Atoms and Kaonic Nuclei

The AMADEUS trigger system Cilindrical layer of scintillating fibers surrounding the beam pipe to trigger K + K - in opposite directions Readout to be done by SiPM Inner tracker (eventually, a first tracking stage before the DC) Target ( A gaseous He target for a first phase of study) Trigger (1 or 2 layers of ScFi surrounding the interaction point) target Trigger system ScFi + SiPM readout K+K+ K-K-  A. Scordo International Workshop on Hadronic Atoms and Kaonic Nuclei

Sketch of the AMADEUS setup International Workshop on Hadronic Atoms and Kaonic Nuclei

View in beam direction Cryo target cell Beam pipe:  = 60 mm, thickness = 0.25 mm made of BeAl alloy Kaon trigger International Workshop on Hadronic Atoms and Kaonic Nuclei

AMADEUS setup II full toroidal cryogenic target cell vacuum chamber thin-walled beam pipe 2 outer-layer of scintillating fibre fiber size: 1x1mm 2 kaon trigger: 2 inner-layer of scintillating fibre fiber size: 1x1mm 2 International Workshop on Hadronic Atoms and Kaonic Nuclei

Tracking device: TPC-GEM or 3-4 C-GEMs Target system: cylindrical cryogenic cell in vacuum chamber Kaon trigger: Scint. fibers with SiPMs 25 AMADEUS setup – phase II

inner tracker FEE AMADEUS setup – phase II Cylindrical GEMs International Workshop on Hadronic Atoms and Kaonic Nuclei

Beam-pipe solutions International Workshop on Hadronic Atoms and Kaonic Nuclei

Number of charged kaon pairs Number of charged kaon pairs N = L  b = 2.9 × 10 9 K - 2 fb -1 = 2 × cm -2 integrated luminosity 0.49 branching ratio for K ± Total number of produced charged Kaon pairs for L = 2 fb -1 1 barn = cm 2 1 femtobarn = barn = cm 2 3 × cm 2  production cross section International Workshop on Hadronic Atoms and Kaonic Nuclei

Number of events for the channel: Number of events for the channel: K He  (K - ppn) + n with (K - ppn)   +d Assumptions: 20% stopped kaons Y = (K - ppn) formation BR for decay channel = 10% (with   p +  - )  For an integrated luminosity of 2 fb -1 : N = 3 x 10 9 x 0.2 (stops) x 5 x (Y) x 0.1 (BR) = ev Detection efficiency for charged particles (40%)  ev Detection efficiency for neutrons (30%)  ev for which both missing and invariant mass can be reconstructed International Workshop on Hadronic Atoms and Kaonic Nuclei

Beam time request Beam time request 2 fb -1 of integrated luminosity with He 4 target in order to study the tribaryon (S=-1) 2 fb -1 of integrated luminosity with He 3 target in order to study the dibaryon (S=-1) overall integrated luminosity of 4 fb -1 With the luminosity upgrade of DA  NE, the machine should deliver at least 500 pb -1 /month, which means that the overall AMADEUS Phase-1 program could be completed in about 8 months International Workshop on Hadronic Atoms and Kaonic Nuclei

 AMADEUS R&D, construction and tests the R&D for AMADEUS are ongoing, construction, assembly and tests have to be finished 2010/11  roll-in of AMADEUS roll-in 2011/12 (end of KLOE step 0)  AMADEUS data taking for an integrated luminosity of about 4 fb -1 AMADEUS time schedule AMADEUS time schedule International Workshop on Hadronic Atoms and Kaonic Nuclei

Conclusion Conclusion The goal of AMADEUS is to perform a complete measurement - formation and decay processes - of di - and tri-baryon antikaon- mediated bound nuclear systems in helium-3 and helium-4. It will contribute to a definite answer of the existence of antikaon-mediated bound nuclear systems in light systems. The antikaon – nucleon/nucleus interaction will be studied in detail with AMADEUS. International Workshop on Hadronic Atoms and Kaonic Nuclei