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Low- energy anti- kaon nucleon and nuclei interactions. J. Marton Stefan Meyer Institute Austrian Academy of Sciences , Vienna. LEANNIS. Scope. LEANNIS.
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Low-energy anti-kaonnucleonandnucleiinteractions J. Marton Stefan Meyer Institute Austrian AcademyofSciences, Vienna LEANNIS 19th IUPAP Conference on Few Body Problems
Scope LEANNIS A kindofoverview on open problemsandcurrentandfutureattemptstosolvethem (here I wanttofocus on dedicatedexperiments) Topics whichare in thescopeofthe LEANNIS network ofthe EU project HadronPhysics2 Few Body problemsinvolvingstrangeness: Specifictalks on theoreticalapproachesandexperiments (experiments: M. Iio, O. VazquesDoce, S. Okada, Y. Fujiwara) atthis Conference 19th IUPAP Conference on Few Body Problems
Content • Motivation fornew (experimental) studies • Exotic (hadronic) atoms – thresholddata • Kaonic hydrogen isotopes (strong interactioneffect on 1s) • Kaonichelium isotopes (strong interaction on 2p) • Searchforboundstrangenuclearsystems (K-pp, K-ppn …) • K- stopped • K- in-flight • pp collisions • New ideas • Status and Outlook 19th IUPAP Conference on Few Body Problems
Motivation fornewstudies Interestingquestion: Two-pole structure?? Λ(1405) & Λ(1420) and theirimpact • The low-energykaon-nucleoninteractionisneither simple nor well understood • Central importance for the physics of strong interaction has the dynamics driven by chiral symmetry breaking in low-energy QCD • Problems arise from the existence of hyperon resonances like the Λ(1405) • Problems arise also due to 2 nucleon K-absorptionpossiblyimitatingboundstates • The development of reliable theories suffers from the lack of precision data on the observables at threshold (e.g. shift/width of kaonic atoms) 19th IUPAP Conference on Few Body Problems
Sourcesof experimental information on thelowenergy (anti)kaon-nucleoninteraction • Kaon-protonscatteringdata (olddatawith large errors, abovethreshold extrapolation) • πΣ massspectrum • Thresholddecayratios • X-raydataoflightkaonicatoms (K-p, K-d, K-He): seetalksby S. OkadaandIioatthisconference • Kaonic hydrogen increaseprecision, thresholddataimportantinputfortheory • Kaonicdeuterium first experimental studies, thresholddataimportantinputfortheory • Kaonic helium-4 2p shiftsmall (KEK 570), rules out „superstrong“ antikaonnuclearinteraction • Kaonic helium-3 first experimental studies • Reliabletheoryhastocopetheseinformations 19th IUPAP Conference on Few Body Problems
Kaonic hydrogen anddeuterium Strong interactioneffects manifest in hadronicshiftandwidthofthe 1s state, i.e. deviationfromtheelectromagneticvalueofthe 1s stateandbroadening due toabsorption whichcanbecalculatedwith an accuracyofabout 1eV bysolvingthe Klein-Gordon (KG) equationandtakingintoaccountvacuumpolarization (VP) and final size (FS) effect. Strong interactioneffect on 2p stateisweak (meV) andexperimentallyundetermined, but hassevereconsequencesforthe x-rayyield 19th IUPAP Conference on Few Body Problems
X-rayyields Strong interaction on 2p level2p widthΓ2p Γ2plimitsyield - but ispoorlyknown K-p K-d M. G. Raisiand S.Z. Kalantari, PRA 79 (2009) 012510 19th IUPAP Conference on Few Body Problems
Thresholddata on kaonic hydrogen • KpX@KEKsolvedthe so-called"kaonic hydrogen puzzle" interactionis repulsive • Precision limited (e.g. error bar ofwidth > 50%) • Most precisevaluesforshiftandwidthfromDEARexperiment (CCDs) • But still precision limited • shift vs. width (1 σerrors) seebelow DEAR (2005) 1s = - 193 ± 37 (stat.) ± 6 (syst.) eV 1s = 249 ± 111 (stat.) ± 30 (syst.) eV aK-p = (-0.468 ± 0.090 ± 0.015) + i(0.302 ±0.135± 0.036) fm KpX (1998) 1s = - 323 ± 63 (stat.) ± 11 (syst.) eV 1s = 407 ± 208 (stat.) ± 100 (syst.) eV aK-p = (-0.78 ± 0.15 ± 0.03) + i(0.49 ±0.25± 0.12) fm usingDeser-Trueman (i.e. lowest order) 19th IUPAP Conference on Few Body Problems
Close interconnectionbetweenexperimentandtheory • Lowest order: Deser-Trueman • NLO: Isospinbreakingcorrections U.-G- Meißner, U. RahaandA. Rusetsky, Eur. Phys.J. C35 (2004) 349 19th IUPAP Conference on Few Body Problems • Example K-p: extractionofscatteringlengthsfromexperimentadata Even morechallengingisthecaseofkaonicdeuterium
KN interaction at threshold K-p: repulsive at threshold, attractive below threshold threshold real part Imag. part DEAR data B. Borasoy, R. Nißlerand W. Weise, Phys. Rev. Lett. 94, 213401 (2005) 19th IUPAP Conference on Few Body Problems
New experiments -- new (x-ray) detectors • Silicon Drift Detectorswith large activearea activearea 100 mm2 • Excellentenergyresolution, timing • 2 different typesforexoticatomresearch • SDD withexternal FET (commercialproduct, KETEK) systemstudied: K-4He (E570/KEK), K-3He (E17/J-PARC) • SDD with on chipintegrated FET SIDDHARTA (JRA10/EU-FP6) systemstobestudied:K-p, K-d …. 19th IUPAP Conference on Few Body Problems
Kaonicnuclearclusters ? Prototype system K-pp 19th IUPAP Conference on Few Body Problems
Recentdevelopments in theory Faddeevcalculations See talk by N. Shevchenko atthis Conference Variationalcalculations Binding energy: 20 - 50 MeV Decaywidth: 40 - 100 MeV T. Yamazaki, Y. Akaishi PRC 76 (2007) 045201 A. Dote, T. Hyodo, W. Weise NPA 804 (2008) 197 A. Dote, T.Hyodo, W. Weise PRC 79 (2009) 014003 Binding energy: 55 – 70 MeV Decaywidth: 95 – 110 MeV N. Shevchenko, et al. PRL 98 (2007) 082301 N. Shevchenko et al. PRC (2007) 044004 Y. Ikeda, T. Sato PRC 76 (2007) 035203 19th IUPAP Conference on Few Body Problems
K-pp: Comparisonexperiment-theory VC … Variationalcalculations AY02 … VC AkaishiandYamazaki PL B535 (2002) 70 FC … Faddeevcalculations Not a clearpicture VC OBELIX, NPA789 (2007)222 FINUDA PRL94 (2005) 212303 AY02 AY02 FC VC FC OBELIX, NPA789 (2007)222 FINUDA PRL94 (2005) 212303 DISTO, preliminary Proc. EXA/LEAP09, Hyp. Int. in print DISTO, preliminary Proc. EXA/LEAP09, Hyp. Int. in print
Production of antikaon-mediated bound nuclear cluster(KNC)? • stopped K- reactions on light nuclei • in-flight K- reactions • protons on proton (or light nuclei) • heavy ion collisions • antiproton induced reactions • dedicated experiments • exclusive measurement 19th IUPAP Conference on Few Body Problems
Search for kaonic nuclear clusters with AMADEUS at LNF See talk by O. Doce Vazquez AMADEUS collaboration: 114 scientists from 13 Countries and 33 Institutes Searchforkaonicnuclearsystems with S-1 using K- stopped in helium gas and employingthemodified KLOE apparatusat DAΦNE/LNF forexclusiveexperiments lnf.infn.it/esperimenti/siddharta and LNF-07/24(IR) Report on lnf.infn.it web-page (Library) 19th IUPAP Conference on Few Body Problems
K-pp production in pp reactionwith FOPI p on hydrogen targetat 3 GeV Experimental searchforthemost simple KNC – the prototype systemppK- with • missingmassspectroscopy • invariant massreconstruction • Presentlytakingdataat GSI 19th IUPAP Conference on Few Body Problems
neutron K-pp cluster reaction decay Charged particles decay p L Search for K-pp bound state with Missing mass spectroscopy and Invariant mass reconstruction p- p Search for K-pp in flight (E15@J-PARC) 3He (liquid) • 3He(K-,n) reaction, experiment in connection with E17 K- Missing mass spectroscopy by n detection Invariant mass reconstruction 19th IUPAP Conference on Few Body Problems
New ideas Proposed by P.Kienle(*), T.Yamazaki and W.Weise(**) (*) Int. Jour. Mod. Phys. A 22 (2007)365 (**) arXiv:nucl-th/0507058 v1 (2005) IdeasupportedbyObelixdata Searchforkaonicnuclearclusters S-2 (double strangeness) Production via antiprotonannihilationproposed, EB> 100 MeV 19th IUPAP Conference on Few Body Problems
New experiments? • Requirementsforpbarannihilationstudiesatrest: (J. Zmeskal et al. Proc. EXA08, Hyp. Int. In print) • Low-energypbar beam: AD/CERN, FLAIR/FAIR • Detectorforexclusiveannihilationstudies in nuclei • Start counter – scintillating fibers with Geiger Mode - APD readout • PID – with a TPC - GEM (similar as proposed for PANDA) • For neutral particle detection - a Calorimeter with alternating scintillating fibres – lead layers (KLOE-type) • High statistics 19th IUPAP Conference on Few Body Problems
Status and Outlook New experiments on thresholddata(shift, width) oflightkaonicatomsarerunning (SIDDHARTA@LNF) or in preparation(E17@J-PARC) Thresholddataarecrucialprerequisitesforthetheoreticaldescription (enhancementofthepredictive power for sub-threshold) Challenge: Nature ofΛ(1405) – 2-pole structure? Can oneinvestigatethisquestionexperimentally? Theoreticalstudies on thequestionofkaonicnuclearclustersareongoing (Faddeev, variationalcalculations) Evidenceforexistenceofkaonicnuclearclusters (FINUDA, OBELIX, DISTO, …) New fullyexclusiveexperimentswithvariousreactionsareindispensibleandare in preparation New idea: Kaonicnuclearclusterwith double strangenessproduced in antiprotonannihilation 19th IUPAP Conference on Few Body Problems
No phenomenon is a real phenomenon until it is an observed phenomenon. John Archibald Wheeler If you haven't found something strange during the day, it hasn't been much of a day. (A. Wheeler) Thankyou 19th IUPAP Conference on Few Body Problems
Spare 19th IUPAP Conference on Few Body Problems
Interconnection experiment-theorycont‘d πΣmassspectrumextrapolationfromanalysisofdataabovethreshold (B. Borasoy, R. Nisslerand W. Weise, Eur.J. A25 (2005) 79) K-p threshold Precision thresholddata(SIDDHARTA) will increasethepredictive power • Extrapolation ofsubthresholdbehaviorfrom experimental data 19th IUPAP Conference on Few Body Problems
Experiments • KN thresholdstudiesby x-rayspectroscopy(SIDDHARTA@LNF, E17@J-PARC) • seetalksby S. OkadaandIioatthisconference • Searchfor quasi-boundnuclearsystemswith S=-1 (E549@KEK, DISTO, FOPI@GSI, E15@J-PARC, AMADEUS@LNF) • see talk by O. Doce Vazquez on AMADEUS atthis Conference • Searchfor quasi-boundnuclearsystemswith S-2 (OBELIX, CERN AD, FLAIR) 19th IUPAP Conference on Few Body Problems
ComparisonofchiralandphenomenologicalKN interaction 1405 1420 T. Hyodoand W. Weise, PR C77 (2008) 035204 19th IUPAP Conference on Few Body Problems