Low-energyan,kaonsinterac,onwithnuclei:theAMADEUSchallenge

SMI – STEFAN MEYER INSTITUTE

WWW:OEAW.AC.AT/SMI JMMarch2016

J.MartonStefanMeyerIns,tute(SMI)

Vienna,Austria

Mo,va,on

•  An,kaoninterac,onrepresentsaninterplaybetweenexplicitandspontaneouschiralsymmetrybreaking

•  Strengthofan,kaon-nucleon/nucleiinterac,on

•  Exo,csinthestrangenesssectorΛ(1405)•  Existenceof(dense)baryonicmaRer,boundstates?

•  Roleofstrangenessincompactstars(neutronstars)

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Somesolved/openproblemsinKbarNinterac,on

Solvedproblems:•  Kaonichydrogen:1sstateshiX/widthàessen,alinputfortheorybySIDDHARTA•  Kaonichelium:2pstateshiX(width)

Openissues:•  KbarNinterac,onaRrac,veandabsorp,ve(KbarNpoten,al

aRrac,veandabsorp,veaccordingtotheoryconfirmedbykaonicatoms)–buthowstrong?

•  Boundstates,Λ(1405),kaonicnucleilikeK-pp•  Absorp,onofKbarinnuclei•  Roleofstrangenessincompactstars•  KaonicdeuteriumshiX,width-

K-ninterac,on

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DAΦNE:ΦFactoryofLNF-INFN

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Doubleanularelectron-positroncolliderproducingΦ(1020MeV)resonantly

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DAΦNE:Uniquesourceofan,kaons

•  An,kaons(kaons)fromtheΦvectormesondecay–nearlymonoenerge,c(127MeV/c≈16MeV)

•  ≈50%branchingofthetwo-bodydecayΦàK+K-

•  Lowhadronicbackgroundkaonsource•  Idealforexperimentsonkaonicatomsandlow-energyan,kaoninterac,onsonnuclei(AMADEUS)

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DAFNEcollider:Strangenessnuclearphysics

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AMADEUS

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AMADEUS

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Powerfulcombina,onwiththedetectorsystemofKLOE(96%acceptance)Verygoodperformanceforthedetec,onofchargedandneutralpar,cleintherelevantenergyrange

DAΦNEkaonsource+KLOE

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Subthresholdresonances

KaonscaRering

An,kaonnuclearabsorp,on

An,kaonboundstatesHypernuclearphysics

AMADEUSlaboratoryforlow-energykaonphysics

ConsequencesofstrangenessfordensebaryonicmaRer(neutronstars)?

Kaon/an,kaonscaRering

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Dataatlowmomenta(<100MeV/c)missing

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ThresholddatafromkaonichydrogenàSIDDHARTATheregionbetweenthresholdand≈100MeVàterraincognita

Properties of hadronic resonances

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T.Hyodo,D.Jido,Prog.Part.Nucl.Phys.67(2012)55-98

Λ(1405)one-ortwo-poleobject??PDG,Phys.Rev.D86(2012)

πΣdominant

KbarNdominant

An,kaonabsorp,oninnuclei

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Quasi-boundkaonicnuclei?

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Thepresentknowledgefromexperimentandtheoryiss,llinsufficienttomakeaclearstatementaboutquasi-boundkaonicnuclearsystemsExperimentssofar:FINUDAKEKDISTOFOPIHADESOBELIXJ-PARCE15,E27Future:AMADEUS

Decaywidthsandbindingenergiesfromexperimentandtheory:

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Quanta,veunderstandingopen

StrangenessinNeutronStars?

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Hypernuclearstudies:Neutron-richhypernuclei

•  Neutron-richhypernucleiproducedbystoppedK-

•  Studiesofmesonicandnon-mesonicdecaysàdetec,onofchargedandneutralpar,cles

(e.g.π0spectroscopy)

Examples

PossibleAMADEUSSetup

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Axialmagne,cfield:0.5T

Calorimeter

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98%solidanglecoverage

1MeVthres3MeVthres

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AMADEUSsetup:ExampleK-absorp,onon3He

MCsimula,onoftracksinAdedicatedAMADEUSsetupWitha3Hecryogenictarget.TracksaXerK-reac,onon3He.

Pre-AMADEUSstudieswithKLOEdata

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•  Studyofan,kaoninterac,oninnuclearmaRerfollowingK-absorp,onintheDCgas(orstructurematerials)

•  KLOEdriXchamber(DC)gas:mainly4He(90%4He,10%isobutaneC4H10)

•  0.1%K-stopintheDCgas(MonteCarlo,dataanalysis)

•  EnablesthestudyofK-absorp,onandsearchesforboundstates(e.g.with2s-1hundredsofkaonicclusters)–analysisofΛ/Σ–p,d,tcorrela,ons

•  Analysiscomplicatedduetomaterialmix

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KLOEDriXChamber(DC)

Pre-AMADEUS

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•  AnalysesofKLOEdatacollected2002–2005

•  Specialsetupwithapurecarbon“target”insertedintoKLOE(2012)–gaininsta,s,cs(90pb-1),K-absorp,onincarbon)

•  Inves,ga,onoftopics:•  Λp,Σ0pfrom1NAor2NA(single/doublenucleon

absorp,on),searchforK-pp

•  Λ-dnuclearabsorp,onandsearchforK-ppn,Λ-t

•  Λ(1405)àΣ0π0andΛ(1405)àΣ+π-

•  ΣN/ΛNinternalconversionrates

•  R&Dforop,mizedsetupLEAP2016J.Marton

Dataanalysis:Λ(1116)selec,on

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dE/dx(ADCcounts)-momentum

SelectedprotonsSelectedpions

Mpπ-invariantmassspectrum

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ppK−/K−stop=(0.044±0.009stat+0.004−0.005syst)·10−2 Significance1σ–notsufficienttoclaimppK-observa,on

RecentresultsfromPre-AMADEUS

K-pp?

Lint=1.74s-1

K-stop=3.25108

Summary

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ThededicatedAMADEUSsetupwillprovideapowerfullaboratoryforexperimentalstudiesofan,kaoninducedreac,onsemployinglow-energyorstoppedkaonsreac,ngintargets(feasibilityofac,vetargets,TPC).Staytuned.

ThePre-AMADEUSprogramdemonstratedalreadytheenormouspoten,aloftheKLOEdetectorforstrangenessnuclearphysics.

Thank you for your attention

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Spare

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