Probing Strong InteractionProbing Strong Interaction--

the SIDDHARTA experimentthe SIDDHARTA experimentby Johann Zmeskalby Johann Zmeskal

SMI, ViennaSMI, Vienna

PANIC11PANIC11PANIC11PANIC11The 19The 19thth Particle and Nuclei International ConferenceParticle and Nuclei International Conference

July 24 July 24 –– 29, 201129, 2011

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LNF‐ INFN Frascati ItalySIDDHARTA collaborationSIDDHARTA collaboration

LNF INFN, Frascati, ItalySMI‐ ÖAW, Vienna, Austria

IFIN – HH, Bucharest, RomaniaP lit i Mil It lPolitecnico, Milano, ItalyMPE, Garching, Germany

PNSensors, Munich, GermanyyRIKEN, Japan

Univ. Tokyo, JapanVictoria Univ , Canada

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Victoria Univ., Canada 

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OutlineOutline

• Introduction• Motivation• Motivation• SIDDHARTA setup• Measuring principle• Results of kaonic heliumResults of kaonic helium• Results of kaonic hydrogen• SIDDHARTA‐2, kaonic deuterium• Summary

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Summary

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Forming  “exotic”  atomsForming  “exotic”  atoms

“normal” hydrogen “exotic”  (kaonic)  hydrogen

n=1 1n~25

p

n=1n=2

e‐ X‐rayeK‐ K‐

X‐ray

2p  → 1sK transition

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Kα transition

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Cascade processesCascade processesStark‐mixingl=0 1 2 n-1n

~ 25

external Auger effectexternal Auger effectchem. de‐excitation

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Coulomb de‐excitation

X‐ray radiation

2

ay a ia io

1 observable hadronicΓ1s

Kα

shift and broadening1s

ε1s

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XX‐‐ray transitions to the 1s stateray transitions to the 1s state

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MotivationMotivationExotic (kaonic) atoms – probes for strong interaction

hadronic shift ε1s and width Γ1s directly observableexperimental study of low energy QCD. Testing chiral symmetry breaking in systems with strangeness 

Kaonic hydrogen K i l t ti t ith tKp simplest exotic atom with strangenessscattering lengths, no extrapolation to zero energyprecise experimental data important/missingkaonic deuterium never measured beforekaonic deuterium never measured before

Information on Λ(1405) sub‐threshold resonanceresponsible for negative real part of scattering amplitude atresponsible for negative real part of scattering amplitude at thresholdimportant for the search for  the controversial „deeply bound kaonic states” (KEK, GSI, DAΦNE, J‐PARC)

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Determination of the isospin dependent KN scattering lengths PANIC11

LowLow‐‐energy Kenergy K‐‐N systemsN systemsChiral perturbation theory, which was developed forπp, ππ is not applicable for K‐N systems

Non‐perturbativeCoupled ChannelsCoupled Channels approach based on 

Chiral SU(3) Dynamics

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1D‐2:  Jiri MaresPANIC11

Kaonic hydrogen atoms at DAKaonic hydrogen atoms at DAΦΦNENE

e+‐e‐collider

AAccu.

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DADAΦΦNE parametersNE parameters• operates at the centre‐of‐mass energy of the Φmeson

mass   m = 1019.413 ± .008 MeVwidth Γ = 4 43 ± 06 MeVwidth Γ  4.43 ± .06 MeV

• produced via e+e‐ collision with( + Φ) 5 bσ(e+e‐ → Φ) ~ 5 μb

• average luminosity   L = 5 x 1032 cm‐2 s‐1→Φ production rate  2.5 x 103 s‐1

• Φ decays at rest to about~ 50% K+K‐→monochromatic kaon beam (127 MeV/c)

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monochromatic kaon beam (127 MeV/c)

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SIDDHARTA setupSIDDHARTA setup

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Lightweight  cryogenic  target  cellLightweight  cryogenic  target  cell

working T  22 Kworking P  1.5 bar         

Alu gridAlu‐grid

Side wall:Kapton 50 μm

Kaon entranceWindow:Kapton 75 μm

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SIDDHARTA target SIDDHARTA target ‐‐ detectordetector

Advanced Seminar Series Particles and Interactions13PANIC11

Development of large area SDDsDevelopment of large area SDDs

SDD window frame(pure Al 99.999%)

flexible Kaptonboards

pre‐amplifierpre‐amplifierboard

HV+LV distributionb dboard

FP‐6 EU programme:HadronPhysics

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y

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Excellent energy resolutionExcellent energy resolution

FWHM = 150 eV@ 6keV

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Energy [eV]

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Detectors used for KDetectors used for K‐‐p experimentsp experiments

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Sketch of the SIDDHARTA setupSketch of the SIDDHARTA setup

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φφ productionproduction

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KaonKaon pair detectionpair detection

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“triple” coincidence method“triple” coincidence method

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Measuring  principleMeasuring  principle

+−+− +→→+ KKee φ SDDsK‐

Production of φ at restat DAΦNE

+→→+ KKee φ

degrader

φe‐ e+

Scintillators

φ

K+

e‐ e+

K

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T i l i id

Measuring  principleMeasuring  principle

+−+− +→→+ KKee φ SDDs

Triple coincidence

K‐

Production of φ at restat DAΦNE X‐ray

+→→+ KKee φ

degrader

Scintillators

φ

K+

e‐ e+

K

ts / 100 ns

coun

22SDD timing [μs]

Data taking scheme at DAData taking scheme at DAΦΦNENE

K+K- pairs producedat DAΦNEat DAΦNE

Production data

−K SDDs

degrader

−e +eφ

g

23+K

Scintillators

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Data taking scheme at DAData taking scheme at DAΦΦNENE

“X‐ray  tube”  datataken with “beam” ONa e i ea O

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“X t b ” d t t k

SDD XSDD X‐‐ray energy spectraray energy spectra“X‐ray tube” data taken

destimated systematic error ~ 3‐4 eV

0eV

ounts / 30

co

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SDD XSDD X‐‐ray energy spectraray energy spectra

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KaonicKaonic heliumhelium‐‐3 energy spectrum3 energy spectrum

eV)(5.3)(4.20.6223exp sysstaE ±±=

QED value: E = 6224 6 eVK-3He (3d-2p)

eV)(4)(22 sysstaE ±±−=Δ

QED value: Eem= 6224.6 eV

eV)(4)(222 sysstaE p ±±=Δ

..exp2 mep EEE −=Δ

Ti KaK-C K-O K-N

First observation of K‐3He X‐rays

arXiv:1010.4631v1 [nucl-ex], PLB697(2011)19927

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eV)(4)(35 sysstaE ±±+=Δ

Comparison Comparison kaonickaonic 33He and He and 44HeHe

V)(4)(22EΔ

eV)(4)(352 sysstaE p ±±+=Δ

eV)(4)(222 sysstaE p ±±−=Δ

K-3He (3d-2p)

K-4He (3d-2p)

K-3He (3d-2p)

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Kaonic helium resultsKaonic helium results

29calibration under control within several eV

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KaonicKaonic hydrogen hydrogen 

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SDD SDD timing timing vs. vs. energyenergy

KKaon

BG

Kaon gateBackground gateg g

(asynchronous background)

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Fitting  procedureFitting  procedure

Hydrogen

simulttaneous

Deuterium

s   fit

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KK‐‐p spectrum after BG subtraction p spectrum after BG subtraction 

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XX‐‐ray transitions to the 1s stateray transitions to the 1s state

Kβ

K

KαKhigh

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KK‐‐p spectrum after BG subtraction p spectrum after BG subtraction 

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“repulsive” shift“repulsive” shift

X‐ray energy reduced (shift sign is negative)y gy ( g g )

2p

1s

Coulomb

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Kaonic hydrogen resultsKaonic hydrogen resultsε 283 ± 36(stat) ± 6(syst) eVε1s = ‐283 ± 36(stat) ± 6(syst) eVΓ1s =  541 ± 89(stat) ± 22(syst) eV

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W.Weise, ei e,LEANNIS meeting July 2011

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WWeise LEANNIS meeting July 2011W.Weise, LEANNIS meeting July 2011

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Kaonic deuterium dataKaonic deuterium datafit for shift:  about 500 eV 

KC(6‐5)

KC (5‐4)width: about 1000 eV  

(6 5) 

KO

KN(6 5)

KO(6‐5)

l

KC (7 5)

KO(7‐6)

C(6‐5)

KC (6‐4)

KAl (8‐7)

(7‐5)KO(9‐7)

KTi (11‐10)

Cu Kα KAl 

(7‐6)KN(5‐4)

KAl (10‐8)

Pb  Lβ

Kd KcomKd 

KαKα

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SIDDHARTASIDDHARTA‐‐2 for kaonic deuterium2 for kaonic deuterium

•• new target designnew target design•• new target design new target design 

•• new SDD arrangementnew SDD arrangement

••more cooling powermore cooling power

•• improved trigger schemeimproved trigger scheme•• improved trigger schemeimproved trigger scheme

•• shielding and antishielding and anti‐‐coincidencecoincidence

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Kaonic deuterium Kaonic deuterium –– MC simulationsMC simulationsmodel inputshift = - 660 eVwidth= 1200 eV

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energy  [keV]

SIDDHARTA setup was working with 144 SDDsSummarySummary

SIDDHARTA  setup was working with 144  SDDs 

Kaonic X‐ray spectra measured with several gaseoustargets:K‐p: provided the  most precise values (submitted to PLB: arXiv:1105.3090)(submitted to PLB: arXiv:1105.3090)

K‐d: first exploratory measurement small signal (large width)g g

K‐3He: first‐time measurement (PLB 697(2011)199)

K‐4He:measured in gaseous target for the firstK He:measured in gaseous target for the first time (PLB 681(2009)310)

planning for “SIDDHARTA 2”→ improved

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planning for “SIDDHARTA‐2” → improvedtechnique to (re‐)measure K‐d

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Supported  bySupported  by

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Kaonic hydrogen resultsKaonic hydrogen results

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Kaonic hydrogen resultsKaonic hydrogen results

SIDDHARTA

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