The SIDDHARTA experiment kaonic hydrogen and deuterium Xray

The SIDDHARTA experiment: kaonic hydrogen and deuterium X-ray spectroscopy T. Ishiwatari Stefan Meyer Institut, Vienna, Austria SIDDHARTA Collaboration Silicon Drift Detector for Hadronic Atom Research by Timing Applications T. Ishiwatari LNF- INFN, Frascati, Italy SMI- ÖAW, Vienna, Austria IFIN – HH, Bucharest, Romania Politecnico, Milano, Italy MPE, Garching, Germany PNSensors, Munich, Germany RIKEN, Japan 9. Oct. 2007, XII HADRON 07 Univ. Tokyo, Japan XII International Conference on Hadron Spectroscopy - Hadron 07 /23

Kaonic atom X-rays and KN scattering lengths Difficulty Shift ( ) and width ( ) of K-p and K-d gives isospin dependent KN scattering lengths(a 0 and a 1) These scattering lengths provide Low-energy SU(3) QCD: SU(3) chiral symmetry, KN s-term, nature of L(1405), S 0 ( 3115 ) S + (3140) T. Ishiwatari 1. High-background in kaon beams 2. Small X-ray yields (a few% K-p, below 1% K-d) 3. Precise determination of X-ray energy and width X-ray detector with 1. high background rejection, 2. large-area, 3. good resolution in energy and time XII International Conference on Hadron Spectroscopy - Hadron 07 2

Experimental results of kaonic atoms Results of kaonic hydrogen Repulsive shift 2 D No data 3 He No data 4 He Large shift Small shift Error on K-p is still large! Accuracy of a few e. V for K-p, First measurement for K-d (as well as 4 He, 3 He) are badly needed! T. Ishiwatari 1000 800 Kp. X 600 Izycki et al, 1980 Attractive shift attractive DEAR 400 200 0 -500 Bird 1983 1 H repulsive Davies New exp. width 1 s [e. V] Katom Old exp. 0 shift 1 s [e. V] 500 Phys. Rev. Lett. 94, 212302 (2005) XII International Conference on Hadron Spectroscopy - Hadron 07 3

DEAR experiment at DAFNE e+e- collider optimized to produce f-meson at rest (1. 020 Ge. V) DEAR T. Ishiwatari K- beam at DAFNE 1. Monochromatic 2. Low-energy 3. No hadronic background XII International Conference on Hadron Spectroscopy - Hadron 07 4

DEAR experimental setup APD Cryo-Cooler TMP CCD Electronics Kaon Monitor Cryo. Tiger CCD Cooling 16 CCD 55 -30 (EEV) Vacuum Chamber T. Ishiwatari -1242 x 1152 pixels - pixel size 22. 5 x 22. 5 mm CCD Pre-Amplifier - total area 7. 24 cm 2 per chip - depletion depth ~30 mm - read-out time 1 min. CCD 55 -Chips - energy resolution ~150 e. V @ 6 ke. V - temperature at 165 K XII International Conference on Hadron Spectroscopy - Hadron 07 5

CCD X-ray detector X-ray events 1 and 2 pixel events Charged particles large pixel events background suppression by pixel analysis T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 6

K-p energy spectrum by DEAR CCDs G. Beer et al. , PRL 94, 212302 (2005) T. Ishiwatari et al. , NIMA 556(2006)509 DEAR results S/N~1: 70 Pa rts of M IP s ~1 , 2 pi xe ls X-ray events X-rays : 1, 2 pixels MIPs : ~ 8 pixels, Some MIPs: ~ 1, 2 pixels �background events on X-ray spectra �Timing needed! = - 193 ± 37 (stat. ) ± 6 (syst. ) 1 s = T. Ishiwatari e. V 249 ± 111 (stat. ) ± 30 (syst. ) e. V XII International Conference on Hadron Spectroscopy - Hadron 07 7

SIDDHARTA experiment (LNF, Italy) Silicon Drift Detectors for Hadronic Atom Research by Timing Application New SDDs specially designed for SIDDHARTA T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 8

Comparison of X-ray detectors used for kaonic X-ray experiments SDD Si(Li) T. Ishiwatari Experiment Kp. X Detector Si(Li) Area [mm 2] Thickness DEAR E 570 CCD SDD 200 724 100 [mm] 5 0. 03 0. 30 D E (FWHM) [e. V] 410 170 185 D t (FWHM) [ns] 290 - 430 T. Ishiwatari NIMA in printing XII International Conference on Hadron Spectroscopy - Hadron 07 9

Triple coincidence technique e+ K+ Triple coincidence: SDDX * Scint. K r SDD to r to illa int Target Sc X-ray K- illa int Φ K+ + K - Sc F S/N =1: 70 (CCD) 10: 1 (SDD) for kaonic Hydrogen T. Ishiwatari e- XII International Conference on Hadron Spectroscopy - Hadron 07 10

Temperature 22 K Pressure max. 5 bar 216 SDDs with 1 cm 2 per SDD Side wall: Kapton 75 µm Kaon entrance Window: Kapton 150 mm T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 11

SDDs electronics Cryogenic target cell Kaon entrance window T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 12

SIDDHARTA Setup on DAFNE SIDDHARTA Kaon monitor T. Ishiwatari focusing quads XII International Conference on Hadron Spectroscopy - Hadron 07 lead shield 13

SIDDHARTA: Schedule • Tuning of setup / optimization 100 pb-1 • Precision measurement of kaonic hydrogen 400 pb-1 • Measurement of kaonic deuterium 600 pb-1 • Further options: Kaonic helium studies (3 He and 4 He) T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 14

Monte Carlo simulation background suppression W/o coincidence MIPs (e+/e-) in SDD Background suppression >103 Kaon decays With coincidence of K+, K-, X-ray Signal rate ~ 2. 2 x 10 -3 /s 130 /d (duty cycle=2/3 of d. ) Energy (ke. V) Asynchronous background (e-, e+) : negligible Synchronous background (K-p reaction, kaon decay) dominant T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 15

Energy spectra in SIDDHARTA (Monte Carlo) Kaonic deutrium Kα Kβ Kaonic hydrogen Kg, . . . S/N=1: 1 S/N=10: 1 Energy (ke. V) K-p: ε 1 s = 193 e. V, Γ 1 s = 249 e. V, Y(Kα )=2% precision: ε 1 s ± 3 e. V Γ 1 s ± 5 e. V K-d: ε 1 s = 325 e. V, Γ 1 s = 630 e. V, Y(Kα )=0. 2% precision: ε 1 s ± 18 e. V Γ 1 s ± 45 e. V Signal rate ~ 2. 2 x 10 -3 /s 30 days data taking 130 /d (duty cycle=2/3 of d. ) XII International Conference on Hadron Spectroscopy - Hadron 07 T. Ishiwatari 16

Expected results in SIDDHARTA Shift and width of kaonic hydrogen 1000 400 Kp. X SIDDHARTA DEAR 200 0 -500 T. Ishiwatari Izycki et al, 1980 M. Iwasaki et al, 1997 Bird et al, 1983 600 Kp. X (KEK) Davies et al, 1979 width 1 s [e. V] 800 0 shift 1 s [e. V] XII International Conference on Hadron Spectroscopy - Hadron 07 500 17

Tests of vacuum chamber and target Leak check, pressure tests, Power consumption tests, etc. have been performed. burst pressure ~ 3. 5 bar T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 18

Microscopic tests T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 19

SDD Spectroscopy test T. Ishiwatari w 49/s 01 w 45/s 03 w 40/s 01 Performance tests of each SDD are done with an Fe source. The average of the energy resolution is ~140 e. V. XII International Conference on Hadron Spectroscopy - Hadron 07 20

SDD test at BTF Back rejection factor at 50 Hz SDD time resolution Dt(FWHM)=720 ns Counts/10 ch/sec No Trigger (without coincidence) Trigger (With coincidence) ADC [ch] T. Ishiwatari TDC [ch] XII International Conference on Hadron Spectroscopy - Hadron 07 21

DAY-1 configuration: mini SIDDHARTA SDD tests with kaon atom X-rays (Nov. and Dec. 2007) Install on “KLOE” I. P. New beam pipe New beam technique Reduced X-ray detection system: 8 -12 SDDs First step: Kaonic nitrogen (and 4 He) Kaonic nitrogen: 4000 X-ray events in ~3 days [30 pb-1] Performance tests of SDDs, Check background suppression T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 22

SIDDHARTA plans 2008: 1) ~ e. V level precision measurement of kaonic hydrogen (400 pb-1); 2) first measurement of kaonic deuterium (600 pb-1) 3) Kaonic helium measurement (He 3 and He 4) Under study: 4) Kaon mass precision measurement at the level of 10 ke. V 5) Other light kaonic atoms measurement (Li, Be…); 6) Investigate the possibility of the measurement of other types of hadronic exotic atoms (sigmonic hydrogen ? ) T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 /23

Summary DEAR finished successfully: most precise data on KH shift and width up to now Theoretical studies continue SIDDHARTA is well under way: precison measurements on KH, KD, … T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 24

Thank you very much T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 25

X-ray transition energies (e. m. ) Kaonic hydrogen Kaonic deuterium T. Ishiwatari (SMI) Kaonic 3 He T. Ishiwatari Kaonic 4 He XII International Conference on Hadron Spectroscopy - Hadron 07 26

Kaonic hydrogen With a 0, a 1 for the I=0, 1 S-wave KN scattering lengths in the isospin limit (md = mu), m being the reduced mass of the K-p system, and neglecting isospin-breaking corrections: Deser-type formula „By using the non-relativistic effective Lagrangian approach a complete expression for the isospin-breaking corrections can be obtained; in leading order parameter-free modified Deser-type relations exist and can be used to extract scattering lengths from kaonic atom data“ (Meißner, Raha, Rusetsky, 2004) T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 27

Kaonic deuterium For the determination of the isospin dependent scattering lengths a 0 and a 1 the hadronic shift and width of kaonic hydrogen and kaonic deuterium are necessary Theoretical procedures are needed to connect the observables with the isospin-dependent scattering lengths T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 28

K-p and K-d atom X-rays K-p (K-d) e. m. bound kaonic atoms Bohr radius ~80 fm, binding energy ~9 ke. V Kaonic atom e. m. energy of K line (e. V) hydrogen 6479 200 250 deuterium 7820 325* 630* X-ray Yield Kα ~1 -3 % ~0. 2 %** *) A. N. Ivanov, M. Cargnelli, M. Faber, H. Fuhrmann, V. A. Ivanova, J. Marton, N. I. Troitskaya, J. Zmeskal, Eur. Phys. J. A 23 (2005) 79 **) Estimated value T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 29

DEAR – Comparison with theory B. Borasoy, R. Nißler and W. Weise, Phys. Rev. Lett. 94, 213401 (2005) T. Ishiwatari A. N. Ivanov et al. , Eur. Phys. J. A 21 (2004) 11 J. Phys. G 31 (2005) 769 Eur. Phys. J. A 25 (2005) 329 XII International Conference on Hadron Spectroscopy - Hadron 07 30

Silicon Drift Detector high energy resolution at fast shaping times, due to the small anode capacitance Small capacitance electrode type anode cathode GND Si(Li) SDD Q = CV = ( S / d ) V UIR UOR UBACK T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 31

T. Ishiwatari XII International Conference on Hadron Spectroscopy - Hadron 07 32