1. V.Duk, INR Moscow Quarks-2008, May 23-29 1 OKA Experiment for Studying Rare Kaon Decays Viacheslav Duk, INR Moscow for collaboration

2. V.Duk, INR Moscow Quarks-2008, May 23-29 2 IHEP, Protvino OKA collaboration: IHEP, Protvino INR, Moscow JINR, Dubna

3. V.Duk, INR Moscow Quarks-2008, May 23-29 3 1.Experiments with charged kaons 2.Separated kaon beam at IHEP 3.OKA physics program 4.Current status of the experiment 5.Conclusions Contents

4. V.Duk, INR Moscow Quarks-2008, May 23-29 4 Current and future experiments with kaons In-flight decays Stopped kaons E06 – J-PARC,K+→μνπ 0 E09 – J-PARC, K+ →π + νν NA62 – CERN, K + (talk by Augusto Ceccucci) OKA - IHEP, Protvino, K ± (this talk) E14(KOTO) – J-PARC, K 0 (talk by Mikhail Doroshenko)

5. V.Duk, INR Moscow Quarks-2008, May 23-29 5 Experiments with charged kaons Studying more rare decaysInreasing presicion High intensity beams Separated (“Clean”) beams NA62 OKA how experiment 2 strategies in kaon experiments Strategies are complementary

6. V.Duk, INR Moscow Quarks-2008, May 23-29 6 Separated beams  Low background from inelastic scattering  Absence of trigger effects  Possibility of fixed target program  Complicated channel  Relatively low intensity + –

7. V.Duk, INR Moscow Quarks-2008, May 23-29 7 separated and unseparated beams: complementarity NA62OKA beam Intensity ~10 9 5*10 6 Beam rate800 MHz1.1 MHz Kaons in the beam ~5%~70% Duty cycle30%22% % of kaons decaying in decay pipe 13%9% Kaon decay rate 520 x 10 4 7 x 10 4

8. V.Duk, INR Moscow Quarks-2008, May 23-29 8 RF separated beam at IHEP Panofsky scheme Deflectors: largest possible distance Synchronized em field (3GHz) in deflectors (-1) optics: pions are deflected in opposite directions Beam stopper: absorbe pions Choose momentum: maximal deflection of kaons Protons also absorbed (m p ) 2 /(m π ) 2 ~ 4 kaon deflection proton deflection Nd deflectors are cooled by liquid He, T=1.8K

9. V.Duk, INR Moscow Quarks-2008, May 23-29 9 Physics program at OKA Baseline: ISTRA+ program on a larger statistics The program is being tuned by latest results from NA48/2, NA62, KLOE Main directionsmethod ChPT tests, deviations from SM BR and/or dalits-plot in Kl2,Kl2gamma, Kl3 decays T-odd effectsT-odd asymmetries in 4- body decays Sgoldstino searchK->π π 0 P decay: peak in (P K -P π -P π0 ) 2 distribution exoticaFixed target program ISTRA+: 3%(kaons)*2*10 6 =6*10 4 OKA: 70%(kaons)*5*10 6 =350*10 4 OKA / ISTRA+ ~60

10. V.Duk, INR Moscow Quarks-2008, May 23-29 10 Physics: ChPT tests, deviations from SM Search for tensor and scalar terms K→μνπ 0 (Kμ3) and K→eνπ 0 (Ke3) decays a ISTRA+: ~500K Kμ3 OKA: ~20M Kμ3 Formafactors in Ke3, Kμ3, F v and F A in K→μνγ, K→eνγ

11. V.Duk, INR Moscow Quarks-2008, May 23-29 11 Physics: T-odd effects

12. V.Duk, INR Moscow Quarks-2008, May 23-29 12 Status of the experiment

13. V.Duk, INR Moscow Quarks-2008, May 23-29 13 Status of the experiment

14. V.Duk, INR Moscow Quarks-2008, May 23-29 14 Status of the experiment: separated beam Beamline with RF deflector RF deflector

15. V.Duk, INR Moscow Quarks-2008, May 23-29 15 Status of the experiment: separated beam 1% 7% Kaons in the beam No separator with separator Separator status: commissioned Worked during 2007 test run Cleaning in progress

16. V.Duk, INR Moscow Quarks-2008, May 23-29 16 OKA status: beam spectrometer Beam profile efficiency Beam proportional chambers: 1mm step 20cm X 20cm Threshold Cherenkov counters Beam magnet σP/P ~ 1%

17. V.Duk, INR Moscow Quarks-2008, May 23-29 17 OKA status: active decay volume 11m long Filled with He sandwich veto counters with fiber readout (~300 channels)

18. V.Duk, INR Moscow Quarks-2008, May 23-29 18 OKA status: spectrometer Straw tubes: 9mm tubes 2 layers 140cm x 140cm Drift tubes: 4cm tubes 3 layers 200cm x 200cm

19. V.Duk, INR Moscow Quarks-2008, May 23-29 19 OKA status: electromagnetic calorimeter 3.8cm x 3.8cm cells Resolution 5%/√E ~20 X 0 ~4000 channels

20. V.Duk, INR Moscow Quarks-2008, May 23-29 20  RF separated high energy kaon beam at IHEP, Protvino has been constructed and is being commissioned  First stage of OKA setup has been commissioned  First statistics – November 2008 Conclusions

21. V.Duk, INR Moscow Quarks-2008, May 23-29 21

22. V.Duk, INR Moscow Quarks-2008, May 23-29 22 Spares: separator

23. V.Duk, INR Moscow Quarks-2008, May 23-29 23 Status of the experiment

24. V.Duk, INR Moscow Quarks-2008, May 23-29 24 Status of the experiment

25. V.Duk, INR Moscow Quarks-2008, May 23-29 25 Status of the experiment

26. V.Duk, INR Moscow Quarks-2008, May 23-29 26 K→K→

27. V.Duk, INR Moscow Quarks-2008, May 23-29 27 K→K→