OKA Experiment

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OKA Experiment for Studying Rare Kaon Decays
Status and Prospects
Viacheslav Duk, INR Moscow for collaboration
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IHEP, Protvino
OKA collaboration IHEP, Protvino INR,
Moscow JINR, Dubna
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Contents

1. Experiments with charged kaons
2. Separated kaon beam at IHEP
3. OKA physics program
4. Current status of the experiment
5. Conclusions

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Current and future experiments with kaons
In-flight decays
Stopped kaons
E06 J-PARC,K?µ?p0 E09 J-PARC, K ?p??
NA62 CERN, K (talk by Augusto Ceccucci) OKA
- IHEP, Protvino, K (this talk) E14(KOTO)
J-PARC, K0 (talk by Mikhail Doroshenko)
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Experiments with charged kaons
2 strategies in kaon experiments
Studying more rare decays
Inreasing presicion
High intensity beams
Separated (Clean) beams
how
NA62
OKA
experiment
Strategies are complementary
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Separated beams

• Low background from inelastic scattering
• Absence of trigger effects
• Possibility of fixed target program

• Complicated channel
• Relatively low intensity

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separated and unseparated beamscomplementarity
NA62 OKA
beam Intensity 109 5106
Beam rate 800 MHz 1.1 MHz
Kaons in the beam 5 70
Duty cycle 30 22
of kaons decaying in decay pipe 13 9
Kaon decay rate 520 x 104 7 x 104
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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
• (mp)2 /(mp)2 4

kaon deflection
proton deflection
Nd deflectors are cooled by liquid He, T1.8K
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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 directions method
ChPT tests, deviations from SM BR and/or dalits-plot in Kl2,Kl2gamma, Kl3 decays
T-odd effects T-odd asymmetries in 4-body decays
Sgoldstino search K-gtp p0 P decay peak in (PK-Pp-Pp0)2 distribution
exotica Fixed target program
ISTRA 3(kaons)21066104 OKA
70(kaons)5106350104 OKA / ISTRA 60
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Physics ChPT tests, deviations from SM
K?µ?p0 (Kµ3) and K?e?p0 (Ke3) decays
Search for tensor and scalar terms
aa
Formafactors in Ke3, Kµ3, Fv and FA in K?µ??,
K?e??
ISTRA 500K Kµ3 OKA 20M Kµ3
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Physics T-odd effects
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Status of the experiment
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Status of the experiment
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Status of the experiment separated beam
Beamline with RF deflector
RF deflector
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Status of the experiment separated beam
Kaons in the beam
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No separator
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with separator

• Separator status
• commissioned
• Worked during 2007 test run
• Cleaning in progress

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OKA status beam spectrometer
Beam profile

• Beam proportional chambers
• 1mm step
• 20cm X 20cm
• Threshold Cherenkov counters
• Beam magnet

efficiency
sP/P 1
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OKA status active decay volume

• 11m long
• Filled with He
• sandwich veto counters with fiber readout (300
  channels)

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OKA status spectrometer
Straw tubes 9mm tubes 2 layers 140cm x 140cm
Drift tubes 4cm tubes 3 layers 200cm x 200cm
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OKA status electromagnetic calorimeter

• 3.8cm x 3.8cm cells
• Resolution 5/vE
• 20 X0
• 4000 channels

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Conclusions

• 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

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Thank you!
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Spares separator
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Status of the experiment
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Status of the experiment
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Status of the experiment
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K?
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K?