CERN, 11-5-2009 A. Ceccucci - PowerPoint Presentation

1. CERN, 11-5-2009A. Ceccucci 1NA62: New Opportunities In Rare Kaon DecaysCERN-SPSC-2005-013 SPSC-P-326CERN-SPSC-2007-035 SPSC-M760Bern ITP, Birmingham, Bristol, CERN, Dubna, Ferrara, Fairfax, Florence, Frascati, Glasgow, IHEP, INR, Liverpool, Louvain, Mainz, Merced, Naples, Perugia, Pisa, Rome I, Rome II, San Luis Potosi, SLAC, Sofia, TRIUMF, Turin A. Ceccucci for the NA62 Collaboration:

2. CERN, 11-5-2009A. Ceccucci 2Flavor in the Era of the LHC*The current experimental manifestations of CP-Violation (K and B decays and mixing) are consistent with just one complex phase in the CKM matrix (“Standard Model”) PDG’08Paradigm shift: we should determine the “true” CKM parameters from observables not affected by New Physics (e.g. B tree decays) and measure loop-induced, precisely predictable (SM), FCNC to detect patterns of deviation *CERN Extended workshop, Nov 2005, March 2007, Edited by R. Fleischer, T. Hurth and M.L. Mangano EPJ C, 57, Vol 1-2, Sept 2008 “[These articles] confirm that flavour physics is an essential ingredient in the future of high-energy physics”

3. CERN, 11-5-2009A. Ceccucci 3Cristopher Smith @ CKM ‘08 K → pnn : Theoretically Pristine and Almost Unexplored [1] J.Brod, M.Gorbahn, PRD78, arXiv:0805.4119 [2] AGS-E787/E949 PRL101, arXiv:0808.2459  [3] c.f. CKM 08 procs.[4] KEK-E391a PRL 100, arXiv:0712.4164 Proposed: KOTO (E14) J-PARC

4. Kaon Rare Decays and NP (courtesy by Christopher Smith) CERN, 11-5-2009A. Ceccucci 4

5. CERN, 11-5-2009A. Ceccucci 5Proposed Detector LayoutSPS primary p: 400 GeV/c Unsepared beam: 75 GeV/c 800 MHz p/K/p (~6% K+)K+p+nn~11 MHz of K+ decaysK+p+ n nSensitivity is NOT limited by protons fluxNeeds ~same amount of protons on target as NA48 (GTK)

6. CERN, 11-5-2009A. Ceccucci 6Principles of NA62K+ Decay in-flight to avoid the scattering and the backgrounds introduced by the stopping target long decay regionHigh momentum to improve the background rejection  unseparated hadron beam Precise timing to associate the decay to the correct incoming parent particle (K+) in a ~800 MHz beam  Beam tracker with st~100 (GTK) 2. Kinematical Rejection low mass tracking (GTK + STRAW in vacuum tank)3. Vetoes (g and m)  ANTI ( OPAL lead glass) + NA48 LKR  MUV 4. Particle Identification K/p (CEDAR)  p/m (RICH)

7. NA62 Event DisplayCERN, 11-5-2009A. Ceccucci 7GTKANTISTRAWLKRRICHMUVVacuum tank not shown

8. CERN, 11-5-2009A. Ceccucci 8Background RejectionDecayBRK+m+n (Km2)0.64K+ p+p0 (Kp2)0.21K+ p+p+p- K+ p+p0p00.07~92% of Kaon decaysare kinematically constraintSignature:Incoming high momentum (75 GeV/c) K+ Outgoing low momentum (< 35 GeV/c) p+For Kp2 P(p0) > 40 GeV/c: it can hardly be missedK+p+

9. CERN, 11-5-2009A. Ceccucci 9Decay ModeEventsSignal: K+p+nn [ flux = 4.8×1012 decay/year] 55 evt/yearK+p+p0 [hp0 = 2×10-8 (3.5×10-8) ]4.3% (7.5%)K+m+n2.2%K+e+p+p-n3%Other 3 – track decays1.5%K+p+p0g~2%K+m+ng~0.7%K+e+(m+) p0n, othersnegligibleExpected background13.5% (17%) NA62 Sensitivity Definition of “year” and running efficiencies based on NA48 experience:~100 days/year; 60% overall efficiency

10. CERN, 11-5-2009A. Ceccucci 10Key PointsThe physics case to study rare kaon decays at the SPS during the LHC era is very strong The experiment was approved by the CERN Research Board (December 5, 2008) "subject to the definition of resource sharing within the Collaboration” The MoU is under negotiationWith ~50 times the kaon flux of NA48/2, the physics menu –in addition to the very rare decays- promises to be rich ranging from the precision-tests of lepton universality to the study of the strong interaction at low energyExcellent resolution, hermetic forward coverage and strong particle ID allow also to search for (e.g.):Sgoldstinos (Gorbunov&Rubakov): K+→p+p0P, P→ gg, P→e+e- or P long-lived nMSM Neutral Leptons (Gorbunov&Shaposhnikov)

11. Status of NA62CERN, 11-5-2009A. Ceccucci 11

12. CERN, 11-5-2009A. Ceccucci 12GTK StationR-O chipSi sensor pixel matrixmechanical supportRequirements:Track and time each beam particleTime resolution: 200 ps / stationMaterial Budget: < 0.5 % X0 / stationPattern: 300 x 300 mm2Two options for the Read-Out: On-Pixel TDC End-of-Column TDC

13. Gigatracker R/O PrototypesCERN, 11-5-2009A. Ceccucci 13INFN Design: One TDC / pixel CERN Design: End of Column TDC Both Designs in 130 nm IBM CMOSTechnology (submitted in March 09)

14. STRAW TrackerInterface ring flangesSquare ViewsOne Station

15. CERN, 11-5-2009A. Ceccucci 15STRAW PrototypeUltrasound Welded mylar (linear weld, no glue!)36 Al12 (Cu+Au) mylar straws

16. CERN, 11-5-2009A. Ceccucci 16STRAW Prototype: Beam Test RUN 20629, muonsResidualsRMS=104 μm σ = 45 μmcmRMS=100μm σ = 43 μmRUN 20650, pionscmRMS=122 μm σ = 45μmRUN 20694, kaonscmCO2 (80%) CF4 (10%) Isob. (10%)Resolution (cm)2200V2300V2400VThr=6 fC, pionsDrift Distance (cm)full length StrawPrototype: 2.1 m longOperated in Vacuum

17. CERN, 11-5-2009A. Ceccucci 17Photon ANTIcountersCABLINGSUPPORTSMAN HOLEOPAL LEAD GLASSESHANDLINGANTI 1-5

18. Prague, Apr 15, 2009 A. Ceccucci 18Photon ANTIcountersOPAL LEAD GLASS BEING PROCESSEDFOR USE IN NA62 in Building 904 at CERN

19. First ANTI Vessel complete 1st Complete vessel being Prepared at LNF for installationIn the decay tankTo be integrated in the existing decay tankSpace for Installation andMaintenance comes ata premium in ECN3Prototype STRAW and ANTITested in vacuum

20. ANTI-A1 at LNF for AssemblyCERN, 11-5-2009A. Ceccucci 20

21. CERN, 11-5-2009A. Ceccucci 21RICH-100: Test Beam Results Dqc≈ 50 mrad(biased by PM geometry)NHits ≈ 17DtEvent ≈ 70 ps96 PMT Hamamatsu R740017 m focal, 50 cm wide, 2.5 cm thick glass mirror 200 GeV/c h- In two weeks from now:RICH-400 (414 PMT) 20% of final detectorValidate p-m separation in 15<p<35 GeV/c

22. Summary With 2 (+1) years of data taking at the SPS, NA62 can make a ~10% test of the SM BR prediction This requires a SPS duty cycle of about 0.3 and 1.1 x 1012 protons on T10 / effective secondA beam survey should be planned early (2011) to begin data taking with the full detector in 2012The construction schedule is mostly resource driven In the longer term, we look forward to SPS and Experimental Area upgrades as these could open the opportunity to study ultra-rare K0L decays CERN, 11-5-2009A. Ceccucci 22

23. CERN, 11-5-2009A. Ceccucci 23SPARES

24. Prague, Apr 15, 2009 A. Ceccucci 24 KL→p0nn Long Time ProspectsSPSE391aJ-PARCSPS is competitive if the KAMI/E391a technique is establishedPicture adapted from KAMI proposalSPSProject XU-70

25. CERN, 11-5-2009A. Ceccucci 25 New Straw Tracker Old Chambers Hevacuum ~120 mvacuum ~2.5 mK+nnp+K+nnp+The Straw Tracker is essential to study ultra-rare-decays in flightThe Straw Trackers operated in vacuum will enable us to:Remove the multiple scattering due to the Kevlar WindowRemove the acceptance limitations due to the beam-pipeRemove the helium between the chambers New Spectrometer LKrRICHKevlarWindowBeam PipeStraw Trackers

26. CERN, 11-5-2009A. Ceccucci 26LKr g Detection Efficiency (Measured from data) Cluster not reconstructedEg = 22 GeVPion P=42 GeV/cPhoton E=11 GeVExpectedpositionp+ track and lower energy g are use topredict the position of the other g LKr ineff. per g (Eg > 10 GeV): h ~ 7 × 10-6 (preliminary)K+  p+ p0 selected kinematically

27. CERN, 11-5-2009A. Ceccucci 27The RICH DetectorNeon Gas at atmospheric pressure Mirror Mosaic(17 m Focal Length) 2×1000 PMT(hex packing 18 mm side)Vessel: 17 m long, 3 m ddBeam PipeBeam

28. CERN, 11-5-2009A. Ceccucci 28RICH Simulation: particles separationMuon suppression in p sample (15<p<35 GeV/c): 1.3×10-3Momentum fromthe magnetic spectrometer

29. RIIRIm2miss GeV/c2Kinematical Rejection K+p+p0 selected on 2007 data using LKr information onlyLook at the tails in the m2miss reconstructed with the NA48 DCH Data vs. NA48MC: reproducibility of non- gaussian tails within x2K+p+nn regions: background ~210-3 m2miss GeV/c2OLD DCH: Data vs. MC New Straw Tracker: MC CERN, 11-5-200929A. Ceccucci

30. CERN, 11-5-2009A. Ceccucci 30K+→ p+ n n: Physics MotivationNLO QCD [Buchalla, Buras ‘94], [Misiak, Urban ’99], [Buchalla, Buras ’99]CharmNNLO QCD [Buras, Gorbahn, Haisch, Nierste ’06]EW Corrections to Pc [Brod, Gorbahn ’08]Long Distance|DE|< 1% [Mescia, Smith ’07] dPc,u +6% [Isidori, Mescia, Smith ’05]The SM Branching Ratio prediction is precise (~8%) and the intrinsic theory error is smallThe parametric error will be further reduced[J. Brod @ CKM’08]In the Standard Model:l= Cabibbo Angle

31. CERN, 11-5-2009A. Ceccucci 31SM Prediction vs. ExperimentAnd, for comparison:Future: E14 (KOTO) @ J-PARC [E391a ’08]For mc=(1286 ± 13) MeV [Kühn et al. ’07]As reported by J. Brod, CKM ’08[E787, E949 ’08]

32. CERN, 11-5-2009A. Ceccucci 321. Precise Timing Unseparated beam, in-flight decay: How do you associate the parent kaon to the daughter pion in a ~1 GHz beam ?K+ : Gigatracker (pixel detector) with very good time resolution (~ 100 ps) p+ : RICH (Neon, 1 atm) read out by Photomultipliers K+pp+p+p+nnp+Gigatracker (rate ~ 1 GHz)RICH (rate ~ 10 MHz)~120 m CEDAR (rate ~ 50 MHz)

33. CERN, 11-5-2009A. Ceccucci 33NA48NA62Nota Bene:NAYY ≡ YYth ExperimentPerformed at the North Area SPS Extraction siteThe CERN proton Complex is uniqueThe SPS is neededas LHC protoninjector only part-timeFor the reminder of the time it canprovide 400 GeV/cprotons for fast or slow extraction

34. Prague, Apr 15, 2009 A. Ceccucci 34 Timescale 2009201020112012K12 CEDARGTKLAVSTRAWRICHLKRMUVTDAQPMT Procurement: 100 / monthPrototype TestEng 1 Eng 2/Prod Low intensity run (no GTK) High intensity run (GTK) Production of Mechanics & AssemblyTELL1/TTC Proc.

35. CERN, 11-5-2009A. Ceccucci 354. Particle Identification K+ Positive identification (CEDAR) p/m separation (RICH) p/e separation (E/P)DecayBRK+p0e+n (Ke3)0.051K+p0m+n (Km3)0.034K+m+n g (Km2g)6.2×10-3K+ p+p-e+n (Ke4)4.1×10-5K+p+p-m+n ( Km4)1.4×10-5pK+  m+ p0 n