1. September 27, 2005Status Report, SPSC 1 Experiments NA48/1 & NA48/2 Status Report (SPSC-2005-031) CERN, Cambridge, Chicago, Dubna, Edinburgh, Ferrara, Firenze, Mainz, Northwestern, Perugia, Pisa, Saclay, Siegen, Torino, Vienna Collaboration: V.Kekelidze for

2. September 27, 2005Status Report, SPSC 2 Content  Introduction  Rare decays in the experiment NA48/1  Search for direct CP-violation in the NA48/2  Test of  PT: precise measurement of the  -  scattering length  Rare decay of charged kaons  Leptonic & semileptonic decays  Summary & request

3. September 27, 2005Status Report, SPSC 3 High Precision Study of Kaon & Hyperon Decays Physics motivation for the experiments  Search for new physics & tests of the SM  High accuracy tests of low energy QCD (  PT)  Quantitative tests of various model predictions NA48/1NA48/1 2000 Phase I (no spectrometer): K S & K L decays 2002 Phase II (high intensity run): K S & Hyperon decays K S in fiducial volume: ~ 3.5 10 10 NA48/2NA48/2 simultaneous K + and K - beams 2003 – 2004 K  in fiducial volume: > 2. 10 11

4. September 27, 2005Status Report, SPSC 4 Rare decays in the experiment NA48/1

5. September 27, 2005Status Report, SPSC 5 Measurement of Br(K S  e ) Br = ( 6.8  0.2 stat  02 sys )10 -4 PDG value : (6.9  0.4)10 -4 analysis finished paper preparation is in progress is improved in precision ~13’000

6. September 27, 2005Status Report, SPSC 6  0  + e + e decays BR= ( 2.57  0.12 stat +0.10 –0.09 syst )10 -4 in good agreement with our measurement: BR= (  0  + e - e )= ( 2.51  0.03 stat  0.09 syst )10 -4

7. September 27, 2005Status Report, SPSC 7  0  +  -  decays BR= ( 2.2  0.3 stat  0.2 syst )10 -6 102 decays 32  3.0 background most precise measurement paper in preparation KTEV: (4.7 +0.2 -1.4 stat  0.8 sys )10 -6

8. September 27, 2005Status Report, SPSC 8 R= N (  0 )/ N (  0 ) R= ( 9.31  0.05 stat  0.04 syst )10 -2 new (preliminary) Br(K S   +  -  0 ) submitted to PRL

9. September 27, 2005Status Report, SPSC 9 Search for direct CP-violation in NA48/2

10. September 27, 2005Status Report, SPSC 10  Direct CP violation in K ±   ±  ±, K ±   ±  0  0 M ( u )  1 + g  u, u = f ( )  g = g + - g - = 2  A g   (A g ) < 2  10 – 4 (limited by statistics) Goal g + - g - A g = ———— g + + g - Requirements to experiment: high statistics (~ few  10 9 decays) stability in time set –up symmetry

11. September 27, 2005Status Report, SPSC 11 Measurements & predictions 10 -6 |A g | Experimental precisions by 2005: 10 -5 10 -4 10 -3 10 -2 SM SUSY Newphysics Ford et al. (1970) HyperCP prelim. (2000) TNF prelim. (2002) “neutral” mode NA48/2 proposal few 10 -6 …8x10 -5 SM estimates vary within an order of magnitude (few 10 -6 …8x10 -5 ). Models beyond SM predict substantial enhancement partially within the reach of NA48/2. [  A g ~10 -3 ] “charged” “neutral” Theory Asymmetry in decay widths expected to be smaller than in Dalitz-plot slopes (SM: ~10 -7 …10 -6 ).

12. September 27, 2005Status Report, SPSC 12 NA48/2 method –Two simultaneous K + and K – beams, superimposed in space, with narrow momentum spectra; –Detect asymmetry exclusively considering slopes of ratios of normalized U distributions; –Equalize K + and K – acceptances by frequently alternating polarities of relevant magnets.

13. September 27, 2005Status Report, SPSC 13 1cm 50100 10 cm 200250 m vacuum tank He tank + spectrometer magnet B+ K+K+ K-K- K+K+ K-K- NA48/2 experiment configuration 114m decay volume focusing beams DFDF Quadrupole Quadruplet beams coincide within <1mm FDFD FRONT-END ACHROMAT P K spectra, 60  3 GeV/c 54 60 66 The simultaneous K + and K - beamsNA48 Set-Up not to scale TAX 17 TAX 18 ~7  10 11 ppp 2 nd ACHROMAT BM z

14. September 27, 2005Status Report, SPSC 14 2003 run: ~ 50 days (~ 1 month stable conditions) 2004 run: ~ 60 days ~ 200 TB of data recorded NA48/2 runs

15. September 27, 2005Status Report, SPSC 15 recorded events, 10 6 # of Super-Samples Run K    -  +   K    0  0   (complete cycles) 2003-I67020SS0 2003-II94028SS1-3 Statistics data taken in 2004: calibrated, reprocessed & filtered analysis started

16. September 27, 2005Status Report, SPSC 16 Super-samples 2003 DatesSub- samples Achromat A+Achromat A– K+K+ K–K– K+K+ K–K– 022.06-25.0726229.6125.9201.0114.0 16.08-20.0812122.568.1135.175.4 220.08-3.0912147.281.8105.558.9 33.09-7.09440.622.654.530.4 Total54Total events selected1613.2 Statistics selected for A g measurement, events x10 6

17. September 27, 2005Status Report, SPSC 17 Selected statistics 2003 U |V| even pion in beam pipe Data-taking 2003: 1.61x10 9 1.61x10 9 events selected K + : 1.03x10 9 events K  : 0.58x10 9 events  odd pion in beam pipe  M =1.7 MeV/c 2 Events

18. September 27, 2005Status Report, SPSC 18 Beam movement in time X, cm Y, cm DCH1 (upstream magnet) K+ KK X, cm Typical scales: beam movement in time ~2mm beam width ~5mm Y, cm 0 0.4 0.8-0.4 -0.8 0 0.4 0.8 -0.4 -0.8 X, cm Beam profile @DCH1 (a small fraction of data)

19. September 27, 2005Status Report, SPSC 19 cancellation Acceptance cancellation within a supersample N(A+B+K+) N(A+B-K-) R US = Detector left-right asymmetry cancels in 4 ratios of K + over K  u -spectra: Z X Y Jura Saleve Achromats: K + Up Achromats: K + Down B+ BB Indexes of R’s correspond to beamline polarity (U/D); direction of kaon deviation in spectrometer magnet field (S/J) same deviation direction by spectrometer magnet in numerator and denominator; same deviation direction by spectrometer magnet in numerator and denominator; data from 2 different time periods used at this stage. data from 2 different time periods used at this stage. N(A+B-K+) N(A+B+K-) RUJ=RUJ= N(A-B+K+) N(A-B-K-) RDS=RDS= N(A-B-K+) N(A-B+K-) R DJ = R(u) = R US  R UJ  R DS  R DJ =N  (1+4  g  u)

20. September 27, 2005Status Report, SPSC 20 Example of fits: supersample 1 U U U U U  2 =38.1/38  2 =37.5/38  2 =50.5/38  2 =35.6/38  2 =34.8/38 A=(2.4±4.6)x10 -4 A US =(2.4±4.6)x10 -4 A=(8.2±4.4)x10 -4 A DS =(8.2±4.4)x10 -4 A J =(-0.2±4.6)x10 -4 A UJ =(-0.2±4.6)x10 -4 A=(-1.0±4.4)x10 -4 A DJ =(-1.0±4.4)x10 -4  =(2.3±2.2)x10 -4 R (u)/N

21. September 27, 2005Status Report, SPSC 21 Time-stability (vs super-sample) 0 5 10 15 20 -5 -10 -15 -20 x10 -4 Monte-Carlo describes effects of permanent magnetic fields and differences of beamline properties (  S -  J )/2 (  D -  U )/2 left / rightup / down set-up asymmetry:

22. September 27, 2005Status Report, SPSC 22 Stability vs kinematic variables 0 10 20 30 40 -10 -20 -30 -40  g x10 -4 0 20 40 60 80 -20 -40 -60 -80  g x10 -4

23. September 27, 2005Status Report, SPSC 23 Result & systematics Conservative estimations of systematic errors Effect on Δx10 4 Acceptance and beam geometry 0.5 Spectrometer alignment0.1 Analyzing magnet field0.1 π ±  decay 0.4 U calculation and fitting0.5 Pile-up0.3 Syst. errors of statistical nature Trigger efficiency: L20.8 Trigger efficiency: L10.4 Total Total systematic error1.3 RawCorrected for L2 eff SS00.0±1.50.5 ± 2.4 SS10.9±2.02.2 ± 2.2 SS2-2.8 ± 2.2-3.0 ± 2.5 SS32.0 ± 3.4-2.6 ± 3.9 Total-0.2 ± 1.0-0.2 ± 1.3 2222 2.2 / 33.2 / 3 Combined result: Δx10 4 (3 independent analyses) L2 trigger systematics included

24. September 27, 2005Status Report, SPSC 24 Preliminary result: 2003 data Slope difference: Δg = (-0.2±1.0 stat. ±0.9 stat.(trig.) ±0.9 syst. )  10 -4 = (-0.2±1.7)  10 -4 Charge asymmetry: A g = (0.5±2.4 stat. ±2.1 stat.(trig.) ±2.1 syst. )  10 -4 = (0.5±3.8)  10 -4 systematic errors are conservative for preliminary result better control of systematics in 2004 due to: - more frequent polarity alternation - better L2 performance

25. September 27, 2005Status Report, SPSC 25 specific features:  one charged track (  ± ) to measure asymmetry  Lkr used for  0  0 identification  different acceptance (u) & large g 0 = 0.652 ± 0.033 Asymmetry in K ±   ±  0  0 preliminary result based on SS0-SS3 (~ 48 M decays)

26. September 27, 2005Status Report, SPSC 26 K      0  0    + 4  mm reconstruction algorithm  pairs of  ’s should have a common vertex compatible with kaon decay E 1 E 2  (d 12 ) 2 LKr

27. September 27, 2005Status Report, SPSC 27 Reconstructed decays K ±   ±  0  0 K+K+ preliminary result based on SS0-SS3 (~ 48 M decays) K-K- ~31M~17M

28. September 27, 2005Status Report, SPSC 28 Data analyzed: SS-0,-12,-3  g 0 = (2.2  2.2 stat)10 -4 u u u R(u), 10 -4 SS0 SS12 SS3 R(u), 10 -4

29. September 27, 2005Status Report, SPSC 29 Stability check & comparison with MC left / rightup / down set-up asymmetry: MC exper. 10 -4 g0g0 A S -A J A U -A D

30. September 27, 2005Status Report, SPSC 30 Stability checks of obtained  g 0 PKPK VzVz day sample |V| 10 -4 g0g0 g0g0

31. September 27, 2005Status Report, SPSC 31 Result (preliminary): three analyses obtain very close results A 0 g major systematics in 10 -4 units : alignment (< 0.1) acceptance & beam geometry (< 0.1) momentum scale (< 0.1) u-calculation & fit (< 0.4) accidentals (< 1.0) L1 trigger (< 1.5), L2 trigger (< 0.4), fit region (0.0025), LKr nonlinearity corrections (< 0.4) A 0 g = (1.7  1.7 stat  1.2 trig  1.0 syst  0.2 extern )  10 -4

32. September 27, 2005Status Report, SPSC 32 Test of  PT : precise measurement of the  -  scattering length

33. September 27, 2005Status Report, SPSC 33  Theory calculation  predicted by  PT first principles (Weinberg 1966)  G.Colangelo, J.Gasser, H.Leutwyler, NP B603(2001)125  scattering length m  + = - 0.0444 ± 0.0010m  + = 0.220 ± 0.005 ( - ) m  + = - 0.265±0.004  1.5%  Experimental measurements  mesoatom lifetime (DIRAC)   form-factors in K e4 decays for the first time : Geneva-Saclay (1977): 30,000 events best measurement: BNL E865 (2001): 400,000 events precision limited by statistics | - | 2 = 0.216 ± 0.013 stat ±0.002 syst ±0.002 theor m   ~ 6 %  Statistics of NA48/2: > 1,000,000 K e4 events

34. September 27, 2005Status Report, SPSC 34 measurement of from K   (3  )   simple model : N. Cabibbo, P.L.B 93(2004)121801 A threshold effect in M(  0  0 ) has been observed (cusp structure) for the first time in NA48/2 thanks to  high resolution in energy  high statistics collected indication to the re-scattering of  +  -   0  0 in the decay K    +  -     0  0   is related to ( - ) New way !  two loops approximation: N.Cabibbo, G.Isidori, JHEP03(2005)021 (I symmetry is foreseen)  introduce I-breaking parameter  = (m + 2 - m o 2 )/m + 2 = 0.065 M.Knecht, R.Urech, N.P. B519(1998)329; G. Colangelo,J.Gasser,B.Kubis,A.Rusetsky: Kaon Mini-workshop (CERN-05)

35. September 27, 2005Status Report, SPSC 35 First Observation of the  +  - -threshold in K   M  0  0   decays M 2 (  0  0 ), (GeV/c 2 ) 2 4m 2 (   )= 0.0779(GeV/c 2 ) 2 ~23M decays

36. September 27, 2005Status Report, SPSC 36 Fit quality  Simple Cabibbo model: a x m + = ( a 0 - a 2 )m + /3  2 /D.F. = 420.1 / 148  = data - MC  Cabibbo, Isidori: two loop approximation; I- breaking (1 parameter) ( a 0 - a 2 )m +, a 2 m +, g 0, h +, N  2 /D.F = 154.8 / 146  …..+ pionium (1.61  0.66)10 -5  2 /D.F.=149.1 / 145 consistent with Z.Silagadze calc: 0.8  10 -5  exclude pionium region  2 /D.F.=145.5 / 139

37. September 27, 2005Status Report, SPSC 37 Results (paper in preparation): two analysis (different MC & criteria) obtain very close results m + major systematics : acceptance (0.001) trigger (0.001) fit region (0.0025) LKr resolution & nonlinearity (0.001) track-  separation (0.002) taking into account uncertainty in theory ~ 5% (ext): ( - ) m + = 0.268  0.010 stat  0.004 syst  0.013 ext m + = - 0.041  0.021 stat  0.014 syst ( - )

38. September 27, 2005Status Report, SPSC 38 m + = 0.220  0.006 stat  0.004 syst  0.003 R  0.011 theor m + = 0.264  0.006 stat  0.004 syst  0.003 R  0.013 theor Results ( continuation ): taking into account uncertainty in R= A ++- / A +00 & theoretical constrains between experimental uncertainty < 3% - limited by statistics which will be increased using 2004 data by factor ~ 4 ( - ) &

39. September 27, 2005Status Report, SPSC 39 K ±   +  - e ± ν (K e4 ) taking into account additional data (SS0 & 2004) it is expected in total : > 1000k decays background selection: 2003 data SS1-3: ~ 350k (background ~0.5%) m products expected precision in better than ±0.010 stat

40. September 27, 2005Status Report, SPSC 40 Cabibbo-Maksymowicz variables background ,  e have opposite sign for K + & K - ( T.D. Lee and C.S.Wu –1966 ) d 5  K- (m ,m e,  ,  e,  )= d 5  K+ (m ,m e,  ,  -  e,  +  )  -  line of flight in K rest frame both K + and K - decays are accumulated at similar experimental conditions this allows to tests CP, and CPT (for the fist time) and provide reliable cross checks for possible systematic ancertainties

41. September 27, 2005Status Report, SPSC 41 Other Rare Decays of Charged Kaons SS1-3: ~1 month of running in 2003

42. September 27, 2005Status Report, SPSC 42 Goals  Rare decays to test  PT & search for A CP K      , K      0  DE K     e + e , K      +  , K  e2 K   l  l + l  K      0 , K      0 l + l , … etc.

43. September 27, 2005Status Report, SPSC 43 K      0  PDG T  : 55 – 90 MeV Br=(2.75  0.15)10 -4 DE contribution: Br=(4.7  0.9)10 -6 Interference term – possible source of CPV (order of magnitude higher than others)

44. September 27, 2005Status Report, SPSC 44 Z=(M(ee)/M K ) 2 M(  ± e + e - ), GeV/c 2 Statistics comparable to the World best sample at low background (1-2%) K ±   ± e + e - & K ±   ±  +  - K ±   ± e + e -. Statistics > PDG Analyses are ongoing: form-factors study

45. September 27, 2005Status Report, SPSC 45 Leptonics & Semileptonics of Charged Kaons Special minimum-bias runs in 2003 & 2004

46. September 27, 2005Status Report, SPSC 46 Goals  Leptonics & Semileptonic decays: K  e3, K   3 BR’s  to improve precision of |V us | & check CKM unitarity, check  -e universality form-factors  to search for f T, f S

47. September 27, 2005Status Report, SPSC 47 Results (preliminary) R(Ke3/K2  ) = 0.2505  0.0009 stat  0.0012 syst R(K  3/K2  ) = 0.1646  0.0006 stat  0.0011 syst R(K  3/Ke3) = 0.657  0.003 stat  0.003 syst R(Ke2/K  2 )= 2.416  0.043 stat  0.024 syst 2003 run R(Ke2/K  2 )= 2.453  0.046 stat  0.026 syst 2004 run PDG = 2.45  0.11 SM = 2.472  0.001

48. September 27, 2005Status Report, SPSC 48 Summary & Request Special minimum-bias runs in 2003 & 2004

49. September 27, 2005Status Report, SPSC 49  NA48/1 high precision results are obtained on Ks decays and hyperon semileptonics, (analysis continues)  NA48/2 first results are obtained on charged asymmetry in both K ±   ±  +  - and K ±   ±  0  0 decays based on 2003 data achieved precision is limited by statistics

50. September 27, 2005Status Report, SPSC 50 NA48/2 NA48/2 (cont.)  A “cusp” structure has been observed for the first time in K    0  0   decays which allows to high precision measurement of  -  scattering length  Large sample of both signs of K ± e4 decays provides good opportunity for high precision measurements of  -  scattering length & for the first time - various asymmetries

51. September 27, 2005Status Report, SPSC 51  Large statistics of K ± decays is accumulated for the study of various rare decays  Precise measurement of K ± leptonics & semileptonics decays contributes to the CKM unitarity &  -e universality checks NA48/2 NA48/2 (cont.)

52. September 27, 2005Status Report, SPSC 52  2003 data -analysis ongoing  2004 data -calibrated, reprocessed & filtered -analysis has started NA48/2 NA48/2 (cont.)

53. September 27, 2005Status Report, SPSC 53 Resources Request for 2006 Data storage at CERN: reserve CASTOR space ~ 5 TB for MC data ~ 30 TB for possible reprocessing (?), CPU power: guaranteed share for ongoing analysis

54. September 27, 2005Status Report, SPSC 54 Spares

55. September 27, 2005Status Report, SPSC 55 Results on A g Other experiment data on A g c  BNL (1970): (- 7.0 ± 5.3)∙10 -3  FNAL, HyperCP –2000 (preliminary) (2.2±1.5±3.7)∙10 -3  Serpukhov data on A g 0  I.V.Ajinenko et al., PLB567(2003)159.: (5.1 ± 2.8 )∙10 -3  G.A.Akopdzhanov, hep-ex/0406008 prelim.: (0.2 ± 1.9 )∙10 -3

56. September 27, 2005Status Report, SPSC 56 Leptonic decay selection 56 hour minimum-bias run in 2004 K   e  K     3.9  10 6 4000 (missing mass) 2,(GeV/c 2 ) 2

57. September 27, 2005Status Report, SPSC 57

58. September 27, 2005Status Report, SPSC 58 Basic K e4 + and K e4 - form factors