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STATUS OF KLOE

STATUS OF KLOE. F. Bossi,. KLOE-LNF. CSN1. Frascati, May 13 2002. KLOE SUBMITTED PAPERS. Accepted Reference.

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STATUS OF KLOE

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  1. STATUS OF KLOE F. Bossi, KLOE-LNF CSN1 Frascati, May 13 2002

  2. KLOE SUBMITTED PAPERS Accepted Reference Measurement of the b.r for the April 10 PLB 535, 37 decay Ks pen hep-ph0203232 Measurement of May 9 hep-ex0204024 G(Ks p+p-(g)) / G(Ks p0p0) Study of the decay f  p0p0g with April 24 hep-ex0204013 the KLOE detector Study of the decay fp0g with April 24 hep-ex0204012 the KLOE detector Based on year 2000 data : 17 pb-1 analyzed / 23 collected

  3. KSSEMILEPTONIC DECAYS 1. KS p+ p- Paper dedicated to the memory of L. Paoluzi • Motivation: •  If (CPT ok) .AND. (DS=DQ at work): • G(KS p en) = G(KL p en) BR(KS p en) = BR(KL p en) x (GL/GS) • = ( 6.704 ± 0.071 ) x 10-4 • (using all PDG information). • Only one measurement 75events (CMD-2 1999): • = ( 7.2 ± 1.4 ) x 10-4 • Selection procedure •  Vertex with two tracks from I.P. •  kinematics (against huge p+p- “background”) •  time of flight ( electron vs pion) •  final signal variable = Emiss-|pmiss| 2. KS p en ToF selection illustrated for MC events

  4. 2000 BR(KS p en) = (6.91 ± 0.34stat ± 0.15syst) x 10-4

  5. G(KSp+p-) / G(KSp0p0) Motivations:  First part of double ratio  Extractions of Isospin Amplitudes and Phases A0 A2and d0-d2 consistent treatment of soft g in KS p+p- (g) (PDG data contain ambiguities) [Cirigliano, Donoghue, Golowich 2000] Selection procedure: 1. KS tagging 2. KS p+p-(g) two tracks from I.P + acceptance cuts: fully inclusive measurement eppg(Eg*) from MC  folded to theoretical g spectrum 3.KS p0p0 neutral prompt cluster (Eg>20 MeV and (T-R/c) < 5st ) at least 3 neutral prompt clusters (p0 e+e-g included)

  6. G(KSp+p-) / G(KSp0p0) KLOE 2000 data 2.236 0.003stat 0.015syst fully inclusive PDG 2000 2.197  0.026 ( without clear indication of Eg*cut )

  7. f Scalar Meson + g[f0(980) I=0, a0(980) I=1] Motivations: f0, a0, not easily interpreted as qq states; other interpretations suggested:  qqqq states (lower mass) [Jaffe 1977];  KK molecule (m(f0,a0)~2m(K)) [Weinstein, Isgur 1990];  f0(980) , a0(980) and s  lowest mass scalar qq nonet [Tornqvist 1999] f  f0g , a0g  sensitive to f0,a0 nature [Achasov, Ivanchenko 1989]: phenomenological framework (kaon loop model)  coupling constants radiative g g(fKK) from G(fK+K-) g(f0KK) g(a0KK) f0, a0 model g(f0pp) g(a0hp) M(p0p0) M(hp) spectra f0,a0 f Kaon loop final state

  8. f0 momentum depends on structure

  9. f  p0p0g • Main background sources (5g final states): • e+ewp0 w  p0g • f  hp0g h  gg • Other background sources (not 5g final states): • f  hg h  gg (3g) or h  p0p0p0 (7g) • Selection procedure: •  5 prompt g Eg > 7 MeV •  kinematic fit (without mass const.) • Result: • Nev = 2438  61 •  BR(f  p0p0g )=(1.09  0.03stat  0.05syst)x10-4 • CMD-2 (0.920.080.06)x10-4 • SND (1.140.100.12)x10-4 • Fit to the Mp0p0 spectrum (kaon loop): • contributions from f  f0g • f  sg • + “strong” negative interference • negligible contribution f  r0p0 p0p0g Fit results: M(f0) = 973  1 MeV g2(f0KK)/4p = 2.79  0.12 GeV2 g(f0pp) /g(f0KK) = 0.50  0.01 g(fsg) = 0.060  0.008 BR(f  f0g  p0p0g ) = (1.49  0.07)x10-4

  10. f  hp0g Measured in 2 final states: (Sample 1) h  gg (5g)  p0p0g is the main background  5g selection (see p0p0g) + kinem. fit (Sample 2) h  p+p-p0 (2t + 5g)  Negligible bckg with the same topology: e+ewp0 w  p+p-p0 2t + 4g f  KSKL (KL prompt decay) 2t + 4/6g  2t + 5g selection + kinem.fit Results: (Sample1) Nev = 916 Nbck = 309  20  BR(f  hp0g) = (8.5  0.5stat 0.6syst)x10-5 (Sample2) Nev = 197 Nbck = 4  4  BR(f  hp0g) = (8.0  0.6stat 0.5syst)x10-5 CMD-2 (9.02.41.0) x 10-5 SND (8.81.40.9) x 10-5 Combined fit to the Mhp0 spectra: dominated by f a0g negligible f  r0p0 hp0g Fit results: M(a0) = 984.8 MeV (PDG) g2(a0KK)/4p = 0.40  0.04 GeV2 g(a0hp) /g(a0KK) = 1.35  0.09 BR(f  a0g  hp0g) = (7.4  0.7)x10-5

  11. (flavor basis) (octet-singlet basis) A PAPER TO COME: Fg F KLOE 2000 data BR(f  hg) Preliminary hep-ex 0107022, KLOE coll. Measurement of BR(f  h’g)/BR(f  hg) gives most accurate determination of pseudoscalar mixing angle to date: • BR(f h’g)/BR(f  hg) = • (5.3  0.5stat 0.3syst) ·10-3 • using PDG value for BR(f  hg) we obtain: • BR(f  h’g) = (6.8 0.6stat  0.5syst) ·10-5 (flavor basis) (octet-singlet basis) gluonium content for the’ < 10%

  12. KLOE 2001 DATA TAKING CAMPAIGN Successful in terms of Ldt About 175 pb-1 collected 110 days of run Best day: 3 pb-1 / 24 h LPEAK= 5 1031 cm-2 s-1 LAVG = 3.5 1031 cm-2 s-1 Painful in terms of backgrounds Online bckg counter rates > by factor 2-5 wrt 2000 data How much of this can we really use ?

  13. 2001 DATA ANALYSIS Repeat previous Determine KL BRs : Under way (see next) e.g. KLgg Charged kaon decays  Measurement of sHAD to 1% KSgg Feasibility study KS3p

  14. IMPROVE 2000 ANALYSIS KSp+p– / KSp0p0 : As a part of double ratio, goal in accuracy is 1‰ ( 7‰ now) Most of efficiencies determined by data (KLp+p–p0 ,  …) system. scale ~ statistics KS p en : Together with KL  p en tests DS = DQ and CPT Also we can start looking at leptonic asymmetry This can last forever…

  15. KLgg Motivation : Useful in computations of rare KLdecays (KL m+m– …) Goal: improve present accuracy of 2.5% ( PDG: dominated by NA31 G(KLgg)/ G(KL3p0) ) Strategy : determine BR from G(KLgg)/ G(KL3p0) known to 1.3% acc. (PDG)

  16. KLgg Signature : Neutral vertex with 2 (gg) or > 4 (3p0) g‘s attached in KSp+p– tagged events Status : Analyzed ~ 100 pb-1 Selected 5648 ± 85KLgg events (good agreement with MC efficiencies) No big problems from machine background due to highly kinematically constrained events Final result expected by summer 2002

  17. KLgg Preliminary Preliminary tKL(ns) Mgg(MeV/c) 30 cm 150 cm

  18. CHARGED KAON DECAYS Together with KLdecays determine sinC to a fraction of 1% Can verify validity of hadronic corrections Many channels remain poorly known Also remeasure all BRs for f  all channels Measure s(e+e- f) ( BR(f  K+K–) ~ 50% ) KLOE profits of the unique feature of tagging By looking at K+  6 x 105 tags/pb-1 or K+ Preliminary results expected by summer 2002

  19. Machine background Tag Tagging Pp Mgg

  20. 2001 DATA REPROCESSING CAMPAIGN Reasons for reprocessing:  Revised physics filter algorithms (charged kaons, neutral kaons, luminosity) Bugs fixes Updated calorimeter calibration Production of compressed format DST’s for physics analysis ( factor ~ 6 data reduction) 18.1 GTriggers 52825 Files 49 TB Raw Data First time we try a massive reprocessing !

  21. 2001 DATA REPROCESSING STATUS Started end January, completed beginning of May Almost all DST produced, but charged kaon stream Day by day Y2001 Data Reprocessing Processed luminosity 3.5 (pb-1/day) Processed triggers ( kHz) 2.5 1.5 Feb. 15 May 7

  22. 2001 DATA SET Y2001 Data set - CPU power cost and data volumes stored for different data taking conditions The entire data amounts to about105 Tbytes, i.e.2650filled cassettes,corresponding to54%of the Tape Library storage space.

  23. 2002 RUN SCHEDULE February : Machine startup March 11 – April 28 : DEAR run Very encouraging results ! April 29 : Start of KLOE run …

  24. From last SC recommendations: …to be revised on April 23/24

  25. Expectations for the Kloe Run Following DEAR experience: Improvements can be obtained both in L and backgrounds: • from sextupoles optimization • from octupoles insertion • from lattice changes • from better orbits • from new scrapers Hopefully improvement of Lt by a factor of ~ 4 within ~ 5 weeks From DAFNE team

  26. START OF YEAR 2002 KLOE RUN Smooth run start: Detector 100% working (including DC ADCs) DAFNE delivering ~ 1.5 pb-1/d Backgrounds lowered by factor ~ 2 Present acquisition rate : 1.5 kHz

  27. Computing & Data Storage 2002 0.04 nb-1 s-1 300 F & Bhabha s -1 1200 Bck s-1 1.5 KHz Trigger Rate 2.6 Kbytes/trigger 4 Mbytes s-1 Raw Data krunc Run Control & DFC Online farm fibm05 .... fibm10 Reconstruction output 560 GB Job control areas 200 GB Recalled Data from Tape 2200 GB 2 IBM B80 I/O Servers • Offline farm • 22 IBM H80 88 CPU • 2.7 KHz : total farm power • SunOS 40 CPU • MonteCarlo • DSTs • 2 IBM + 2 Sun Users fibm01 DB2 Server Magstar 5,500 Cassettes 12 Tape Units 2 IBM B80 AFS Servers 1 TByte

  28. 2002 DATA TAKING CONDITIONS From the first 8 pb-1 Total capacity of the Library inclusive of the Y2001 data set, assuming present running conditions, is400 pb-1corresponding to100 full days of data taking, and if we scratch the filtered sample, is570 pb-1corresponding to177full days of data taking. End of 2002 : new Magstar tape drives available Old cassettes written at higher density 50% increase in the Library capacity.

  29. STORAGE FOR DST’s DST’s are produced immediately after data reconstruction to take advantage of the availability of files on disk To allow an efficient multi user access to these files they should be kept on disk as much as possible Present DST volume: 6 GB/pb-1, excluding charged kaons Estimated DST volume: 25 GB/pb-1, charged kaons included 13 Tbytes by the end of 2002 data taking ~ 3 Tbytes additional disk volume needed (1.6 presently in use)

  30. CONCLUDING REMARKS ON KLOE COMPUTING Disk space : Multi-user access to DSTs (13 Tbytes expected by the end of the year ) requires additional3 TBytes of disk space Library : Full by the end of the year. As soon as they will be available on the market, and according to the data taking status we expect to update the tape drivers to increase the total capacity by 50% New storage solutions are under study for the year 2003 data taking. Computing Power : Less than 50% of the approved total computing power acquired so far. Marginal for any reprocessing campaign, as the 4-full-months needed to reconstruct 180 pb-1 demonstrated. Any new reprocessing campaign will require more .

  31. LONG TERM PLANS AND PERSPECTIVES December 2002 : Start long shutdown ~ 6 months New interaction region : quad triplet  doublet (helped a lot in DEAR ) Goal peak luminosity : 5 x 1032 Here comes CP !!

  32. CONCLUSIONS KLOE has started producing physics results and papers All of the milestones for 2002 have been (up to now) achieved We are analyzing year 2001 data for the next round of papers DAFNE performances this year look promising for more and better data…

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