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Study of  +  - g and 

KLOE General Meeting 13-14 Novembre 2003. Study of  +  - g and . F. Amrosino T. Capussela C. Di Donato F. Perfetto I. Villella. Summary. BR and Asymmetry measurement MC generator.  +  - g  +  -  0   0  0  0. Bin dependence for data and MC

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Study of  +  - g and 

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  1. KLOE General Meeting 13-14 Novembre 2003 Study of+-gand F. Amrosino T. Capussela C. Di Donato F. Perfetto I. Villella

  2. Summary • BR and Asymmetry measurement • MC generator • +- g • +- 0 •  000 • Bin dependence for data and MC • Evaluation of background • Comparisons DATA MC • Refinement of MC procedure • Comparisons DATA MC KLOE General Meeting

  3. eRADstream Mh Eg(Mev) Mppg (MeV) Analysis +- g • Rad stream  e(Egh) • Topological cut • Kinematic fit  P(c2) > 0.01 eAnalysis =46% Lint(2001) =95.7pb-1 KLOE General Meeting

  4. cosqpp Mrecoil (MeV) cosqpp Mppg (MeV) Background rejection fp+ p- p0  Mp0 Mrecoil > 160 MeV e+e- e+e-g(g) e+e-p+ p- g (g)  q Cosqpp> -0.90 e+e-m+ m- g (g) • e=32.6% KLOE General Meeting

  5. Mh Mppg (MeV) Mppg (MeV) h invariant mass KLOE General Meeting

  6. Mppg (MeV) Mppg (MeV) Background subtraction • We exclude signal region and fit background shape from tail: f=a+bx+cx2+dx3 • Background contamination in 520-575 MeV 4% Ntot = 52103 Nbg = 2 103 KLOE General Meeting Ntot = 52374 Nbg = 2259 Sq(Ntot) = 238

  7. Branching Ratio e(ppg)=32.35% e(ppp)=37.9% Nev(ppg)=50115 Nev(ppp)=287627 Preliminary KLOE General Meeting

  8. Preliminary results vs PDG Stat: 1/5 of L Syst: 1% D(N/e)/(N/e); 1% BR(h p+ p- p0); • we have to evaluate contibution from background • subtraction and check emc KLOE General Meeting

  9. Charge Asymmetry KLOE General Meeting

  10. Theoretical Model • Gormley et al. Phys. Rev. D2 (1970) 501 • Angular distribution expected • QCD Anomaly: h/hgg; h/h p+p-g KLOE General Meeting

  11. Test with a toy MC Gormley et al. • GEANFI • Toy MC cosqpg cosqpg KLOE General Meeting

  12. Test with a toy MC Gormley et al. • GEANFI • Toy MC Egh (GeV) Egh (GeV) KLOE General Meeting

  13. Egh (MeV) Egh (MeV) Search for box anomaly • We need gh energy spectrum • efficiency • function • we need much • more statistic • MC simulation Egh (MeV) Background 4% KLOE General Meeting

  14. Summary • New MC generator • BR and Asymmetry measurement • +- g • +- 0 •  000 • Bin dependence for data and MC • Evaluation of background • Comparisons DATA MC • Refinement of MC procedure • Comparisons DATA MC KLOE General Meeting

  15. +-0 |A(x,y)|2 = 1 + aY + bY2 + cX + dX2 + eXY ndf = Nbin - Np KLOE General Meeting

  16. +-0 KLKS +-0 All distributions agree on a background level of B/S  0.6 % KLOE General Meeting

  17. Preliminary fit results • Bin by bin efficiency: OK within analyzed MC statistics accuracy • Background: negligible (almost) • Binning choice (within window): see table below Fit results for different parameterizations of|A(X,Y)|2 KLOE General Meeting

  18. 000 Dalitz Plot parameter definition: |A|2  1 + 2z z [ 0 , 1 ] zrec – ztrue vs. Ztrue: KLOE General Meeting

  19. 000 Cerco bin migliore Dependence of fit vs range fitted in z for various  in input KLOE General Meeting

  20. Very preliminary result on data About 40 pb-1 analyzed, corresponding to roughly same as MC statistics analyzed, with N = 88407 events into the Dalitz plot. First result reads:  = 0.004  0.014 Recall current  measurements: KLOE General Meeting

  21. Fitted shape KLOE General Meeting

  22. Conclusions and Outlooks • Study of high statistics MC sample to make significant DATA – MC comparison on bin by bin basis and assess systematics • Resolution and efficiency study to test theoretical model • More background systematics study for charged channel • Use p0 mass constraint for neutral channel to cross check results • Analyze whole KLOE data sample KLOE General Meeting

  23. DST Production for systematic checks on FILFO and EVCL 2001&2002 data: datarec V13 and V14 Sub-sample from raw-data, without filfo-evcl to study systematic KLOE General Meeting

  24. FILFO-EVCL A minimum bias strategy to select data without filfo selection and without EVCL • At least 3 prompt neutral clusters • qg >18º • SEclu > 500 MeV (all clusters) SEclu > 500 MeV means 3.1 Gb/pb-1 Lint = 50 pb-1 150 Gb KLOE General Meeting

  25. 2001/2002 DST production: • runs: 27000-27137 • Lint=11pb-1 (2002) • Less then 30 G Goal: Lint=50pb-1 over 2001 and 2002 acc/pb-1 RUN KLOE General Meeting

  26. Outlooks • DST production  systematics from filfo-evcl About fhg p+p-7g • minimum bias dst to complete the study of systematic errors • again mc study on official mc mrc.dst to test mc efficiency for signal and background KLOE General Meeting

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