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Update of ppg at large angle (LNF 20/02/2004) See: C.Bini, S.Ventura KLOE Memo 284

Update of ppg at large angle (LNF 20/02/2004) See: C.Bini, S.Ventura KLOE Memo 284 C.Bini, B.Di Micco KLOE Memo 285 (1) Results of the fit (2) Forward-Backward asymmetry (3) Upper limit on h  p + p -. (1) Results of the fit. N(Q) = K  [

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Update of ppg at large angle (LNF 20/02/2004) See: C.Bini, S.Ventura KLOE Memo 284

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  1. Update of ppg at large angle (LNF 20/02/2004) See: C.Bini, S.Ventura KLOE Memo 284 C.Bini, B.Di Micco KLOE Memo 285 (1) Results of the fit (2) Forward-Backward asymmetry (3) Upper limit on h p+p-

  2. (1) Results of the fit N(Q) = K  [ FISR(Q, Mr, Gr, a, b) + FFSR(Q) + Ff0(Q, gfKK, R, mf0)  FINT(Q) + gFrp(Q) + dF3p(Q) ] K = fcoll(Q)  e(Q)  L  b fcoll(Q) = correction for collinear radiation (EVA) e(Q) = efficiency L = integrated luminosity (349 pb-1) b = bin size (1.2 MeV) Results stability checked vs.: Bin size (1.2, 2.4, 6.0, 12.0 MeV) First point (280 to 660 MeV) Last point (996 to 1015 MeV)

  3. 3p background (surviving • the cuts): •  p+p-p0 - MC based abs. normalisation  d • rp background: •  rp , r  pg - Achasov param. - PDG abs. normalisation  g - No interference (??)

  4. - interference no interference + interference

  5. Table with fit results: compare the 3 hypotheses; for fit0 hyp. stability estimate (second error)

  6. Attempt to fit “forcing” f0 p0p0 KLOE parameters: Fit0 c2 = 3700 Fit- c2 = 1313

  7. f0 p+p- after subtraction (red) vs. f0  p0p0 “raw” spectrum (blue) 2 possible explanations: (1) p0p0g spectrum has “another contribution” (2) p+p-g has “another interference scheme”

  8. (2) Forward-backward asymmetry p+p- system: odd terms (green) and even terms (brown) A(ISR) C-odd A(FSR)  C-even A(f0)  C-even |A(tot)|2 = |A(ISR)|2 + |A(FSR)|2 + |A(f0)|2 + 2Re[A(ISR) A(FSR)] + 2Re[A(ISR) A(f0)] + 2Re[A(FSR) A(f0)]  Asymmetry in p+p-q angle (depending on the cuts)

  9. The integrated FB-asymmetry is (two definitions):

  10. Comparison with MC: Eva + Geanfi reconstruction: (red) data (triangles) MC gener. (open circles) MC recon. • data-MC discrepancy below 700 MeV • Clear f0 effect • Data > MC between 700 and 900 MeV

  11. f0 signal in M(pp) spectrum and in FB asymmetry

  12. (3) Upper limit for h p+p- • Expected signal: • Gaussian m = 547.3 MeV • s = 1.33 MeV • Ns = -22  24 Ns < 21.1 (90%C.L.) Nh = 1.43  107 (from 3p0 counting)  BR( h  p+p-) < 8.9  10-6 • Comments: • Factor 37 improvement respect to previous limit • The negative fluctuation helps !

  13. Conclusions: Perspectives for publication and presentation at conferences: (1) The fit of the M(pp) spectrum is in “final shape”; (2) The FB-asymmetry reinforces the f0 signal BUT does not add any further insight: needs “theoretical support”. (3) The upper limit is also in “final shape”: discussion on the way to extract the limit are welcome.

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