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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 [ - PowerPoint PPT Presentation
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Update of at large angle (LNF 20/02/2004)
See: C.Bini, S.Ventura KLOE Memo 284C.Bini, B.Di Micco KLOE Memo 285
(1) Results of the fit(2) Forward-Backward asymmetry(3) Upper limit on +-
(1) Results of the fit
N(Q) = K [FISR(Q, M, , , ) + FFSR(Q) + Ff0(Q, gfKK, R, mf0) FINT(Q) +F(Q) + F3(Q) ]
K = fcoll(Q) (Q) L bfcoll(Q) = correction for collinear radiation (EVA)(Q) = efficiencyL = 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)
background: , - Achasov param.
- PDG abs. normalisation
- No interference (??)
3 background (survivingthe cuts):
- MC based abs. normalisation
- interference no interference + interference
Fit- Fit0 Fit+
2 / 481 755 597 750
g2fKK/4(GeV2) 1.52 0.13 0.98 0.07 0.16 0.28 0.02
R 1.69 0.15 7.83 0.32 0.50 6.9 0.6
Mf0 (MeV) 934 4 980.6 0.4 0.6 992.1 0.6
M (MeV) 774.3 0.2 773.6 0.2 0.8 773.4 0.2
(MeV) 145.3 0.5 144.6 0.3 1.2 145.4 0.3
( x 10-2) 0.169 0.005 0.176 0.005 0.008 0.191 0.015
-0.129 0.005 -0.115 0.002 0.004
-0.094 0.007
< 0.2 <0.16 <0.11
<0.06 0.31 0.08 0.30 0.06
(f0 +-) (MeV) 230 30.6 9.8
BR (6.6 0.6) x 10-5
Table with fit results:compare the 3 hypotheses;for fit0 hyp. stability estimate (second error)
Attempt to fit “forcing” f0 00 KLOE parameters:
Fit no Fit
g2fKK/4(GeV2) 1.29 2.79
R 3.22 4.00
Mf0 (MeV) 962 973Fit02 = 3700
Fit-2 = 1313
f0 +- after subtraction (red) vs. f0 00 “raw” spectrum (blue)
2 possible explanations:(1) spectrum has “another contribution”(2) has “another interference scheme”
(2) Forward-backward asymmetry+- system: odd terms (green) and even terms (brown)A(ISR) C-odd A(FSR) C-evenA(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 + - angle (depending on the cuts)
The integrated FB-asymmetry is (two definitions):
)90()90(
)90()90(1 oo
oo
NN
NN
)90()90()90()90(
2 oo
oo
NNNN
Comparison with MC: Eva + Geanfi reconstruction:
(red) data(triangles) MC gener.(open circles) MC recon.
data-MC discrepancy below 700 MeVClear f0 effectData > MC between 700 and 900 MeV
f0 signal in M() spectrum and in FB asymmetry
(3) Upper limit for +-
Expected signal: Gaussian = 547.3 MeV
= 1.33 MeV
Ns = -22 24 Ns < 21.1 (90%C.L.)
N = 1.43 107
(from 30 counting)
BR( -) < 8.9 10-6
Comments:(1) Factor 37 improvement respect to previous limit(2) The negative fluctuation helps !
Conclusions:Perspectives for publication and presentation at conferences:
(1) The fit of the M() 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.