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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 1 Biagio Di Micco Università degli Studi di Roma III 2001 - 2002 results
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 2 Background expected from MC study 2 129392 (after reproduction of functional shape) a 0 0 749 4582 f 0 0 0 2194 4592 0 0 0 2318 23255 0 197 6083 0 139 34 e + e - 13.6 - 80 (90% C.L.) 4 Expected (in 140 pb -1 of data) MC sample after cuts
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 3 M 0 distribution for MC background 0 MeV 2 0 0 0 0 f 0 0 0 all
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 4 M 0 distribution DATA-MC comparison (2001) 1) Normaliztion problem (bad luminosity estimation) 2) Shape problem, mainly at high values !! High discrepancy =783.90 MeV = 14.8 MeV DATA MC expected M 0 after kinematic fit in 0 4 ipotesis. MeV
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 5 4c - 3 kinematic fit (2001) 1) perform kinamtic fit on 3 constraining the total momentum 2) select the set with least 2 Prob( 2 > 2 0 ) CUT PROB > 0.05 E combinatorial 2 MeV
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 6 M 0 comparison DATA-DATA [P( 2 3 )>0.05] Compensation of the bad shape (2001) MeV DATA DATA [P( 2 3 )>0.05]
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 7 E1 vs. E2 distribution (2001) 2 ? bhabha? Huge not predicted by MC E1 MeV MeV E2 E1 MeV
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 8 Be aware of the background problem Upper limit 2001 - 2002 Selection cuts changed again !! (no cut on the number of photon below a given angle) Filfo - EVCL RAD 250 MeV < E < 480 MeV (E rad = 363 MeV) N good = 4 (Good: E > 30 MeV, t 21.6 ° ) > 15°, Etot (4 ) > 900 MeV |M -135| > 20 MeV M two photon mass after kinematic fit 4 E1 +E2 (two photon more energetic) > 800 MeV |E -362.2| > 8 MeV, |E -E ( 0 )| > 4.62 (after 3 kinematic fit, in reference frame) 2 3 > 25, M 152 MeV, T.D.W.T < 0.4 (wait a bit for explanation), 2 4 < 8
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 9 M distribution in hypothesis MeV M CUT: |M -135| > 20 DATA (2001)
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 10 Sum of the energy of the most energetic two photons MeV E1+E2 E1+E2 DATA (2001) MC CUT: E1+E2 < 800 MeV
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 11 Energy of photons (combinatorial) in the 3 hypothesis MeV E E DATA (2001) MC 2 0 CUT: |E-362.2| > 8 MeV |E-500| > 4.6 MeV
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 12 M 2 combinatorial in 4 hypothesis DATA (2001) MC CUT: M < 125 M > 155 MeV M
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 13 M 2 combinatorial in 4 hypothesis DATA (2001) MC CUT: M < 125 M > 155 MeV M
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 14 t between photons and the two photon which have less difference in the time of flight. DATA (2001) MC CUT: t < 0.4 ns ns tt tt
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 15 2 of the 4 kinematic fit. DATA (2001) MC CUT: 2 < 8 MeV M
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 16 Be aware of the background problem Upper limit 2001 - 2002 Selection cuts changed again !! (no cut on the number of photon below a given angle) Filfo - EVCL RAD 250 MeV < E < 480 MeV (E rad = 363 MeV) N good = 4 (Good: E > 30 MeV, t 21.6 ° ) > 15°, Etot (4 ) > 900 MeV |M -135| > 20 MeV M two photon mass after kinematic fit 4 E1 +E2 (two photon more energetic) > 800 MeV |E -362.2| > 8 MeV, |E -E ( 0 )| > 4.62 (after 3 kinematic fit, in reference frame) 2 3 > 25, M 152 MeV, T.D.W.T < 0.4 (wait a bit for explanation), 2 4 < 8
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 17 MC energy of the most energetic photon in the reference frame MeV Double gaussian fit Selected range to estimate upper limit 300 - 400 MeV
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 18 Fit result on 2001 data MeV Fitted function: N 1,N 2 normalization constants Fit results: a 1 = (-3.49 0.04) 10 -3 MeV -1 a = -0.013 0.017 N tot =966
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 19 Upper limit on 2001 data Total Events: 961 log(likelihood) a 95 % C.L 90 % C.L. a( 95% C.L.) = 0.037 a( 90% C.L.) = 0.032 Br( ) = 1.299 0.026 (PDG 2002) = (3.1 0.2) b L = 166 pb -1 (trgmon lum) Br( 3 ) < 2.37 10 -5 (90% C.L) Br( 3 ) < 2.74 10 -5 (95% C.L.)
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 20 Upper limit on 2002 data MeV Fitted function: N 1,N 2 normalization constants Fir results: a 1 = (-3.58 0.04) 10 -3 MeV -1 a = 0.006 0.014 N tot =1517
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 21 Fit result on 2002 data Total Events: 1512 log(likelihood) a 95 % C.L 90 % C.L. a( 95% C.L.) = 0.041 a( 90% C.L.) = 0.037 Br( ) = 1.299 0.026 (PDG 2002) = (3.1 0.2) b L = 280 pb -1 (trgmon lum) Br( 3 ) < 2.56 10 -5 (90% C.L) Br( 3 ) < 2.86 10 -5 (95% C.L.)
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 22 generator Biagio Di Micco Università degli Studi di Roma III Generator built according the article: SND: Nucl.Phys.B600:3, 2001 with the model of Ng Phys.Rev. D47:4939, 1993
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 23 E 2 overlapped Phase Space Quark Box model GeV
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 24 vs. E 2 Phase Space Quark Box model GeV
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Biagio Di Micco13/02/2003 - Radiative Phi Decays Meeting 25 Phase space Quark Box model GeV 2 art = 0.70 eV gen =0.71 eV
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