Biagio Di Micco13/02/ Radiative Phi Decays Meeting 1  Biagio Di Micco Università degli Studi di Roma III results

Biagio Di Micco13/02/ Radiative Phi Decays Meeting 2 Background expected from MC study  2   (after reproduction of functional shape) a 0  0   f 0  0    0   0  0    0     0  e + e -  (90% C.L.) 4 Expected (in 140 pb -1 of data) MC sample after cuts

Biagio Di Micco13/02/ Radiative Phi Decays Meeting 3 M  0  distribution for MC background  0  MeV  2  0   0   0  0  f 0  0  0 all

Biagio Di Micco13/02/ 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  = MeV  = 14.8 MeV DATA MC expected M  0  after kinematic fit in  0   4  ipotesis. MeV

Biagio Di Micco13/02/ 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

Biagio Di Micco13/02/ 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]

Biagio Di Micco13/02/ Radiative Phi Decays Meeting 7 E1 vs. E2 distribution (2001)  2   ? bhabha? Huge not predicted by MC E1 MeV MeV E2 E1 MeV

Biagio Di Micco13/02/ Radiative Phi Decays Meeting 8 Be aware of the background problem Upper limit 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  | > 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

Biagio Di Micco13/02/ Radiative Phi Decays Meeting 9 M  distribution in  hypothesis MeV M  CUT: |M  -135| > 20 DATA (2001)

Biagio Di Micco13/02/ 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

Biagio Di Micco13/02/ 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

Biagio Di Micco13/02/ Radiative Phi Decays Meeting 12 M 2  combinatorial in 4  hypothesis DATA (2001) MC CUT: M  < 125 M  > 155 MeV M 

Biagio Di Micco13/02/ Radiative Phi Decays Meeting 13 M 2  combinatorial in 4  hypothesis DATA (2001) MC CUT: M  < 125 M  > 155 MeV M 

Biagio Di Micco13/02/ 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 tt tt

Biagio Di Micco13/02/ Radiative Phi Decays Meeting 15  2 of the 4  kinematic fit. DATA (2001) MC CUT:  2 < 8 MeV M 

Biagio Di Micco13/02/ Radiative Phi Decays Meeting 16 Be aware of the background problem Upper limit 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  | > 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

Biagio Di Micco13/02/ 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 MeV

Biagio Di Micco13/02/ 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)  MeV -1 a =  N tot =966

Biagio Di Micco13/02/ 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.) = a( 90% C.L.) = Br(  ) =  (PDG 2002)   = (3.1  0.2)  b L = 166 pb -1 (trgmon lum) Br(  3  ) < 2.37  (90% C.L) Br(  3  ) < 2.74  (95% C.L.)

Biagio Di Micco13/02/ 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)  MeV -1 a =  N tot =1517

Biagio Di Micco13/02/ 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.) = a( 90% C.L.) = Br(  ) =  (PDG 2002)   = (3.1  0.2)  b L = 280 pb -1 (trgmon lum) Br(  3  ) < 2.56  (90% C.L) Br(  3  ) < 2.86  (95% C.L.)

Biagio Di Micco13/02/ 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

Biagio Di Micco13/02/ Radiative Phi Decays Meeting 23    E  2 overlapped Phase Space Quark Box model GeV

Biagio Di Micco13/02/ Radiative Phi Decays Meeting 24    vs. E  2 Phase Space Quark Box model GeV

Biagio Di Micco13/02/ Radiative Phi Decays Meeting 25  Phase space Quark Box model GeV 2  art = 0.70 eV  gen =0.71 eV