data sample: 130 pb - 1 (2001) + 250 pb - 1 (2002)

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f  f 0 g  p + p - g. Data sample: 130 pb - 1 (2001) + 250 pb - 1 (2002). C. Bini S. Ventura. Spectra of 2001 and 2002 data Evaluation of luminosity and number of events Fit of the 2001+2002 spectrum Branching Ratio of f  f 0 g  p + p - g. Invariant Mass M pp Spectra. - PowerPoint PPT Presentation

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  • Data sample: 130 pb-1 (2001) + 250 pb-1 (2002)

    Spectra of 2001 and 2002 data

    Evaluation of luminosity and number of events

    Fit of the 2001+2002 spectrum

    Branching Ratio of f f0g p+p-gf f0g p+p-gC. Bini S. Ventura

  • Invariant Mass Mpp Spectra20012002

  • Evaluation of luminosity

    A run is included in the evaluation of the total luminosity ifR is compatible with the average. N is the number of events after selection.

    The mean value of R is 1.75 events per nb-1 for 2001 and 2002 data.We have the ratio between number of events and integrated luminosityfor every run:

  • Nrun 2001Nrun 2002

    yearNumber of eventsLuminosity (nb-1)Rejected luminosity (nb-1) 20011894241080261460020024093642336565900

  • Using the values of luminosity found we can compare the spectra of 2001 and 2002.20012002

  • Fit of the spectra 2001+2002 The function for the fit has 4 terms:

    Initial State Radiation AchasovFinal State Radiation Achasovf f0g p+p-g Giovannella-MiscettiInterference with Final Achasov-Giovannella-Miscetti State Radiation We have a fit for each possible sign of the interference term.

  • The function for the fit depends on 9 parameters:(ds/dM)= fisr(x, mr ,Gr , mw ,Gw , a , b) + ffsr(x, mr ,Gr , mw ,Gw , a , b) +

    ff0(x, g2f0KK/4p , g2f0KK/g2f0p+p- , mf0 ) +

    fint(x, g2f0KK/4p , g2f0KK/g2f0p+p- , mf0 , mr ,Gr , mw ,Gw , a , b)

    The function is multiplied by the efficiency and the luminosity: f(x) = (ds/dM) e T L DM Ce TT is a factor that takes into account the cut on the polar angle of the pionsDM is the bin sizeC an overall factor : 0.8In the f0-term we replace G(f0 p0p0) with: G(f0 p+p-) = 2 G(f0 p0p0)

  • Destructive InterferenceALL ISR FSR f0 INTfisr + ffsr + ff0 - fint

  • No InterferenceALL ISR FSR f0 INTfisr + ffsr + ff0

  • Constructive InterferenceALL ISR FSR f0 INTfisr + ffsr + ff0 + fint

  • Results of the fit

    Interference Destructive No int. Constructive PDG g2f0KK/4p (GeV2) 0.39 0.02 0.29 0.02 0.23 0.01 g2f0KK/g2f0p+p- 3.06 0.12 3.49 0.15 3.75 0.18 mf0 (MeV) 975.10 0.62 980.16 0.57 984.17 0.48 980 10 mr (MeV) 774.27 0.19 774.18 0.19 774.15 0.47 771.1 0.9 Gr (MeV) 140.60 0.29 140.98 0.30 141.41 0.31 149.2 0.7 mw (MeV) 782.09 0.17 782.11 0.16 782.10 0.17 782.57 0.12 Gw (MeV) 8.41 0.43 8.48 0.53 8.57 0.54 8.44 0.09 a (10-2) (0.162 0.007) (0.163 0.009) (0.16270.009) b -0.145 0.001 -0.146 0.001 -0.147 0.001 c2/ndf 452 / 342 479 / 342 537 / 342

  • For the case of destructive interference we show the variable:

  • Estimate of BR(f f0g p+p-g)Nexp( f0) is the number of ff0g events calculated integrating thecontribution of the f0 to the total function without the efficiency. s(f) = 3.34 mbL = 342 pb-1

    Interference Nexp( f0) BR(f f0g p+p-g)Destructive 100338 8.79 10-5Zero 64974 5.69 10-5Constructive 44728 3.92 10-5

  • Comparison with the Giovannella-Miscetti results:Giovannella Miscetti found this value:BR(f f0g p0p0g) = (1.49 0.07) 10-4We expect BR(f f0g p+p-g) ~ 2 BR(f f0g p0p0g) Instead we find:BR(f f0g p+p-g) ~ 0.58 BR(f f0g p0p0g)

    Giovannella-Miscetti g2f0KK/4p (GeV2) 2.79 0.12 0.39 0.02 g2f0KK/g2f0p+p- 4.00 0.14 3.06 0.12 mf0 (MeV) 973 1 975.10 0.62

  • Using the parameters of Giovannella-Miscetti in the function for the fitthere is not agreementwith data.Constructive int.Zero int.Destructive int.

  • = 25

    = 45

    = 65Spectrum of the data and function for different values of the photon polar angle range:The function describes quite well how the spectrum changes varying the photon polar angle range.

  • Fit with contribution of the sThe parameterization of f (f0+s) g p+p-g is taken from Giovannella-Miscetti We include the term of interference between f s g p+p-gand the Final State Radiation.The mass and width of the s are fixed at: ms= 480 MeV Gs= 324 MeV

    We have only a new free parameter for the fit:gfsg

  • Results of the fit with the s contributionIn the case of destructive interference

    Without s With s g2f0KK/4p (GeV2) 0.39 0.02 0.56 0.02 g2f0KK/g2f0p+p- 3.06 0.12 3.38 0.05 mf0 (MeV) 975.10 0.62 976.54 0.44 gfsg (10-2 MeV) 6.99 0.05 mr (MeV) 774.27 0.19 773.93 0.19 Gr (MeV) 140.60 0.29 138.13 0.51 mw (MeV) 782.09 0.17 782.01 0.16 Gw (MeV) 8.41 0.43 8.17 0.50 a (10-2) (0.162 0.007) 0.159 0.005 b -0.145 0.001-0.161 0.008 c2/ndf 452 / 342 476/342

  • Conclusions

    the spectrum is well described by the function in the case of destructive interference

    in the case of destructive interference we have: without the s contribution we find: BR(f f0g p+p-g) = 8.79 10-5 ~ 0.58 BR(f f0g p0p0g)

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