Presentazione di PowerPoint

1
Measurement of f-leptonic width in ee- ?
ee-, mm- processes
Motivations

• determines the total f production cross section
  in ee- annihilation and the f-decay BRs
• in VMD model provides photon-f coupling costant
  gfg
• plays an important role for hadronic
  contribution to photon vacuum polarization
• provides test for universality of leptonic
  coupling costant and for quark charge assignement
  in f meson

Dafne 2004
M. Dreucci - lnf
2
Observables

• Bhabha events
• ?ee,f sint

Center of mass energy below and above MF
affects in opposite way sint For this reason
our analysis uses only 3 energy points Mf
, MfGf/2

• muon production
• ?mm,f sint

Dafne 2004
M. Dreucci - lnf
3
Experimental data fit functions

• For Bhabha, to enhance sensitivity, we measure
  AFB asymmetry
• We use a B.W. cross section, corrected for ISR,
  FSR and BES
• The fit parameters are Gee , MF and AoFB

• For muons we measure directly cross section
• We use a B.W. cross section, corrected for ISR,
  FSR and BES
• The fit parameters are ?GeeGmm , MF and so

? for more details see the poster

Dafne 2004
M. Dreucci - lnf