The fit function is:

In Mass Window around J/psi (+- 3 sigma of mean mass):

bg=((1-F1)*(fPlus*gplus + fMnus*gmnus+(1-fPlus-fMnus)*pgBg))
sig=(F1*(Fb*se+(1-Fb)*pgSig))

bg=fPlus*gplus + fMnus*gmnus+ (1-fPlus-fMnus)*pgBg

• gplus and gminus are the positive and negative background exponentials
• pgBg is the prompt background gaussian
• pgSig is the prompt signal gaussian
• se is the signal exponential convoluted with a gaussian smearing.

• tau, blife, in se
• Lambda+, positive background lifetime in gplus
• Lambda-, negative background lifetime in gminus
• F+ (fPlus), Fraction of positive background lifetime
• F- (fMnus), Fraction of negative background lifetime
• Scale: sigma multiplier of pgBg, pgSig, and se. Thus, the resolution used in the convolution comes from the background and prompt gaussian widths.
• F1 Fraction of real jpsi's in mass window.
• Fb Fraction of jpsi from B in mass window