RooFit:how to set cutoff less than m0 when using RooArgusBG

I am a newcomer of roofit,and now I have a problem about RooArgusBG.

RooRealVar argpar("argpar","argus shape parameter",-20.0,-100.,-1.) ; RooArgusBG background("background","Argus PDF",mes,RooConst(5.291),argpar) ;
Like above,there is a cut off at 5.291,witch means the p.d.f will be 0 in the range greater than 5.291.But now I have a dataset which the p.d.f should be 0 less than 2.5.So,how should I set thus cutoff? Or,whether there is other methods to set thus p.d.f?

Best Regards


You can set the parameter value either when you build the class, or use a constant RooRealVar and you can set its value later on, using RooRealVar::setVal

Best Regards