Hi all,
I was wondering if anyone knows if the following is possible, it runs without errors but does not behave as I expect.
RooRealVar sigmean(“M_{B}”,“B mass”,5282,5277,5284,“MeV/c^{2}”);
RooRealVar sigsigma("#sigma_{B}",“B sigma”,13,0,30,“MeV/c^{2}”);
RooGaussian BSig_RF( “Bsig_RF”, “Signal Gaussian B RF Mass”, Donly_CM_M, sigmean, sigsigma );
// Fix ratio of Gaussians to MC
RooRealVar ratio(“ratio”,“Ratio of widths”,2.0,1.0,3.0);
RooGaussian const_ratio(“const_ratio”,"",ratio,RooFit::RooConst(2.0),RooFit::RooConst(0.1));
RooProduct sigsigma2("#sigma_{B}2",“B sigma2”,RooArgSet(sigsigma,const_ratio));
RooGaussian BSig_RF2( “Bsig_RF2”, “Signal Gaussian B RF Mass”, Donly_CM_M, sigmean, sigsigma2 );
So I have the parameter ratio that is used to calculate sigsigma2, and I wish to constrain the value of ratio. However, when I do this it always stays at the value I set here RooFit::RooConst(2.0).
The fit also contains other components so I assume the likelihood favours changing those rather than taking a penalty from changing const_ratio.
So basically I just wanted to know if anyone has successfully constrained a parameter passed to a RooProduct?
Cheers,
Mark
P.S. I know it isn’t a problem with constraints in general as I also constrain other things in the fit successfully.