Hi,
I realised that in some cases after doing a likelihood fit and extracting the number of signal events, I find the error to be way bigger than the actual number of signal events. (As you can see in the photo attached)
I’m doing a Gaussian fit and I let the parameters float. For a J/psi fit :
RooRealVar mean1("#mu","mean of gaussians",3.097,3.096,3.098);
RooRealVar sigma1("#sigma","width of gaussians",0.0048,0.003,0.005);
RooGaussian sig1("sig1", "sig1", x, mean1, sigma1);
RooRealVar a0("a0","a0",0.0005,-2.,1.) ;
Could you please let me know if I’m doing something wrong that contributes to this big error on the number of signal events ? Can I avoid it?