My question is about Chebyshev polynomials.
For invariant mass fit I am doing gaus + chebyshev fit and bellow is the background determination part from my script.

My question is if I do (a0,a1) it’s supposed to be a line(right?) fit for background, so what is the a0 parameter by itself? Is it like a degree? If I take only a0 for my fit what will it do with background?
I’ll be very thankful if someone can explain me this.

Hi @Gayane_Ghevondyan,
thanks for reaching out! Here you’re expressing your background as a polynomial b(x)=a0+a1*x+a2*x^2+...+a_n*x^n, so if you give a list of length n you’ll get a polynomial background of degree n-1. If you specify two parameters you’ll get a line and only one parameter will turn out into a constant.
Hope this helps.
Cheers,
Monica

Thanks a lot for your reply. And let me kindly ask, so if (a0,a1) together is a line fit, so what is the a0= -0.29 contribution for it? Is it like a slope for line? Because it can be seen from the picture that red line has some slop.