1/N*dN/d(pt) and 1/sigma* dsigma/d(pt)

Dear Root Experts,

I need your help. Any body can explain me what is the main difference between the following

1/N*dN/d(pt) and 1/sigma* dsigma/d(pt)

Is the same N=luminosity*Sigma.
If I want to normalize my histogram per entry per unite of Xaxis with say pt. What would be the quantity plotted on Y axis will it be 1/N*dN/d(pt) or some other quantity.

One thing more I want to get the area under the fitted histogram how can I get that area.

I would be indeed thank full to you.

Best Regards

Wajid Ali
National Center for Physics, Islamabad
Phone: 051-2077336 Received on Mon Jan 04 2010 - 06:32:11 CET