Peak and integrated resonance width dependence
= Peak and integrated resonance width dependence
At fixed entrance and exit <partial decay widths>, a resonance's peak <cross section> is proportional to their product divided by the square of its total width. Integrating a narrow Lorentzian over energy supplies one factor of the total width, leaving an inverse first power. Extracting a width from a peak ratio therefore differs from extracting it from an integrated ratio.