sFit: a method for background subtraction in maximum likelihood fit

Understand

This paper presents a statistical method to subtract background in maximum likelihood fit, without relying on any separate sideband or simulation for background modeling.

• The method, called sFit, is an extension to the sPlot technique originally developed to reconstruct true distribution for each date component.
• The sWeights defined for the sPlot technique allow to construct a modified likelihood function using only the signal probability density function and events in the signal region.
• Contribution of background events in the signal region to the likelihood function cancels out on a statistical basis.