The Matrix Element Method at Next-to-Leading Order

Understand

This paper presents an extension of the matrix element method to next-to-leading order in perturbation theory.

• To accomplish this we have developed a method to calculate next-to-leading order weights on an event-by-event basis.
• This allows for the definition of next-to-leading order likelihoods in exactly the same fashion as at leading order, thus extending the matrix element method to next-to-leading order.
• A welcome by-product of the method is the straightforward and efficient generation of unweighted next-to-leading order events.