Two-loop Jet-Function and Jet-Mass for Top Quarks

Understand

We compute the two-loop heavy quark jet-function in the heavy quark limit.

• This is one of the key ingredients in next-to-next-to-leading order (NNLO) and next-to-next-to-leading-log order (NNLL) computations of the invariant mass distribution of top-jets at a future e+e- collider.
• The shape of the top invariant mass distribution is affected by large logs which we compute at NNLL order.
• Exploiting the non-abelian exponentiation theorem, a definition of the top jet-mass is given which is transitive and whose renormalization group evolution is determined by the cusp-anomalous dimension to all orders in perturbation theory.