Calculating the primary Lund Jet Plane density

Understand

The Lund-jet plane has recently been proposed as a powerful jet substructure tool with a broad range of applications.

• In this paper, we provide an all-order single logarithmic calculation of the primary Lund-plane density in Quantum Chromodynamics, including contributions from the running of the coupling, collinear effects for the leading parton, and soft logarithms that account for large-angle and clustering effects.
• We also identify a new source of clustering logarithms close to the boundary of the jet, deferring their resummation to future work.
• We then match our all-order results to exact next-to-leading order predictions.