# The soft drop groomed jet radius at NLL

## TL;DR

This paper develops a theoretical framework for calculating the soft drop groomed jet radius at NLL accuracy, including resummation of large and non-global logarithms, with results matching simulations and predictions for collider experiments.

## Contribution

It introduces a factorization formalism for the groomed jet radius at NLL and resums all relevant logarithms, including non-global effects, providing precise predictions for collider physics.

## Key findings

- Good agreement with Pythia 8 simulations.
- Resummation of non-global logarithms including clustering effects.
- Theoretical predictions applicable to LHC and RHIC.

## Abstract

We present results for the soft drop groomed jet radius $R_g$ at next-to-leading logarithmic accuracy. The radius of a groomed jet which corresponds to the angle between the two branches passing the soft drop criterion is one of the characteristic observables relevant for the precise understanding of groomed jet substructure. We establish a factorization formalism that allows for the resummation of all relevant large logarithms, which is based on demonstrating the all order equivalence to a jet veto in the region between the boundaries of the groomed and ungroomed jet. Non-global logarithms including clustering effects due to the Cambridge/Aachen algorithm are resummed to all orders using a suitable Monte Carlo algorithm. We perform numerical calculations and find a very good agreement with Pythia 8 simulations. We provide theoretical predictions for the LHC and RHIC.