EERAD3: Event shapes and jet rates in electron-positron annihilation at order $α_s^3$

TL;DR

EERAD3 provides NNLO QCD predictions for event shapes and jet rates in $e^+e^-$ annihilation by assembling three-, four-, and five-parton final states with antenna subtraction and a VEGAS-based Monte Carlo integration. The framework delivers perturbative coefficients $A$, $B$, and $C$ for a broad class of infrared-safe observables, supports scale variation through an auxiliary tool, and offers modular components to add new observables or jet algorithms. By delivering precise, validated predictions for LEP-era observables and providing a flexible interface, EERAD3 enables stringent tests of perturbative QCD and precise determinations of $α_s$. The program structure and detailed usage instructions facilitate reuse and extension, making it a valuable resource for high-precision QCD phenomenology in electron-positron annihilation.

Abstract

The program EERAD3 computes the parton-level QCD contributions to event shapes and jet rates in electron-positron annihilation through to order $α_s^3$. For three-jet production and related observables, this corresponds to next-to-next-to-leading order corrections, and allows for precision QCD studies. We describe the program and its usage in detail.

Figures (1)

• Figure 1: Schematic structure of EERAD3. The event shape observables $C,y_{23},T$ are for illustration, other observables can be calculated as well.