Eur. Phys. J. C (2013) 73: 2489
https://doi.org/10.1140/epjc/s10052-013-2489-4

Special Article - Tools for Experiment and Theory

TauDecay: a library to simulate polarized tau decays via FeynRules and MadGraph5

¹ KEK Theory Center, and Sokendai, Tsukuba, 305-0801, Japan
² ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, Monash University, Melbourne, Victoria, 3800, Australia
³ Theoretische Natuurkunde and IIHE/ELEM, Vrije Universiteit Brussel, and International Solvay Institutes, Pleinlaan 2, 1050, Brussels, Belgium

^* e-mail: tong.li@monash.edu

Received: 21 January 2013
Revised: 26 May 2013
Published online: 12 July 2013

Abstract

TauDecay is a library of helicity amplitudes to simulate polarized tau decays, constructed in the FeynRules and MadGraph5 framework. Together with the leptonic mode, the decay library includes the main hadronic modes, τ→ν _τ +π, 2π, and 3π, which are introduced as effective vertices by using FeynRules. The model file allows us to simulate tau decays when the on-shell tau production is kinematically forbidden. We also demonstrate that all possible correlations among the decay products of pair-produced taus through a Z boson and a scalar/pseudoscalar Higgs boson are produced automatically. The program has been tested carefully by making use of the standard tau decay library Tauola.