TauSpinner: a tool for simulating CP effects in H to tau tau decays at LHC

Abstract

In this paper, we discuss application of the TauSpinner package as a simulation tool for measuring the CP state of the newly discovered Higgs boson using the transverse spin correlations in the H to tau tau decay channel. We discuss application for its main background Z/gamma* to tau tau as well. The TauSpinner package allows one to add, with the help of weights, transverse spin correlations corresponding to any mixture of scalar/pseudoscalar state, on already existing events using information from the kinematics of outgoing tau leptons and their decay products only. This procedure can be used when polarimetric vectors of the taus decays and density matrix for tau-pair production are not stored with the event sample. We concentrate on the well-defined effects for the Higgs (or Higgs-like scalar) decays, which are physically separated from the production processes. TauSpinner also allows to reintroduce (or remove) spin correlations to events from Drell-Yan Z/gamma* to tau tau process, the main background for the Higgs parity observables, again with the help of weights only. From the literature, we recall well-established observables, developed for measuring the CP of the Higgs, and use them as benchmarks for illustrating applications of the TauSpinner package. We also include a description of the code and prepared testing examples.

1+18 pages,4 figures

References in corpus (7)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• Study of the mass and spin-parity of the Higgs boson candidate via its decays to Z boson pairs
• Determining the CP parity of Higgs bosons at the LHC in their tau decay channels
• Determining the CP parity of Higgs bosons at the LHC in the $\tau$ to 1-prong decay channels
• NLO corrections to hard process in QCD shower -- proof of concept
• Gauge invariant sub-structures of tree-level double-emission exact QCD spin amplitudes

Cited by in corpus (3)

• Potential for optimizing Higgs boson CP measurement in H to tau tau decay at LHC and ML techniques
• Deep learning approach to the Higgs boson CP measurement in H to tau tau decay and associated systematics
• Tau lepton production and decays: perspective of multi-dimensional distributions and Monte Carlo methods