Abstract

This paper presents a measurement of the polarisation of τ leptons produced in Z/γ∗→ττ decays which is performed with a dataset of proton—proton collisions at s√=8 TeV, corresponding to an integrated luminosity of 20.2 fb −1 recorded with the ATLAS detector at the LHC in 2012. The Z/γ∗→ττ decays are reconstructed from a hadronically decaying τ lepton with a single charged particle in the final state, accompanied by a τ lepton that decays leptonically. The τ polarisation is inferred from the relative fraction of energy carried by charged and neutral hadrons in the hadronic τ decays. The polarisation is measured in a fiducial region that corresponds to the kinematic region accessible to this analysis. The τ polarisation extracted over the full phase space within the Z/γ∗ mass range of 66 <mZ/γ∗< 116 GeV is found to be Pτ=−0.14±0.02(stat)±0.04(syst) . It is in agreement with the Standard Model prediction of Pτ=−0.1517±0.0019 , which is obtained from the ALPGEN event generator interfaced with the PYTHIA 6 parton shower modelling and the TAUOLA τ decay library.

Autore Pugliese

• Gorini Edoardo , Spagnolo Stefania Antonia , Ventura Andrea

Tutti gli autori

• Aaboud M. , Chiodini G. , Gorini E. , Primavera M. , Spagnolo S. , Ventura A. , Atlas Collaboration

Titolo volume/Rivista

THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS

Anno di pubblicazione

2018

ISSN

1434-6044

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

Non Disponibile

Numero di citazioni Scopus

Non Disponibile

0

Ultimo Aggiornamento Citazioni

28/04/2018

Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile