Ústav technické a experimentální fyziky Institute of Experimental and Applied Physics

Measurement of tau polarisation in Z/gamma* -> tau tau decays in proton-proton collisions at root s=8 TeV with the ATLAS detector

NázevTitle
Measurement of tau polarisation in Z/gamma* -> tau tau decays in proton-proton collisions at root s=8 TeV with the ATLAS detectorMeasurement of tau polarisation in Z/gamma* -> tau tau decays in proton-proton collisions at root s=8 TeV with the ATLAS detector
Druh výsledkuResult type
Článek v časopiseJournal article
AutořiAuthors
M. Aaboudd, G. Aad, B. Abbott, O. Abdinov, B. Ali, K. Augsten, D. Caforio, P. Gallus, M. Havránek, Z. Hubáček, M. Myška, S. Pospíšil, V. Šimák, T. Slavíček, K. Smolek, M. Solar, A. Sopczak, M. Suk, V. Vacek, P. Vokáč, V. Vrba
DOIDOI
10.1140/epjc/s10052-018-5619-1
Časopis / citaceJournal / citation
European Physical Journal C. 2018, 78(2), ISSN 1434-6044.
RokYear
2018
JazykLanguage
eng
WoSWoS
000426484600001
ScopusScopus
2-s2.0-85042560791
RIVRIV
RIV/68407700:21220/18:00326082!RIV19-MSM-21220___
ProjektProject
Základní výzkum fyziky vysokých energií v mezinárodním experimentu ATLAS na hadronovém urychlovači LHC v laboratoři CERN.Fundamental research in the field of high energy physics in the ATLAS experiment at the hadron collider LHC at CERN laboratory.; Získávání nových poznatků o mikrosvětě v infrastruktuře CERNAcquiring new pieces of knowledge about micro-world in CERN research infrastructure

AbstraktAbstract

This paper presents a measurement of the polarisation of tau leptons produced in Z/gamma* -> tau tau decays which is performed with a dataset of proton-proton collisions at root 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/gamma* -> tau tau decays are reconstructed from a hadronically decaying tau lepton with a single charged particle in the final state, accompanied by a tau lepton that decays leptonically. The tau polarisation is inferred from the relative fraction of energy carried by charged and neutral hadrons in the hadronic tau decays. The polarisation is measured in a fiducial region that corresponds to the kinematic region accessible to this analysis. The tau polarisation extracted over the full phase space within the Z/gamma* mass range of 66 < mZ/gamma* < 116GeVis found to be P-tau = -0.14 +/- 0.02(stat)+/- 0.04(syst). It is in agreement with the Standard Model prediction of Pt = -0.1517 +/- 0.0019, which is obtained from the ALP-GEN event generator interfaced with the PYTHIA 6 parton shower modelling and the TAUOLA tau decay library.

This paper presents a measurement of the polarisation of tau leptons produced in Z/gamma* -> tau tau decays which is performed with a dataset of proton-proton collisions at root 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/gamma* -> tau tau decays are reconstructed from a hadronically decaying tau lepton with a single charged particle in the final state, accompanied by a tau lepton that decays leptonically. The tau polarisation is inferred from the relative fraction of energy carried by charged and neutral hadrons in the hadronic tau decays. The polarisation is measured in a fiducial region that corresponds to the kinematic region accessible to this analysis. The tau polarisation extracted over the full phase space within the Z/gamma* mass range of 66 < mZ/gamma* < 116GeVis found to be P-tau = -0.14 +/- 0.02(stat)+/- 0.04(syst). It is in agreement with the Standard Model prediction of Pt = -0.1517 +/- 0.0019, which is obtained from the ALP-GEN event generator interfaced with the PYTHIA 6 parton shower modelling and the TAUOLA tau decay library.