Measurement of the W boson polarisation in t(t)over-barevents from pp collisions at root s=8 TeV in the lepton plus jets channel with ATLAS
- NázevTitle
- Measurement of the W boson polarisation in t(t)over-barevents from pp collisions at root s=8 TeV in the lepton plus jets channel with ATLASMeasurement of the W boson polarisation in t(t)over-barevents from pp collisions at root s=8 TeV in the lepton plus jets channel with ATLAS
- Druh výsledkuResult type
- Článek v časopiseJournal article
- AutořiAuthors
- M. Aaboud, G. Aad, B. Abbott, J. Abdallah, B. Ali, K. Augsten, D. Caforio, P. Gallus, Z. Hubáček, M. Myška, S. Pospíšil, F. Seifert, V. Šimák, T. Slavíček, K. Smolek, M. Solar, A. Sopczak, V. Sopko, M. Suk, V. Vacek, M. Šuta, P. Vokáč, M. Zeman
- Klíčová slovaKeywords
- top-quark production, parton distribution, hadron colliders, Pair production, resummation, lhc
- ExperimentCollaboration
- ATLAS
- DOIDOI
- 10.1140/epjc/s10052-017-4819-4
- Časopis / citaceJournal / citation
- The European Physical Journal C 77(4), 264 (2017) · ISSN 1434-6044
- RokYear
- 2017
- JazykLanguage
- eng
- ZáznamyRecords
- ProjektProject
- Získávání nových poznatků o mikrosvětě v infrastruktuře CERNAcquiring new pieces of knowledge about micro-world in CERN research infrastructure
- CitovánoCited by
- 130 (INSPIRE-HEP)
- Plný text (open access)Full text (open access)
- https://link.springer.com/content/pdf/10.1140%2Fepjc%2Fs10052-017-4819-4.pdf
- Citace ke staženíDownload citation
- TXT · BibTeX
AbstraktAbstract
This paper presents a measurement of the polarisation of W bosons from t (t) over bar t decays, reconstructed in events with one high-p(T) lepton and at least four jets. Data from pp collisions at the LHC were collected at root s = 8 TeV and correspond to an integrated luminosity of 20.2 fb(-1). The angle theta* between the b-quark from the top quark decay and a direct W boson decay product in the W boson rest frame is sensitive to the W boson polarisation. Two different W decay products are used as polarisation analysers: the charged lepton and the down-type quark for the leptonically and hadronically decaying W boson, respectively. The most precise measurement of the W boson polarisation via the distribution of cos theta* is obtained using the leptonic analyser and events in which at least two of the jets are tagged as b-quark jets. The fitted fractions of longitudinal, left-and right-handed polarisation states are F-0 = 0.709 +/- 0.019, F-L = 0.299 +/- 0.015 and F-R = - 0.008 +/- 0.014, and are the most precisely measured W boson polarisation fractions to date. Limits on anomalous couplings of the W tb vertex are set.
This paper presents a measurement of the polarisation of W bosons from t (t) over bar t decays, reconstructed in events with one high-p(T) lepton and at least four jets. Data from pp collisions at the LHC were collected at root s = 8 TeV and correspond to an integrated luminosity of 20.2 fb(-1). The angle theta* between the b-quark from the top quark decay and a direct W boson decay product in the W boson rest frame is sensitive to the W boson polarisation. Two different W decay products are used as polarisation analysers: the charged lepton and the down-type quark for the leptonically and hadronically decaying W boson, respectively. The most precise measurement of the W boson polarisation via the distribution of cos theta* is obtained using the leptonic analyser and events in which at least two of the jets are tagged as b-quark jets. The fitted fractions of longitudinal, left-and right-handed polarisation states are F-0 = 0.709 +/- 0.019, F-L = 0.299 +/- 0.015 and F-R = - 0.008 +/- 0.014, and are the most precisely measured W boson polarisation fractions to date. Limits on anomalous couplings of the W tb vertex are set.