Measurement of the top-quark mass in the fully hadronic decay channel from ATLAS data at √s = 7 TeV

The mass of the top quark is measured in a data set corresponding to 4.6 fb<sup>-1</sup> of proton–proton collisions with centre-of-mass energy √ = 7 TeV collected by the ATLAS detector at the LHC. Events consistent with hadronic decays of top–antitop quark pairs with at least six jets i...

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Detalles Bibliográficos
Autores: Alconada Verzini, María Josefina, Alonso, Francisco, Anduaga, Xabier Sebastián, Dova, María Teresa, Monticelli, Fernando Gabriel, Wahlberg, Hernán Pablo, The ATLAS Collaboration
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2015
País:Argentina
Institución:Universidad Nacional de La Plata
Repositorio:SEDICI (UNLP)
Idioma:inglés
OAI Identifier:oai:sedici.unlp.edu.ar:10915/86811
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/86811
Access Level:acceso abierto
Palabra clave:Ciencias Exactas
Física
ATLAS
Fully hadronic
LHC
Proton–proton collisions
Top quark
Top-quark mass
Descripción
Sumario:The mass of the top quark is measured in a data set corresponding to 4.6 fb<sup>-1</sup> of proton–proton collisions with centre-of-mass energy √ = 7 TeV collected by the ATLAS detector at the LHC. Events consistent with hadronic decays of top–antitop quark pairs with at least six jets in the final state are selected. The substantial background from multijet production is modelled with data-driven methods that utilise the number of identified b-quark jets and the transverse momentum of the sixth leading jet, which have minimal correlation. The top-quark mass is obtained from template fits to the ratio of three-jet to dijet mass. The three-jet mass is calculated from the three jets produced in a top-quark decay. Using these three jets the dijet mass is obtained from the two jets produced in the W boson decay. The top-quark mass obtained from this fit is thus less sensitive to the uncertainty in the energy measurement of the jets. A binned likelihood fit yields a top-quark mass of mt = 175.1 ± 1.4 (stat.) ± 1.2 (syst.) GeV.