Measurement of the top quark mass in the dileptonic t t-bar decay channel using the mass observables M[bl], M[T2], and M[blnu] in pp collisions at sqrt(s) = 8 TeV

CMS;Bakhshiansohi, Hamed;Bondu, Olivier;Brochet, Sébastien;Wertz, Sébastien;et.al.
(2017) Physical Review D — Vol. D96, p. 32002 (2017)

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Authors
  • CMSUCLouvain
    Author
  • Bakhshiansohi, HamedUCLouvain
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  • Bondu, OlivierUCLouvain
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  • Brochet, SébastienUCLouvain
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  • Caudron, AdrienUCLouvain
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  • de Visscher, SimonUCLouvain
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  • Delcourt, MartinUCLouvain
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  • Author
  • Author
  • Jafari, AbidehUCLouvain
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  • Komm, MatthiasUCLouvain
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  • Krintiras, GeorgiosUCLouvain
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  • Author
  • Magitteri, AlessioUCLouvain
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  • Mertens, AlexandreUCLouvain
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  • Musich, MarcoUCLouvain
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  • Piotrzkowski, KrzysztofUCLouvain
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  • Author
  • Selvaggi, MicheleUCLouvain
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  • Vidal Maroño, MiguelUCLouvain
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  • Wertz, Sébastienorcid-logoUCLouvain
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  • et. al.
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Abstract
A measurement of the top quark mass (M[t]) in the dileptonic t t-bar decay channel is performed using data from proton-proton collisions at a center-of-mass energy of 8 TeV. The data was recorded by the CMS experiment at the LHC and corresponding to an integrated luminosity of 19.7 +/- 0.5 inverse femtobarns. Events are selected with two oppositely charged leptons (l = e, mu) and two jets identified as originating from b quarks. The analysis is based on three kinematic observables whose distributions are sensitive to the value of M[t]. An invariant mass observable, M[bl], and a `stransverse mass' observable, M[T2], are employed in a simultaneous fit to determine the value of M[t] and an overall jet energy scale factor (JSF). A complementary approach is used to construct an invariant mass observable, M[blnu], that is combined with M[T2] to measure M[t]. The shapes of the observables, along with their evolutions in M[t] and JSF, are modeled by a nonparametric Gaussian process regression technique. The sensitivity of the observables to the value of M[t] is investigated using a Fisher information density method. The top quark mass is measured to be 172.22 +/- 0.18 (stat) +0.89/-0.93 (syst) GeV.
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Citations

CMS, Bakhshiansohi, H., Bondu, O., Brochet, S., Bruno, G., Caudron, A., de Visscher, S., Delaere, C., Delcourt, M., François, B., Giammanco, A., Jafari, A., Komm, M., Krintiras, G., Lemaitre, V., Magitteri, A., Mertens, A., Musich, M., Piotrzkowski, K., et al. (2017). Measurement of the top quark mass in the dileptonic t t-bar decay channel using the mass observables M[bl], M[T2], and M[blnu] in pp collisions at sqrt(s) = 8 TeV. Physical Review D, D96, 32002. https://doi.org/10.1103/PhysRevD.96.032002 (Original work published 2017)