Bibcode
Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; König, A.; Krätschmer, I.; Liko, D.; Matsushita, T.; Mikulec, I.; Rabady, D.; Rad, N.; Rahbaran, B.; Rohringer, H.; Schieck, J.; Strauss, J.; Waltenberger, W.; Wulz, C.-E.; Dvornikov, O.; Makarenko, V.; Mossolov, V.; Suarez Gonzalez, J.; Zykunov, V.; Shumeiko, N.; Alderweireldt, S.; De Wolf, E. A.; Janssen, X.; Lauwers, J.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; Daci, N.; De Bruyn, I.; Deroover, K.; Lontkovskyi, D.; Lowette, S.; Moortgat, S.; Moreels, L.; Olbrechts, A.; Python, Q.; Skovpen, K.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Parijs, I.; Brun, H.; Clerbaux, B.; De Lentdecker, G.; Delannoy, H.; Fasanella, G.; Favart, L.; Goldouzian, R.; Grebenyuk, A.; Karapostoli, G.; Lenzi, T.; Léonard, A.; Luetic, J.; Maerschalk, T.; Marinov, A.; Randle-conde, A.; Seva, T.; Vander Velde, C.; Vanlaer, P.; Vannerom, D.; Yonamine, R.; Zenoni, F.; Zhang, F.; Cimmino, A.; Cornelis, T.; Dobur, D.; Fagot, A.; Gul, M.; Khvastunov, I.; Poyraz, D.; Salva, S.; Schöfbeck, R.; Tytgat, M.; Van Driessche, W.; Yazgan, E.; Zaganidis, N.; Bakhshiansohi, H.; Beluffi, C.; Bondu, O. et al.
Bibliographical reference
Physics Letters B, Volume 772, p. 336-358.
Advertised on:
9
2017
Citations
7
Refereed citations
6
Description
A search for events containing four top quarks (t t bar t t bar) is
reported from proton-proton collisions recorded by the CMS experiment at
√{ s} = 13 TeV and corresponding to an integrated luminosity of 2.6
fb-1. The analysis considers the single-lepton (e or
μ)+jets and the opposite-sign dilepton
(μ+μ-,
μ±e∓, or
e+e-)+jets channels. It uses boosted decision
trees to combine information on the global event and jet properties to
distinguish between t t bar t t bar and t t bar production. The number
of events observed after all selection requirements is consistent with
expectations from background and standard model signal predictions, and
an upper limit is set on the cross section for t t bar t t bar
production in the standard model of 94 fb at 95% confidence level (10.2
× the prediction), with an expected limit of 118 fb. This is
combined with the results from the published CMS search in the same-sign
dilepton channel, resulting in an improved limit of 69 fb at 95%
confidence level (7.4 × the prediction), with an expected limit
of 71 fb. These are the strongest constraints on the rate of t t bar t t
bar production to date.