TY  - SER
AU  - Tumasyan,Armen
AU  - Adam,Wolfgang
AU  - Borshch,Vladislav
AU  - Ivanchenko,Vladimir
AU  - Tcherniaev,Evgueni
AU  - Sirunyan,A.M.
TI  - Search for production of four top quarks in final states with same-sign or multiple leptons in proton-proton collisions at √s=13 TeV
KW  - топ-кварки
KW  - лептоны
KW  - протон-протонные столкновения
KW  - статьи в журналах
N1  - Библиогр.: 77 назв
N2  - The standard model (SM) production of four top
quarks (tt tt) in proton–proton collisions is studied by the
 CMS Collaboration. The data sample, collected during the
 2016–2018 data taking of the LHC, corresponds to an integrated
 luminosity of 137 fb−1 at a center-of-mass energy of
 13 TeV. The events are required to contain two same-sign
 charged leptons (electrons or muons) or at least three leptons,
 and jets. The observed and expected significances for the tt tt
 signal are respectively 2.6 and 2.7 standard deviations, and
 the tt tt cross section ismeasured to be 12.6+5.8
 −5.2 fb.The results
 are used to constrain the Yukawa coupling of the top quark
 to the Higgs boson, yt, yielding a limit of |yt/ySM
 t | < 1.7 at
 95% confidence level, where ySM
 t is the SMvalue of yt. They
 are also used to constrain the oblique parameter of the Higgs
 boson in an effective field theory framework, Hˆ < 0.12.Limits
 are set on the production of a heavy scalar or pseudoscalar
 boson in Type-II two-Higgs-doublet and simplified darkmatter
 models, with exclusion limits reaching 350–470 GeV and
 350–550 GeV for scalar and pseudoscalar bosons, respectively.
 Upper bounds are also set on couplings of the top
 quark to new light particles
UR  - http://vital.lib.tsu.ru/vital/access/manager/Repository/vtls:000795385
ER  -