${{\boldsymbol t}}{{\overline{\boldsymbol t}}}$ ${{\boldsymbol t}}{{\overline{\boldsymbol t}}}$ Production Cross Section in ${{\boldsymbol p}}{{\boldsymbol p}}$ Collisions at $\sqrt {s }$ = 13 TeV INSPIRE search

VALUE (fb) CL% DOCUMENT ID TECN  COMMENT
• • • We do not use the following data for averages, fits, limits, etc. • • •
$<47$ 95 1
 2019 AP
ATLS ${{\mathit \ell}}$ + ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ channels
$<49$ 95 2
 2019 AP
ATLS combination of ATLAS
$13$ ${}^{+11}_{-9}$ 3
 2019 CN
CMS combination of CMS
$<48$ 95 4
 2019 CN
CMS ${{\mathit \ell}}$+jets, ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ +jets channels
$<69$ 95 5
 2018 CE
ATLS ${}\geq{}2{{\mathit \ell}}$(same sign) + $\not E_T$ + ${}\geq{}1{{\mathit b}}$j
$16.9$ ${}^{+13.8}_{-11.4}$ 6
 2018 BU
CMS ${{\mathit t}}$ ${{\overline{\mathit t}}}$ ${{\mathit t}}$ ${{\overline{\mathit t}}}$ $\rightarrow$ (same sign 2${{\mathit \ell}}$ or ${}\geq{}3{{\mathit \ell}}$) + ${}\geq{}$4 j (${}\geq{}2{{\mathit b}}$)
$<94$ 95 7
 2017 AB
CMS ${{\mathit \ell}}$+jets, ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}$ +jets channels
$<42$ 95 8
 2017 S
CMS (same sign 2${{\mathit \ell}})+\not E_T+{}\geq{}$2j
1  AABOUD 2019AP based on 36.1 fb${}^{-1}$ of data. The upper limit corresponds to 5.1 times the NLO SM cross section.
2  AABOUD 2019AP limit from data combined with AABOUD 2018CE. The upper limit corresponds to 5.3 times the NLO SM cross section. Also a limit on the four-top-quark contact interaction of $\vert \mathit C_{4t}\vert /\Lambda {}^{2}$ $<$ 1.9 TeV${}^{-2}$ (95$\%$ CL) is obtained in an EFT model.
3  SIRUNYAN 2019CN based on 35.8 fb${}^{-1}$ of data, combined with SIRUNYAN 2018BU. The results are also interpreted in the effective field theory framework.
4  SIRUNYAN 2019CN based on 35.8 fb${}^{-1}$ of data. A multivariate analysis using global event and jet propoerties is performed to discriminate from ${{\mathit t}}{{\overline{\mathit t}}}$ background.
5  AABOUD 2018CE based on 36.1 fb${}^{-1}$ of proton-proton data taken at $\sqrt {s }$ = 13 TeV. Events including a same-sign lepton pair are used. The result is consistent with the NLO SM cross section of 9.2 fb.
6  SIRUNYAN 2018BU based on 35.9 fb${}^{-1}$ of proton-proton data taken at $\sqrt {s }$ = 13 TeV. Yields from signal regions and control regions defined based on ${{\mathit N}_{{jets}}}$, ${{\mathit N}_{{b}}}$ and ${{\mathit N}_{{l}}}$ are combined in a maximum-likelihood fit. The result is in agreement with the NLO SM prediction $9.2$ ${}^{+2.9}_{-2.4}$ fb. The measurement constrains the top quark Yukawa coupling strength parameter to be $\vert \mathit Y_{t}/\mathit Y{}^{SM}_{t}\vert$ $<$ 2.1 (95$\%$ CL).
7  SIRUNYAN 2017AB based on 2.6 fb${}^{-1}$ of data. A multivariate analysis is used to discriminate between ${{\mathit t}}{{\overline{\mathit t}}}{{\mathit t}}{{\overline{\mathit t}}}$ signal and ${{\mathit t}}{{\overline{\mathit t}}}$ background. A combination with a previous search (CMS, KHACHATRYAN 2016BJ) in the same-sign dilepton channel gives an upper limit of 69 fb (95$\%$ CL), corresponding to 7.4$\cdot{}$(SM prediction).
8  SIRUNYAN 2017S based on 35.9 fb${}^{-1}$. The limit is in agreement with the NLO SM prediction $9.2$ ${}^{+2.9}_{-2.4}$ fb. Superseded by SIRUNYAN 2018BU. The signal events are also used to constrain various new physics models.
References:
 AABOUD 2019AP
PR D99 052009 Search for four-top-quark production in the single-lepton and opposite-sign dilepton final states in pp collisions at $\sqrt{s}$ = 13 TeV with the ATLAS detector
 SIRUNYAN 2019CN
JHEP 1911 082 Search for the production of four top quarks in the single-lepton and opposite-sign dilepton final states in proton-proton collisions at $\sqrt{s}$ = 13 TeV
 AABOUD 2018CE
JHEP 1812 039 Search for new phenomena in events with same-charge leptons and $b$-jets in $pp$ collisions at $\sqrt{s}= 13$ TeV with the ATLAS detector
 SIRUNYAN 2018BU
EPJ C78 140 Search for standard model production of four top quarks with same-sign and multilepton final states in proton?proton collisions at $\sqrt{s} = 13\,\text {TeV}$
 SIRUNYAN 2017S
EPJ C77 578 Search for Physics beyond the Standard Model in Events with Two Leptons of Same Sign, Missing Transverse Momentum, and Jets in Proton-Proton Collisions at $\sqrt {s }$ = 13 TeV
 SIRUNYAN 2017AB
PL B772 336 Search for Standard Model Production of Four Top Quarks in Proton-Proton Collisions at $\sqrt {s }$ = 13 TeV