Combination of inclusive top-quark pair production cross-section measurements using ATLAS and CMS data at √s = 7 and 8 TeV
Abstract A combination of measurements of the inclusive top-quark pair production cross-section performed by ATLAS and CMS in proton–proton collisions at centre-of-mass energies of 7 and 8 TeV at the LHC is presented. The cross-sections are obtained using top-qu...
| Main Authors: | , , , , , , , , , , , , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
Springer Berlin Heidelberg
2023
|
| Online Access: | https://hdl.handle.net/1721.1/152105 |
| Summary: | Abstract
A combination of measurements of the inclusive top-quark pair production cross-section performed by ATLAS and CMS in proton–proton collisions at centre-of-mass energies of 7 and 8 TeV at the LHC is presented. The cross-sections are obtained using top-quark pair decays with an opposite-charge electron–muon pair in the final state and with data corresponding to an integrated luminosity of about 5 fb−1 at
s
$$ \sqrt{s} $$
= 7 TeV and about 20 fb−1 at
s
$$ \sqrt{s} $$
= 8 TeV for each experiment. The combined cross-sections are determined to be 178.5 ± 4.7 pb at
s
$$ \sqrt{s} $$
= 7 TeV and
243.3
−
5.9
+
6.0
$$ {243.3}_{-5.9}^{+6.0} $$
pb at
s
$$ \sqrt{s} $$
= 8 TeV with a correlation of 0.41, using a reference top-quark mass value of 172.5 GeV. The ratio of the combined cross-sections is determined to be R8/7 = 1.363 ± 0.032. The combined measured cross-sections and their ratio agree well with theory calculations using several parton distribution function (PDF) sets. The values of the top-quark pole mass (with the strong coupling fixed at 0.118) and the strong coupling (with the top-quark pole mass fixed at 172.5 GeV) are extracted from the combined results by fitting a next-to-next-to-leading-order plus next-to-next-to-leading-log QCD prediction to the measurements. Using a version of the NNPDF3.1 PDF set containing no top-quark measurements, the results obtained are
m
t
pole
=
173.4
−
2.0
+
1.8
$$ {m}_t^{\textrm{pole}}={173.4}_{-2.0}^{+1.8} $$
GeV and
α
s
m
Z
=
0.1170
−
0.0018
+
0.0021
$$ {\alpha}_{\textrm{s}}\left({m}_Z\right)={0.1170}_{-0.0018}^{+0.0021} $$
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