In this paper, we introduce the Flux Coupling Finder (FCF) framework for elucidating the topological and flux connectivity features of genome-scale metabolic networks. The framework is demonstrated ...on genome-scale metabolic reconstructions of Helicobacter pylori, Escherichia coli, and Saccharomyces cerevisiae. The analysis allows one to determine whether any two metabolic fluxes, v(1) and v(2), are (1) directionally coupled, if a non-zero flux for v(1) implies a non-zero flux for v(2) but not necessarily the reverse; (2) partially coupled, if a non-zero flux for v(1) implies a non-zero, though variable, flux for v(2) and vice versa; or (3) fully coupled, if a non-zero flux for v(1) implies not only a non-zero but also a fixed flux for v(2) and vice versa. Flux coupling analysis also enables the global identification of blocked reactions, which are all reactions incapable of carrying flux under a certain condition; equivalent knockouts, defined as the set of all possible reactions whose deletion forces the flux through a particular reaction to zero; and sets of affected reactions denoting all reactions whose fluxes are forced to zero if a particular reaction is deleted. The FCF approach thus provides a novel and versatile tool for aiding metabolic reconstructions and guiding genetic manipulations.
The luminosity determination for the ATLAS detector at the LHC during Run 2 is presented, with
pp
collisions at a centre-of-mass energy
s
=
13
TeV. The absolute luminosity scale is determined using ...van der Meer beam separation scans during dedicated running periods in each year, and extrapolated to the physics data-taking regime using complementary measurements from several luminosity-sensitive detectors. The total uncertainties in the integrated luminosity for each individual year of data-taking range from 0.9% to 1.1%, and are partially correlated between years. After standard data-quality selections, the full Run 2
pp
data sample corresponds to an integrated luminosity of
140.1
±
1.2
fb
-
1
, i.e. an uncertainty of 0.83%. A dedicated sample of low-pileup data recorded in 2017–2018 for precision Standard Model physics measurements is analysed separately, and has an integrated luminosity of
338.1
±
3.1
pb
-
1
.
A
bstract
A search for the electroweak production of pairs of charged sleptons or charginos decaying into two-lepton final states with missing transverse momentum is presented. Two simplified models ...of
R
-parity-conserving supersymmetry are considered: direct pair-production of sleptons
ℓ
~
ℓ
~
, with each decaying into a charged lepton and a
χ
~
1
0
neutralino, and direct pair-production of the lightest charginos
χ
~
1
±
χ
~
1
∓
, with each decaying into a
W
-boson and a
χ
~
1
0
. The lightest neutralino
χ
~
1
0
is assumed to be the lightest supersymmetric particle (LSP). The analyses target the experimentally challenging mass regions where
m
ℓ
~
−
m
χ
~
1
0
and
m
χ
~
1
±
−
m
χ
~
1
0
are close to the
W
-boson mass (‘moderately compressed’ regions). The search uses 139 fb
−
1
of
s
= 13 TeV proton-proton collisions recorded by the ATLAS detector at the Large Hadron Collider. No significant excesses over the expected background are observed. Exclusion limits on the simplified models under study are reported in the
ℓ
~
χ
~
1
0
and
χ
~
1
±
χ
~
1
0
mass planes at 95% confidence level (CL). Sleptons with masses up to 150 GeV are excluded at 95% CL for the case of a mass-splitting between sleptons and the LSP of 50 GeV. Chargino masses up to 140 GeV are excluded at 95% CL for the case of a mass-splitting between the chargino and the LSP down to about 100 GeV.
This paper presents an analysis at next-to-next-to-leading order in the theory of quantum chromodynamics for the determination of a new set of proton parton distribution functions using diverse ...measurements in
pp
collisions at
s
=
7
, 8 and 13 TeV, performed by the ATLAS experiment at the Large Hadron Collider, together with deep inelastic scattering data from
ep
collisions at the HERA collider. The ATLAS data sets considered are differential cross-section measurements of inclusive
W
±
and
Z
/
γ
∗
boson production,
W
±
and
Z
boson production in association with jets,
t
t
¯
production, inclusive jet production and direct photon production. In the analysis, particular attention is paid to the correlation of systematic uncertainties within and between the various ATLAS data sets and to the impact of model, theoretical and parameterisation uncertainties. The resulting set of parton distribution functions is called ATLASpdf21.
A
bstract
A measurement of inclusive and differential fiducial cross-sections for the production of the Higgs boson decaying into two photons is performed using 139 fb
−
1
of proton-proton collision ...data recorded at
s
= 13 TeV by the ATLAS experiment at the Large Hadron Collider. The inclusive cross-section times branching ratio, in a fiducial region closely matching the experimental selection, is measured to be 67
±
6 fb, which is in agreement with the state-of-the-art Standard Model prediction of 64
±
4 fb. Extrapolating this result to the full phase space and correcting for the branching ratio, the total cross-section for Higgs boson production is estimated to be 58
±
6 pb. In addition, the cross-sections in four fiducial regions sensitive to various Higgs boson production modes and differential cross-sections as a function of either one or two of several observables are measured. All the measurements are found to be in agreement with the Standard Model predictions. The measured transverse momentum distribution of the Higgs boson is used as an indirect probe of the Yukawa coupling of the Higgs boson to the bottom and charm quarks. In addition, five differential cross-section measurements are used to constrain anomalous Higgs boson couplings to vector bosons in the Standard Model effective field theory framework.
A
bstract
Differential and double-differential distributions of kinematic variables of leptons from decays of top-quark pairs (
t
t
¯
) are measured using the full LHC Run 2 data sample collected ...with the ATLAS detector. The data were collected at a
pp
collision energy of
s
= 13 TeV and correspond to an integrated luminosity of 140 fb
−
1
. The measurements use events containing an oppositely charged
eμ
pair and
b
-tagged jets. The results are compared with predictions from several Monte Carlo generators. While no prediction is found to be consistent with all distributions, a better agreement with measurements of the lepton
p
T
distributions is obtained by reweighting the
t
t
¯
sample so as to reproduce the top-quark
p
T
distribution from an NNLO calculation. The inclusive top-quark pair production cross-section is measured as well, both in a fiducial region and in the full phase-space. The total inclusive cross-section is found to be
σ
t
t
¯
=
829
±
1
stat
±
13
syst
±
8
lumi
±
2
beam
pb
,
where the uncertainties are due to statistics, systematic effects, the integrated luminosity and the beam energy. This is in excellent agreement with the theoretical expectation.
PDF
