The possibilities of the combined recycling of wood and polyethylene terephthalate (PET) waste are examined. The mechanisms of the principal processes occurring in the production of the composite are ...described.
The performance of the missing transverse momentum (
E
T
miss
) reconstruction with the ATLAS detector is evaluated using data collected in proton–proton collisions at the LHC at a centre-of-mass ...energy of 13 TeV in 2015. To reconstruct
E
T
miss
, fully calibrated electrons, muons, photons, hadronically decaying
τ
-leptons
, and jets reconstructed from calorimeter energy deposits and charged-particle tracks are used. These are combined with the soft hadronic activity measured by reconstructed charged-particle tracks not associated with the hard objects. Possible double counting of contributions from reconstructed charged-particle tracks from the inner detector, energy deposits in the calorimeter, and reconstructed muons from the muon spectrometer is avoided by applying a signal ambiguity resolution procedure which rejects already used signals when combining the various
E
T
miss
contributions. The individual terms as well as the overall reconstructed
E
T
miss
are evaluated with various performance metrics for scale (linearity), resolution, and sensitivity to the data-taking conditions. The method developed to determine the systematic uncertainties of the
E
T
miss
scale and resolution is discussed. Results are shown based on the full 2015 data sample corresponding to an integrated luminosity of
3.2
fb
-
1
.
Higgs boson properties are studied in the four-lepton decay channel (where lepton = e, μ) 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 for H→ZZ∗ decay is measured to be 1.34±0.12 pb for a Higgs boson with absolute rapidity below 2.5, in good agreement with the Standard Model prediction of 1.33±0.08 pb. Cross-sections times branching ratio are measured for the main Higgs boson production modes in several exclusive phase-space regions. The measurements are interpreted in terms of coupling modifiers and of the tensor structure of Higgs boson interactions using an effective field theory approach. Exclusion limits are set on the CP-even and CP-odd ‘beyond the Standard Model’ couplings of the Higgs boson to vector bosons, gluons and top quarks.
A search for the supersymmetric partners of quarks and gluons (squarks and gluinos) in final states containing jets and missing transverse momentum, but no electrons or muons, is presented. The data ...used in this search were recorded by the ATLAS experiment in proton-proton collisions at a centre-of-mass energy of root s = 13 TeV during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb(-1). The results are interpreted in the context of various R-parity-conserving models where squarks and gluinos are produced in pairs or in association and a neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 2.30 TeV for a simplified model containing only a gluino and the lightest neutralino, assuming the latter is massless. For a simplified model involving the strong production of mass-degenerate first- and second-generation squarks, squark masses below 1.85 TeV are excluded if the lightest neutralino is massless. These limits extend substantially beyond the region of supersymmetric parameter space excluded previously by similar searches with the ATLAS detector.
A
bstract
A search for Higgs boson pair production in the
b
b
¯
b
b
¯
final state is carried out with up to 36.1 fb
−1
of LHC proton-proton collision data collected at
s
=
13
TeV with the ATLAS ...detector in 2015 and 2016. Three benchmark signals are studied: a spin-2 graviton decaying into a Higgs boson pair, a scalar resonance decaying into a Higgs boson pair, and Standard Model non-resonant Higgs boson pair production. Two analyses are carried out, each implementing a particular technique for the event reconstruction that targets Higgs bosons reconstructed as pairs of jets or single boosted jets. The resonance mass range covered is 260–3000 GeV. The analyses are statistically combined and upper limits on the production cross section of Higgs boson pairs times branching ratio to
b
b
¯
b
b
¯
are set in each model. No significant excess is observed; the largest deviation of data over prediction is found at a mass of 280 GeV, corresponding to 2.3 standard deviations globally. The observed 95% confidence level upper limit on the non-resonant production is 13 times the Standard Model prediction.
A multi-platform validation and analysis framework for public Monte Carlo simulation for high-energy particle collisions is discussed. The front-end of this framework uses the Python programming ...language, while the back-end is written in Java, which provides a multi-platform environment that can be run from a web browser and can easily be deployed at the grid sites. The analysis package includes all major software tools used in high-energy physics, such as Lorentz vectors, jet algorithms, histogram packages, graphic canvases, and tools for providing data access. This multi-platform software suite, designed to minimize OS-specific maintenance and deployment time, is used for online validation of Monte Carlo event samples through a web interface.
A
bstract
A search for the decay of the Standard Model Higgs boson into a
b
b
¯
pair when produced in association with a
W
or
Z
boson is performed with the ATLAS detector. The analysed data, ...corresponding to an integrated luminosity of 36.1 fb
−1
, were collected in proton-proton collisions in Run 2 of the Large Hadron Collider at a centre-of-mass energy of 13 TeV. Final states containing zero, one and two charged leptons (electrons or muons) are considered, targeting the decays
Z
→
νν
,
W
→
ℓν
and
Z
→
ℓℓ
. For a Higgs boson mass of 125 GeV, an excess of events over the expected background from other Standard Model processes is found with an observed significance of 3.5 standard deviations, compared to an expectation of 3.0 standard deviations. This excess provides evidence for the Higgs boson decay into b-quarks and for its production in association with a vector boson. The combination of this result with that of the Run 1 analysis yields a ratio of the measured signal events to the Standard Model expectation equal to 0.90 ± 0.18(stat.)
− 0.19
+ 0.21
(syst.). Assuming the Standard Model production cross-section, the results are consistent with the value of the Yukawa coupling to
b
-quarks in the Standard Model.
A search for neutral heavy resonances is performed in the
W
W
→
e
ν
μ
ν
decay channel using
pp
collision data corresponding to an integrated luminosity of
36.1
fb
-
1
, collected at a centre-of-mass ...energy of 13
TeV
by the ATLAS detector at the Large Hadron Collider. No evidence of such heavy resonances is found. In the search for production via the quark–antiquark annihilation or gluon–gluon fusion process, upper limits on
σ
X
×
B
(
X
→
W
W
)
as a function of the resonance mass are obtained in the mass range between 200
GeV
and up to 5
TeV
for various benchmark models: a Higgs-like scalar in different width scenarios, a two-Higgs-doublet model, a heavy vector triplet model, and a warped extra dimensions model. In the vector-boson fusion process, constraints are also obtained on these resonances, as well as on a Higgs boson in the Georgi–Machacek model and a heavy tensor particle coupling only to gauge bosons.
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