Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
97
result(s) for
"Mazzitelli, J"
Sort by:
Higgs boson pair production at NNLO with top quark mass effects
A
bstract
We consider QCD radiative corrections to Higgs boson pair production through gluon fusion in proton collisions. We combine the exact next-to-leading order (NLO) contribution, which features two-loop virtual amplitudes with the full dependence on the top quark mass
M
t
, with the next-to-next-to-leading order (NNLO) corrections computed in the large-
M
t
approximation. The latter are improved with different reweighting techniques in order to account for finite-
M
t
effects beyond NLO. Our reference NNLO result is obtained by combining one-loop double-real corrections with full
M
t
dependence with suitably reweighted real-virtual and double-virtual contributions evaluated in the large-
M
t
approximation. We present predictions for inclusive cross sections in
pp
collisions at
s
= 13, 14, 27 and 100 TeV and we discuss their uncertainties due to missing
M
t
effects. Our approximated NNLO corrections increase the NLO result by an amount ranging from +12% at
s
=
13
TeV to +7% at
s
=
100
TeV, and the residual uncertainty of the inclusive cross section from missing
M
t
effects is estimated to be at the few percent level. Our calculation is fully differential in the Higgs boson pair and the associated jet activity: we also present predictions for various differential distributions at
s
=
14
and 100 TeV, and discuss the size of the missing
M
t
effects, which can be larger, especially in the tails of certain observables. Our results represent the most advanced perturbative prediction available to date for this process.
Journal Article
CREB controls cortical circuit plasticity and functional recovery after stroke
Treatments that stimulate neuronal excitability enhance motor performance after stroke. cAMP-response-element binding protein (CREB) is a transcription factor that plays a key role in neuronal excitability. Increasing the levels of CREB with a viral vector in a small pool of motor neurons enhances motor recovery after stroke, while blocking CREB signaling prevents stroke recovery. Silencing CREB-transfected neurons in the peri-infarct region with the hM4Di-DREADD blocks motor recovery. Reversing this inhibition allows recovery to continue, demonstrating that by manipulating the activity of CREB-transfected neurons it is possible to turn off and on stroke recovery. CREB transfection enhances remapping of injured somatosensory and motor circuits, and induces the formation of new connections within these circuits. CREB is a central molecular node in the circuit responses after stroke that lead to recovery from motor deficits.
Increasing excitability in the peri-infarct area enhances motor recovery after stroke. Here the authors show that expressing CREB, a transcription factor known for its role in synaptic plasticity, or increasing activity of CREB-expressing cells near the stroke site improves recovery in an effect that is strong enough that it can be used to turn on and off motor recovery after stroke.
Journal Article
Top-quark pole mass extraction at NNLO accuracy, from total, single- and double-differential cross sections for tt¯ + X production at the LHC
A
bstract
We extract the top-quark mass value in the on-shell renormalization scheme from the comparison of theoretical predictions for
pp
→
t
t
¯
+
X
at next-to-next-to-leading order (NNLO) QCD accuracy with experimental data collected by the ATLAS and CMS collaborations for absolute total, normalized single-differential and double-differential cross-sections during Run 1, Run 2 and the ongoing Run 3 at the Large Hadron Collider (LHC). For the theory computations of heavy-quark pair-production we use the MATRIX framework, interfaced to PineAPPL for the generation of grids of theory predictions, which can be efficiently used a-posteriori during the fit, performed within xFitter. We take several state-of-the-art parton distribution functions (PDFs) as input for the fit and evaluate their associated uncertainties, as well as the uncertainties arising from renormalization and factorization scale variation. Fit uncertainties related to the datasets are also part of the extracted uncertainty of the top-quark mass and turn out to be of similar size as the combined scale and PDF uncertainty. Fit results from different PDF sets agree among each other within 1
σ
uncertainty, whereas some datasets related to
t
t
¯
decay in different channels (dileptonic vs. semileptonic) point towards top-quark mass values in slight tension among each other, although still compatible within 2
.
5
σ
accuracy. Our results are compatible with the PDG 2022 top-quark pole-mass value. Our work opens the road towards more complex simultaneous NNLO fits of PDFs, the strong coupling
α
s
(
M
Z
) and the top-quark mass, using the currently most precise experimental data on
t
t
¯
+
X
total and multi-differential cross sections from the LHC.
Journal Article
Approximate N3LO Higgs-boson production cross section using physical-kernel constraints
A
bstract
The single-logarithmic enhancement of the physical kernel for Higgs production by gluon-gluon fusion in the heavy top-quark limit is employed to derive the leading so far unknown contributions, ln
5, 4, 3
(1−
z
), to the N
3
LO coefficient function in the threshold expansion. Also using knowledge from Higgs-exchange DIS to estimate the remaining terms not vanishing for
z
=
m
H
2
/
ŝ
→ 1, these results are combined with the recently completed soft + virtual contributions to provide an uncertainty band for the complete N
3
LO correction. For the 2008 MSTW parton distributions these N
3
LO contributions increase the cross section at 14 TeV by (10 ±2)% and (3 ±2
.
5)% for the standard choices
μ
R
=
m
H
and
μ
R
=
m
H
/
2 of the renormalization scale. The remaining uncertainty arising from the hard-scattering cross sections can be quantified as no more than 5%, which is smaller than that due to the strong coupling and the parton distributions.
Journal Article
Top-quark pole mass extraction at NNLO accuracy, from total, single- and double-differential cross sections for$$ t\\overline{t} $$+ X production at the LHC
We extract the top-quark mass value in the on-shell renormalization scheme from the comparison of theoretical predictions for pp →$$ t\\overline{t} $$t t ¯ + X at next-to-next-to-leading order (NNLO) QCD accuracy with experimental data collected by the ATLAS and CMS collaborations for absolute total, normalized single-differential and double-differential cross-sections during Run 1, Run 2 and the ongoing Run 3 at the Large Hadron Collider (LHC). For the theory computations of heavy-quark pair-production we use the MATRIX framework, interfaced to PineAPPL for the generation of grids of theory predictions, which can be efficiently used a-posteriori during the fit, performed within xFitter. We take several state-of-the-art parton distribution functions (PDFs) as input for the fit and evaluate their associated uncertainties, as well as the uncertainties arising from renormalization and factorization scale variation. Fit uncertainties related to the datasets are also part of the extracted uncertainty of the top-quark mass and turn out to be of similar size as the combined scale and PDF uncertainty. Fit results from different PDF sets agree among each other within 1 σ uncertainty, whereas some datasets related to$$ t\\overline{t} $$t t ¯ decay in different channels (dileptonic vs. semileptonic) point towards top-quark mass values in slight tension among each other, although still compatible within 2 . 5 σ accuracy. Our results are compatible with the PDG 2022 top-quark pole-mass value. Our work opens the road towards more complex simultaneous NNLO fits of PDFs, the strong coupling α s ( M Z ) and the top-quark mass, using the currently most precise experimental data on$$ t\\overline{t} $$t t ¯ + X total and multi-differential cross sections from the LHC.
Journal Article
Top-quark pole mass extraction at NNLO accuracy, from total, single- and double-differential cross sections for t t ¯ tt̅ + X production at the LHC
Abstract We extract the top-quark mass value in the on-shell renormalization scheme from the comparison of theoretical predictions for pp → t t ¯ tt̅ + X at next-to-next-to-leading order (NNLO) QCD accuracy with experimental data collected by the ATLAS and CMS collaborations for absolute total, normalized single-differential and double-differential cross-sections during Run 1, Run 2 and the ongoing Run 3 at the Large Hadron Collider (LHC). For the theory computations of heavy-quark pair-production we use the MATRIX framework, interfaced to PineAPPL for the generation of grids of theory predictions, which can be efficiently used a-posteriori during the fit, performed within xFitter. We take several state-of-the-art parton distribution functions (PDFs) as input for the fit and evaluate their associated uncertainties, as well as the uncertainties arising from renormalization and factorization scale variation. Fit uncertainties related to the datasets are also part of the extracted uncertainty of the top-quark mass and turn out to be of similar size as the combined scale and PDF uncertainty. Fit results from different PDF sets agree among each other within 1σ uncertainty, whereas some datasets related to t t ¯ tt̅ decay in different channels (dileptonic vs. semileptonic) point towards top-quark mass values in slight tension among each other, although still compatible within 2.5 σ accuracy. Our results are compatible with the PDG 2022 top-quark pole-mass value. Our work opens the road towards more complex simultaneous NNLO fits of PDFs, the strong coupling α s (M Z ) and the top-quark mass, using the currently most precise experimental data on t t ¯ tt̅ + X total and multi-differential cross sections from the LHC.
Journal Article
Approximate N^sup 3^LO Higgs-boson production cross section using physical-kernel constraints
Abstract The single-logarithmic enhancement of the physical kernel for Higgs production by gluon-gluon fusion in the heavy top-quark limit is employed to derive the leading so far unknown contributions, ln ^sup 5, 4, 3^(1-z), to the N^sup 3^LO coefficient function in the threshold expansion. Also using knowledge from Higgs-exchange DIS to estimate the remaining terms not vanishing for z=m ^sub H^^sup 2^/[arrow right]1, these results are combined with the recently completed soft + virtual contributions to provide an uncertainty band for the complete N^sup 3^LO correction. For the 2008 MSTW parton distributions these N^sup 3^LO contributions increase the cross section at 14 TeV by (10 ±2)% and (3 ±2.5)% for the standard choices [mu] ^sub R^ = m ^sub H^ and [mu] ^sub R^ = m ^sub H^ /2 of the renormalization scale. The remaining uncertainty arising from the hard-scattering cross sections can be quantified as no more than 5%, which is smaller than that due to the strong coupling and the parton distributions.
Journal Article
Top-quark pole mass extraction at NNLO accuracy
We describe our recent NNLO QCD extraction of the top-quark pole mass from fits to experimental data on total inclusive and normalized (multi)-differential cross sections for \\(t\\bar{t} + X\\) hadroproduction, using as input various modern PDF + \\(\\alpha_s(M_Z)\\) sets. We find top-quark mass values compatible among each other and with the PDG 2024 preferred value.
Paper
Top-quark pole mass extraction at NNLO accuracy, from total, single- and double-differential cross sections for \\(t\\bar{t}+X\\) production at the LHC
We extract the top-quark mass value in the on-shell renormalization scheme from the comparison of theoretical predictions for \\(pp \\rightarrow t\\bar{t} + X\\) at next-to-next-to-leading order (NNLO) QCD accuracy with experimental data collected by the ATLAS and CMS collaborations for absolute total, normalized single-differential and double-differential cross-sections during Run 1, Run 2 and the ongoing Run 3 at the Large Hadron Collider (LHC). For the theory computations of heavy-quark pair-production we use the MATRIX framework, interfaced to PineAPPL for the generation of grids of theory predictions, which can be efficiently used a-posteriori during the fit, performed within xFitter. We take several state-of-the-art parton distribution functions (PDFs) as input for the fit and evaluate their associated uncertainties, as well as the uncertainties arising from renormalization and factorization scale variation. Fit uncertainties related to the datasets are also part of the extracted uncertainty of the top-quark mass and turn out to be of similar size as the combined scale and PDF uncertainty. Fit results from different PDF sets agree among each other within 1\\(\\sigma\\) uncertainty, whereas some datasets related to \\(t\\bar{t}\\) decay in different channels (dileptonic vs. semileptonic) point towards top-quark mass values in slight tension among each other, although still compatible within \\(2.5 \\sigma\\) accuracy. Our results are compatible with the PDG 2022 top-quark pole-mass value. Our work opens the road towards more complex simultaneous NNLO fits of PDFs, the strong coupling \\(\\alpha_s(M_Z)\\) and the top-quark mass, using the currently most precise experimental data on \\(t\\bar{t} + X\\) total and multi-differential cross-sections from the LHC.
Paper