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.
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.
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.
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.
We provide an overview of the status of Monte-Carlo event generators for high-energy particle physics. Guided by the experimental needs and requirements, we highlight areas of active development, and ...opportunities for future improvements. Particular emphasis is given to physics models and algorithms that are employed across a variety of experiments. These common themes in event generator development lead to a more comprehensive understanding of physics at the highest energies and intensities, and allow models to be tested against a wealth of data that have been accumulated over the past decades. A cohesive approach to event generator development will allow these models to be further improved and systematic uncertainties to be reduced, directly contributing to future experimental success. Event generators are part of a much larger ecosystem of computational tools. They typically involve a number of unknown model parameters that must be tuned to experimental data, while maintaining the integrity of the underlying physics models. Making both these data, and the analyses with which they have been obtained accessible to future users is an essential aspect of open science and data preservation. It ensures the consistency of physics models across a variety of experiments.
We tested a newly described molecular memory system, CCR5 signaling, for its role in recovery after stroke and traumatic brain injury (TBI). CCR5 is uniquely expressed in cortical neurons after ...stroke. Post-stroke neuronal knockdown of CCR5 in pre-motor cortex leads to early recovery of motor control. Recovery is associated with preservation of dendritic spines, new patterns of cortical projections to contralateral pre-motor cortex, and upregulation of CREB and DLK signaling. Administration of a clinically utilized FDA-approved CCR5 antagonist, devised for HIV treatment, produces similar effects on motor recovery post stroke and cognitive decline post TBI. Finally, in a large clinical cohort of stroke patients, carriers for a naturally occurring loss-of-function mutation in CCR5 (CCR5-Δ32) exhibited greater recovery of neurological impairments and cognitive function. In summary, CCR5 is a translational target for neural repair in stroke and TBI and the first reported gene associated with enhanced recovery in human stroke.
Display omitted
•CCR5 is differentially upregulated in neurons after stroke•Knockdown of CCR5 induces motor recovery after stroke and improves cognition after TBI•Treatment with an FDA-approved drug, maraviroc induces recovery after stroke and TBI•Human carriers for CCR5delta32 have better outcomes after stroke
Genetic and small molecule-based perturbation of CCR5 promotes functional recovery from stroke and traumatic brain injury.
A bstract 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.
Tomato (Solanum lycopersicum L. 'Cauralina') plants were grown organically in a plastic tunnel, from 30 March to the beginning of August 2011. From mid-May, four treatments were applied: high water ...supply/high nitrogen (W+/N+), reduced water supply/high nitrogen (W-/N+), high water supply/low nitrogen (W+/N-) and low water supply/low nitrogen (W-/N-). Irrigation was triggered beginning on 20 May to keep water tension between 10-30 cbars in the W+ treatments, and 30-50 cbars in the W- treatments. In the N+ treatments, 10 kg N ha-1 × 4 was supplied, while no N was supplied during the cropping season in the N- treatments. Water supply was reduced by 23% at the end of the trial in the W- treatments, whereas the nitrate content of plants and maximal photosynthesis were not significantly modified in the N- treatments. By contrast, from mid-June, chlorophyll content was found to be lower in the N- treatments. Midday leaf water potential and stomatal conductance were lower only from the end of June in the W- treatments. Leaf net photosynthesis, respiration, yield, mean fruit mass, fruit taste and concentration in organic acids were not modified by the treatments. In the W+/N- treatment, fruit harvested on 4 August contained more reducing sugars (+ 13%) and vitamin C (+ 35%) than the W+/N+ fruit. There was also a 15% increase in vitamin C in the fruit of the W-/N- treatment when compared with W-/N+ fruit. Our observations suggest that it is possible to reduce irrigation and nitrogen supply in organic tomato crops without any negative effect on yield and quality.
Abstract We extract the top-quark mass value in the on-shell renormalization scheme from the comparison of theoretical predictions for pp → t t ¯ $$ t\overline{t} $$ + 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 1σ uncertainty, whereas some datasets related to t t ¯ $$ t\overline{t} $$ 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 ¯ $$ t\overline{t} $$ + X total and multi-differential cross sections from the LHC.
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