2,082 research outputs found
Transverse momentum resummation for color sextet and antitriplet scalar production at the LHC
We study the factorization and resummation of the transverse momentum
spectrum of the color sextet and antitriplet scalars produced at the LHC based
on soft-collinear effective theory. Compared to Z boson and Higgs production, a
soft function is required to account for the soft gluon emission from the
final-state colored scalar. The soft function is calculated at the
next-to-leading order, and the resummation is performed at the approximate
next-to-next-to-leading logarithmic accuracy. The non-perturbative effects and
PDF uncertainties are also discussed.Comment: 20 pages, 7 figure
Transverse-Momentum Resummation for Gauge Boson Pair Production at the Hadron Collider
We perform the transverse-momentum resummation for , , and
pair productions at the next-to-next-to-leading logarithmic accuracy
using soft-collinear effective theory for and
at the LHC, respectively. Especially, this is the
first calculation of transverse-momentum resummation. We also
include the non-perturbative effects and discussions on the PDF uncertainties.
Comparing with the next-to-leading logarithmic results, the
next-to-next-to-leading logarithmic resummation can reduce the dependence of
the transverse-momentum distribution on the factorization scales significantly.
Finally, we find that our numerical results are consistent with data measured
by CMS collaboration for the production, which have been only reported by
the LHC experiments for the unfolded transverse-momentum distribution of the
gauge boson pair production so far, within theoretical and experimental
uncertainties.Comment: 22 pages, 6 figures, re-versio
Structural dynamic response analysis on structure under tsunami bore impact
The forefront of the tsunami bore has extremely strong turbulent intensity, vorticity, and impact force. It generates tremendous impact effect on the coastal structures, which is the direct reason of the damage and destruction of the structures. On the basis of the computational fluid dynamic theory, this paper applied fluid volume method to capture the free surface motion of the tsunami waves and developed a 3D wave numerical model of an experiment of dam-break tsunami bore impact on a structure. The effectiveness of the model was also validated. The model was then applied to numerically analyze the dynamic impact effect of a tsunami bore on the structure of a full-scale reinforced concrete frame. It resolved the dynamic impact force of the tsunami bore on the structure and their interaction process. This study also employed finite element analysis to compare the static and dynamic response of the frame structure under the impact effect of the tsunami bore. The structural vibration characteristic and dynamic magnification factor of the structure under tsunami bore impact are confirmed, which could provide a reference for the design of anti-tsunami buildings
Analytic result for the top-quark width at next-to-next-to-leading order in QCD
We present the first full analytic results of next-to-next-to-leading order
(NNLO) QCD corrections to the top-quark decay width by
calculating the imaginary part of three-loop top-quark self-energy diagrams.
The results are all expressed in terms of harmonic polylogarithms and valid in
the whole region . The expansions in the and
limits coincide with previous studies. Our results can also be
taken as the exact prediction for the lepton invariant mass spectrum in
semileptonic decays. We also analytically compute the decay width
including the off-shell boson effect up to NNLO in QCD for the first time.
Combining these contributions with electroweak corrections and the finite
-quark mass effect, we determine the most precise top-quark width to be
1.331 GeV for GeV. The total theoretical uncertainties including
those from renormalization scale choice, top-quark renormalization scheme,
input parameters and missing higher-order corrections are scrutinized and found
to be less than .Comment: 8 pages, 3 figure
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