4,084 research outputs found
catena-Poly[[(2,2′:6′,2′′-terpyridine-κ3 N,N′,N′′)zinc(II)]-μ-2,2′-oxydibenzoÂato-κ2 O:O′]
In the title compound, [Zn(C14H8O5)(C15H11N3)]n, both the ZnII ion and the oxydibenzoate ligand are located on a twofold rotation axis. The ZnII centre is coordinated by three N atoms from a chelating 2,2′:6′,2′′-terpyridine ligand and two O atoms from two 2,2′-oxydibenzoate ligands, forming a distorted trigonal-bipyramidal coordination environment. Further coordination via the 2,2′-oxydibenzoate anions forms a one-dimensional coordination polymer extending parallel to [010]. Aromatic π–π stacking interÂactions are observed between adjacent terpyridine ligands with a centroid–centroid distance of 3.568 (2) Å
Leptonic decays in the littlest model with T-parity
The littlest model with T-parity (called the model) predicts
the existence of the T-odd leptons, which can generate contributions to some
leptonic processes at the one-loop level. We calculate their contributions to
the leptonic decay processes , , and
Z\rightarro \nu\bar{\nu}. We find that the T-odd leptons can give significant
contributions to the branching ratios of these decay processes in most of the
parameter space. The experimental measurement values might generate constraints
on the free parameters of the model.Comment: 16 pages, 8 figures, minor corrections; final version published in
Phys.Rev.
Automatic Article Commenting: the Task and Dataset
Comments of online articles provide extended views and improve user
engagement. Automatically making comments thus become a valuable functionality
for online forums, intelligent chatbots, etc. This paper proposes the new task
of automatic article commenting, and introduces a large-scale Chinese dataset
with millions of real comments and a human-annotated subset characterizing the
comments' varying quality. Incorporating the human bias of comment quality, we
further develop automatic metrics that generalize a broad set of popular
reference-based metrics and exhibit greatly improved correlations with human
evaluations.Comment: ACL2018; with supplements; Dataset link available in the pape
Numerical and experimental investigation of nonlinear properties of rubber absorber in rail fastening
International audienceA nonlinear dynamic model of a rubber absorber in railway fastening systems is proposed, based on the superposition principle to simulate its nonlinear vibrational behavior. A dynamic experiment was carried out to obtain all model parameters. The accuracy of the model was supported by good agreement between measured and simulated results, and it should therefore be an effective mechanical tool for simulating and characterizing the nonlinear behavior of rubber absorbers in rail fastening systems at particular vibrational modes. Excitation frequency dependency and amplitude dependency of the nonlinear dynamic stiffness were also selected for further study. The results indicate that characteristics of the nonlinear dynamic stiffness are closely associated with both displacement amplitude and frequency, although frequency dependency is not as great as amplitude dependency
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
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
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