5,935 research outputs found
Could be a molecular state?
We investigate whether the newly observed narrow resonance can
be described as a molecular state with quantum numbers
. Using QCD sum rules, we consider contributions up to dimension
six in the operator product expansion and work at leading order of
. The mass obtained for this state is (4.05\pm 0.28) \mbox{GeV}.
It is concluded that molecular state is a possible candidate
for .Comment: 7 pages, 4 figures.Published in Eur.Phys.J. C73 (2013) 2661. arXiv
admin note: text overlap with arXiv:1304.185
Higher order light-cone distribution amplitudes of the Lambda baryon
The improved light-cone distribution amplitudes (LCDAs) of the
baryon are examined on the basis of the QCD conformal partial wave expansion
approach. The calculations are carried out to the next-to-leading order of
conformal spin accuracy with consideration of twist 6. The next leading order
conformal expansion coefficients are related to the nonperturbative parameters
defined by the local three quark operator matrix elements with different
Lorentz structures with a covariant derivative. The nonperturbative parameters
are determined with the QCD sum rule method. The explicit expressions of the
LCDAs are provided as the main results.Comment: 17pages,10figures. arXiv admin note: text overlap with
arXiv:1311.596
Cascading failures in coupled networks with both inner-dependency and inter-dependency links
We study the percolation in coupled networks with both inner-dependency and
inter-dependency links, where the inner- and inter-dependency links represent
the dependencies between nodes in the same or different networks, respectively.
We find that when most of dependency links are inner- or inter-ones, the
coupled networks system is fragile and makes a discontinuous percolation
transition. However, when the numbers of two types of dependency links are
close to each other, the system is robust and makes a continuous percolation
transition. This indicates that the high density of dependency links could not
always lead to a discontinuous percolation transition as the previous studies.
More interestingly, although the robustness of the system can be optimized by
adjusting the ratio of the two types of dependency links, there exists a
critical average degree of the networks for coupled random networks, below
which the crossover of the two types of percolation transitions disappears, and
the system will always demonstrate a discontinuous percolation transition. We
also develop an approach to analyze this model, which is agreement with the
simulation results well.Comment: 9 pages, 4 figure
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