2,275 research outputs found
Identifying vital edges in Chinese air route network via memetic algorithm
Due to its rapid development in the past decade, air transportation system
has attracted considerable research attention from diverse communities. While
most of the previous studies focused on airline networks, here we
systematically explore the robustness of the Chinese air route network, and
identify the vital edges which form the backbone of Chinese air transportation
system. Specifically, we employ a memetic algorithm to minimize the network
robustness after removing certain edges hence the solution of this model is the
set of vital edges. Counterintuitively, our results show that the most vital
edges are not necessarily the edges of highest topological importance, for
which we provide an extensive explanation from the microscope of view. Our
findings also offer new insights to understanding and optimizing other
real-world network systems
Study of the quasi-two-body decays B^{0}_{s} \rightarrow \psi(3770)(\psi(3686))\pi^+\pi^- with perturbative QCD approach
In this note, we study the contributions from the S-wave resonances,
f_{0}(980) and f_{0}(1500), to the B^{0}_{s}\rightarrow \psi(3770)\pi^
{+}\pi^{-} decay by introducing the S-wave \pi\pi distribution amplitudes
within the framework of the perturbative QCD approach. Both resonant and
nonresonant contributions are contained in the scalar form factor in the S-wave
distribution amplitude \Phi^S_{\pi\pi}. Since the vector charmonium meson
\psi(3770) is a S-D wave mixed state, we calculated the branching ratios of
S-wave and D-wave respectively, and the results indicate that f_{0}(980) is the
main contribution of the considered decay, and the branching ratio of the
\psi(2S) mode is in good agreement with the experimental data. We also take the
S-D mixed effect into the B^{0}_{s}\rightarrow \psi(3686)\pi^ {+}\pi^{-} decay.
Our calculations show that the branching ratio of B^{0}_{s}\rightarrow
\psi(3770)(\psi(3686))\pi^ {+}\pi^{-} can be at the order of 10^{-5}, which can
be tested by the running LHC-b experiments.Comment: 10 pages, 3 figure
Van der Waals-like phase transition from holographic entanglement entropy in Lorentz breaking massive gravity
In this paper, phase transition of AdS black holes in lorentz breaking
massive gravity has been studied in the framework of holography. We find that
there is a first order phase transition(FPT) and second order phase
transition(SPT) both in Bekenstein-Hawking entropy(BHE)-temperature plane and
holographic entanglement entropy(HEE)-temperature plane. Furthermore, for the
FPT, the equal area law is checked and for the SPT, the critical exponent of
the heat capacity is also computed. Our results confirm that the phase
structure of HEE is similar to that of BHE in lorentz breaking massive gravity,
which implies that HEE and BHE have some potential underlying relationship.Comment: 10 pages, 10 figure
- …