Detecting interactions between dark matter and photons at high energy e+e−e^+e^- colliders

We investigate the sensitivity to the effective operators describing interactions between dark matter particles and photons at future high energy $e^+e^-$ colliders via the \gamma+ \slashed{E} channel. Such operators could be useful to interpret the potential gamma-ray line signature observed by the Fermi-LAT. We find that these operators can be further tested at $e^+ e^-$ colliders by using either unpolarized or polarized beams. We also derive a general unitarity condition for $2 \to n$ processes and apply it to the dark matter production process $e^+e^-\to\chi\chi\gamma$.Comment: 13 pages, 8 figure

Ripple Algorithm to Evaluate the Importance of Network Nodes

Inthis paper raise the ripples algorithm to evaluate the importance of network node was proposed, its principle is based onthe direct influence of adjacent nodes, and affect farther nodes indirectlyby closer ones just like the ripples on the water. Then we defined two judgments,the discriminationof node importance and the accuracy of key node selecting, to verify its efficiency. The greater degree of discriminationand higher accuracy means better efficiency of algorithm. At last we performed experiment on ARPA network, to compare the efficiency of different algorithms, closeness centricity, node deletion, node contraction method, algorithm raised by Zhou Xuan etc. and ripple method. Results show that ripple algorithm is better than the other measures in the discrimination of node importance and the accuracy of key node selecting