The classification of log Enriques surfaces of rank 18

Log Enriques surface is a generalization of K3 and Enriques surface. We will classify all the rational log Enriques surfaces of rank 18 by giving concrete models for the realizable types of these surfaces.Comment: 31 pages, 2 figures, to be published in Journal of the Korean Mathematical Societ

Deflected Anomaly Mediated SUSY Breaking Scenario With General Messenger-Matter Interactions

We propose to introduce general messenger-matter interactions in the deflected anomaly mediated SUSY breaking scenario. The most general form for the resulting soft parameters are derived. New interference terms between the GMSB type and AMSB type contributions are the unique feature of this scenario. Messenger-matter interactions involving sleptons can be used to solve the tachyonic slepton problem and naturally lead to positive slepton masses regardless of the sign of deflection parameter. Besides, due to the new contributions, large $|A_t|$ that will not trigger color-breaking stop VEV are also possible in this scenario, thus can easily give the 125 GeV higgs which was discovered by LHC. This type of deflected AMSB scenario need very few messenger species, thus can avoid possible non-perturbative gauge couplings below the GUT scale ( or Landau pole below the Planck scale ).Comment: Minor changes. 13 pages, no figures. Version accepted by Phys. Lett.

The pole structure of low energy πN\pi N scattering amplitudes

This report presents an investigation of the pion-nucleon elastic scattering in low energy region using a production representation of the partial wave $S$ matrix. The phase shifts are separated into contributions from poles and branch cuts, where the left-hand cut term can be evaluated by tree-level covariant baryon chiral perturbation theory. A comparison between the sum of known contributions and the data in $S$- and $P$- wave channels is made. It is found that the known components in $S_{11}$ and $P_{11}$ channels are far from enough to saturate the corresponding experimental data, indicating the existence of low-lying hidden poles. The positions of those hidden poles are figured out and the physics behind them are explored.Comment: 5 pages. Conference proceeding of 15th International Workshop on Meson Physics, Cracow, Poland, 7th-12th June 201