Determining the Mass for a Light Gravitino

Gauge mediated supersymmetry breaking scenarios with an ultra-light gravitino of mass m_{3/2}=1-10 eV are very interesting, since there is no cosmological gravitino problem. We propose a new experimental determination of the gravitino mass for such an ultra-light gravitino, by measuring a branching ratio of two decay modes of sleptons.Comment: 9 pages, 12 figure

Long-Lived Unstable Superparticles at the LHC

In various models of supersymmetry (SUSY), the lightest superparticle in the minimal SUSY standard model sector, which we call MSSM-LSP, becomes unstable. Then, we may observe the decay of the MSSM-LSP in the detector at the LHC experiment. We show that the discovery of such a decay process (and the determination of the lifetime of the MSSM-LSP) may be possible at the LHC even if the decay length of the MSSM-LSP is much longer than the size of the detector; sizable number of the MSSM-LSPs decay inside the detector if the lifetime is shorter than 0.01-1 millisec. We also discuss the implications of the study of the MSSM-LSP decay for several well-motivated SUSY models.Comment: 13 pages, 4 figure

Dense Communication and R&D in Knowledge-based Industrial Clusters: Comparative Study of Small & Medium-sized Firms in Korea and China

This paper presents analyses of the effects of dense communication of industry-academia-government cooperation on enhancement and reduction of in-house R&D activities using survey data of the Seoul Digital Industrial Complex, Daedeok Valley, and Zhongguancun Science Park. Our results show that older firms, presumably with more-experienced personnel, take more advantage of R&D cooperation in large metropolitan areas, whereas in-house R&D of less-experienced younger firms is not influenced greatly by external knowledge. In a science park that is distant from the economic core region, we identified that encouragement by local organization toward R&D by less-experienced younger firms has considerable influence.R&D cooperation, industrial cluster, Seoul Digital Industrial Complex, Daedeok Valley, Zhongguancun Science Park

Centimeter Polarimetry of the R Coronae Australis Region

Circularly polarized 3.5 cm continuum emission was detected toward three radio sources in the R CrA region using the Very Large Array. The Class I protostar IRS 5b persistently showed polarized radio emission with a constant helicity over 8 yr, which suggests that its magnetosphere has a stable configuration. There is a good correlation between the Stokes I and Stokes V fluxes, and the fractional polarization is about 0.17. During active phases the fractional polarization is a weakly decreasing function of Stokes I flux, which suggests that IRS 5b is phenomenologically similar to other types of flare stars such as RS CVn binaries. The variability timescale of the polarized flux is about a month, and the magnetosphere of IRS 5b must be very large in size. The Class I protostar IRS 7A was detected once in circularly polarized radio emission, even though IRS 7A drives a thermal radio jet. This detection implies that the radio emission from the magnetosphere of a young protostar can escape the absorption by the partially ionized wind at least once in a while. The properties of IRS 7A and IRS 5b suggests that Class I protostars have organized peristellar magnetic fields of a few kilogauss and that the detectability of magnetospheric emission may depend on the evolutionary status of protostar. Also reported is the detection of circularly polarized radio emission toward the variable radio source B5.Comment: To appear in the Astrophysical Journa