15149590
Brane-antibrane action from boundary string field theory
In this paper we give the boundary string field theory description of brane-antibrane systems. From the world-sheet action of brane-antibrane systems we obtain the tachyon potential and discuss the tachyon condensation exactly. We also find the world-volume action including the gauge fields. Moreover we determine RR-couplings exactly for non-BPS branes and brane-antibranes. These couplings are written by superconnections and correspond to K1(M) and K0(M) for the non-BPS branes and brane-antibranes, respectively. We also show that Myers terms appear if we include the transverse scalars in the boundary sigma model action.
15121439
Orbifolds as Melvin geometry
In this paper we explicitly show that the various non-compact abelian orbifolds are realized as special limits of parameters in type-II (NSNS) Melvin background and its higher-dimensional generalizations. As a result the supersymmetric ALE spaces (A-type 2/N) and non-supersymmetric orbifolds in type-II and type-0 theory are all connected with each other by the exactly marginal deformation. Our results provide new examples of the duality between type-II and type-0 string theory. We also discuss the decay of unstable backgrounds in this model which include closed string tachyons.
135200451
Beam loading in JHF 50 GeV proton synchrotron
123634066
BEAM STUDY OF FFAG ACCELERATOR AT KURRI
In Kyoto University Research Reactor Institute (KURRI), The FFAG accelerator complex for accelerator driven sub-critical reactor (ADSR) project has been already constructed and world first ADSR experiment has been done at March, 2009. In the main ring, proton beams of 11.5MeV are injected and accelerated up to 100MeV. During the acceleration, two different types of beam loss have been observed. To investigate these beam losses, betatron tune and synchrotron oscillation phase have been measured experimentally. The details of measurements will be described in this presentation.