text: Search Results: 1 - 10 of 401240 matches for " Hayasaka M "
  Physics , 2007, DOI: 10.1016/j.physletb.2008.06.056
  Abstract: We report on a search for the lepton flavor violating tau- -> mu- gamma and tau- -> e- gamma decays based on 535/fb of data accumulated at the Belle experiment. No signal is found and we set 90% confidence level upper limits on the branching ratios Br(tau- -> mu- gamma) < 4.5x10^-8 and Br(tau- -> e- gamma) < 1.2x10^-7.
  Explosive percolation in thresholded networks
  Abstract: Explosive percolation in a network is a phase transition where a large portion of nodes becomes connected with an addition of a small number of edges. Although extensively studied in random network models and reconstructed real networks, explosive percolation has not been observed in a more realistic scenario where a network is generated by thresholding a similarity matrix describing between-node associations. In this report, I examine construction schemes of such thresholded networks, and demonstrate that explosive percolation can be observed by introducing edges in a particular order.
  Modules of reduction number one
  Abstract: Let (A, m) be a Noetherian local ring and N a parameter module in F=A^r and M=N:_F m the socle module of N. In this paper, we shall prove that the module M=N:_F m has a reduction number at most one and hence its Rees algebra R(M) is Cohen-Macaulay, if the base ring A is Cohen-Macaulay of dimension two and the rank of N is greater than or equal to two. This result gives numerous examples of Cohen-Macaulay Rees algebras of modules, which are not integrally closed and not a parameter module.
  Recent Trends of Fire Occurrence in Sumatra (Analysis Using MODIS Hotspot Data): A Comparison with Fire Occurrence in Kalimantan [PDF]
  Open Journal of Forestry (OJF) , 2013, DOI: 10.4236/ojf.2013.34021
  MODIS (Moderate Resolution Imaging Spectroradiometer) hotspot and precipitation data for the most recent 11-year period (2002 to 2012) were analyzed to elucidate recent trends in the seasonal and spatial fire occurrence in Sumatra and the relationship with precipitation. Using a latitude line of S 0.5°, Sumatra was divided into two regions, N. (north) and S. (south) Sumatra. Different trends in seasonal fire occurrence were discussed and further defined by considering two different precipitation patterns. Analysis of hotspot (fire) data was carried out using 0.5° × 0.5° grid cells to evaluate recent trends of spatial fire occurrence. Analysis results of hotspot and precipitation data were also tallied every 10-day to find the relationship between seasonal fire occurrence and the dry season. Standard deviation (SD) and variance (V) were then used to evaluate fire occurrences in Sumatra and Kalimantan objectively. The relatively mild fire occurrence tendency in Sumatra compared to Kalimantan could be the result of different stages of forest development or the high deforestation rate in Sumatra compared with Kalimantan. This paper also shows that the two different seasonal fire activities in N. and S. Sumatra were closely related to the two different dry season types: a winter and summer dry season type (WD & SD) in N. Sumatra, and a summer dry season type (SD) in S. Sumatra. Extreme fire occurrences in the Dumai region in 2005 and Palembang region in 2006 could be partially explained by a severe drought occurrence enhanced by two different kinds of El Nino events.
  Kiyoshi Hayasaka,Ryuichi Nakayama
  Physics , 1999, DOI: 10.1016/S0370-2693(99)00990-9
  Abstract: It is shown that the effective theory of D-particles has conformal symmetry with field-dependent parameters. This is a consequence of the supersymmetry. The string coupling constant is not transformed in contrast with the recent proposal of generalized conformal symmtery by Jevicki et al. This conformal symmetry can also be generalized to other Dp-brane systems.
  K. Hayasaka,for the Belle collaboration
  Abstract: We report results of a search for tau lepton decays strongly suppressed in the Standard Model based on the world-largest data sample accumulated with the Belle detector at the KEKB asymmetric-energy e+e- collider. The decays include: lepton flavor and lepton number violating tau decays into a lepton (e or mu) and two charged mesons (K or pi) as well as lepton and baryon number violating tau decays into a Lambda and a charged meson (K or pi). The sensitivity to the branching fractions is significantly improved compared to our previous results and reaches O(10^{-8}).
  Abstract: We report the recent results of a search for lepton-flavor-violating tau decays and a search for CP violation in tau to nu Ks pi using a large data sample accumulated with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. The sensitivity to these modes is significantly improved compared to previous experiments.