A new upper limit for the probability of spontaneous muonium to antimuonium conversion was established at P MM ≤ 8.2 · 10 −11 (90%C.L.) in 0.1 T magnetic field, which implies consequences for speculative extensions to the standard model. Coupling parameters in R-parity violating supersymmetry and the mass of a flavour diagonal bileptonic gauge boson can be significantly restricted. A Z 8 model with radiative mass generation through heavy lepton seed and the minimal version of 331-GUT models are ruled out.

The Technical Design for the COMET Phase-I experiment is presented in this paper. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of an aluminum nucleus ($\mu$–$e$ conversion, $\mu^{-}N \rightarrow e^{-}N$); a lepton flavor-violating process. The experimental sensitivity goal for this process in the Phase-I experiment is $3.1\times10^{-15}$, or 90% upper limit of a branching ratio of $7\times 10^{-15}$, which is a factor of 100 improvement over the existing limit. The expected number of background events is 0.032. To achieve the target sensitivity and background level, the 3.2 kW 8 GeV proton beam from J-PARC will be used. Two types of detectors, CyDet and StrECAL, will be used for detecting the $\mu$–$e$ conversion events, and for measuring the beam-related background events in view of the Phase-II experiment, respectively. Results from simulation on signal and background estimations are also described.

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New 3 (4 hydroxybenzyl)piperazine 2,5 dione, together with the known N [2 (4 hydroxy phenyl)ethyl]acetamide (N acetyltyramine), was isolated for the first time from the marine actinobacterium Streptomyces sp. The chemical structures of these compounds were deter mined by NMR spectroscopy and mass spectrometry. The cytotoxic activities of the com pounds were estimated from their effects on sperm and eggs of the sea urchin Strongylocentrotus intermedius.

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