Nonlinearizable actions of dihedral groups on affine space

Let be a reductive, non-abelian, algebraic group defined over . We investigate algebraic -actions on the total spaces of non-trivial algebraic -vector bundles over -modules with great interest in the case that is a dihedral group. We construct a map classifying such actions of a dihedral group in some cases and describe the spaces of those non-linearizable actions in some examples.

     

Production and decay of the isotope 271 Ds (Z = 110)

Production and decay of the isotope ²⁷¹Ds were studied. The isotope was produced by ²⁰⁸Pb + ⁶⁴Ni ²⁷¹Ds + n reaction. Fourteen -decay chains have been assigned to decays originating from the isotope ²⁷¹Ds. An excitation function of the production of this isotope was measured. The results have provided a good confirmation of production and decay of ²⁷¹Ds reported by Hofmann et al. The presence of an isomeric state in ²⁷¹Ds has been confirmed. The existence of a possible isomeric state in ²⁶⁷Hs is presented.Received: 22 September 2003, Revised: 26 December 2002, Published online: 10 August 2004PACS: 23.60. + e decay - 25.70.-z Low and intermediate energy heavy-ion reactions - 27.90. + b D. Kaji: Present address: Center for Nuclear Science, University of Tokyo, Wako-shi, Saitama 351-0198, Japan.A. Ozawa: Present address: University of Tsukuba, Tsukuba, Ibaragi 3058 577, Japan.     

Nuclear Spin Orientation Created in Heavy Ion Collisions and the Sign of the Q Moment of 13B

The momentum dependences of the nuclear spin polarization P and alignment A of ¹³B(, T _1/2 = 17.36 ms) produced in the 100A MeV ¹⁵N + Be collisions have been measured by detecting β-ray asymmetry. Because both the P and A were significantly smaller than the prediction from a simple kinematical model, some relaxation mechanisms must be take into account. Comparing the signs of the observed alignment of ¹²B, the sign of the quadrupole coupling constant eqQ of ¹³B in TiO₂ was determined to be positive.     

Synthesis of 3-acyl-1-alkyl-2-alkylseleno-1-cyclobutene using alkyneselenolate

The reaction of lithium alkyneselenolate with alpha,beta-unsaturated ketone and then alkyl or acyl halide afforded 3-acyl-1-alkyl-2-alkylseleno-1-cyclobutene. The structure of the cyclobutene was elucidated by IR, MS, (1)H, (13)C, and (77)Se NMR, COSY, HMQC, and HMBC data and X-ray analysis.     

1,2-cyclic sulfamidates as versatile precursors to thiomorpholines and piperazines

[reaction: see text] 1,2-Cyclic sulfamidates undergo regiospecific nucleophilic displacement with either methyl thioglycolate or alpha-amino esters, followed by lactamization (thermal, base-mediated, or cyanide-catalyzed), to give thiomorpholin-3-ones and piperazin-2-ones.     

Pyrolysis of azidopyrazines

2,3-Dichloro- and 2,5-dichloropyrazines were treated with sodium azide. The former gave diazidopyrazines and the latter, monoazidomonochloropyrazines. Pyrolysis of 2,3-diazidopyrazines resulted the production of 1,2-dicyanoiminoethanes and that of 2-azido-5-chloropyrazines, chloroimidazoles.     

Results from DASP one + e − annihilation between 3.1 and 5.2 GeV

This paper summarizes the measurements one ⁺ e ^? annihilation performed by the DASP Collaboration in the energy range between 3.1 and 5.2 GeV. The following topics are covered: total cross section, production and two body decays of the narrow resonances, radiative decays of theJ/ψ and ψ′ resonances and evidence for theX(2.82), ψ′ cascade decays, inclusive η production and evidence for theF meson, semileptonic decays of charmed mesons and properties of the heavy lepton.