Positron Line Emission in Very Heavy Ion Collisions: Results from the EPOS Collaboration

摘要: The detection of narrow lines in positron singles- and electron sum-energy spectra measured after heavy-ion collisions at the UNILAC accelerator GSI, Darmstadt has generated increasing interest past years. Whereas line phenomenon itself appears to be experimentally well established, no conceivable explanation is given until today although many different attempts have been made. They reach from conventional processes newly proposed mechanisms, including spontaneous emission long-living quasiatomic formations as production light neutral fundamental particles. This article summarizes some main features they obtained by EPOS collaboration [SalB90]. No attempt made describe experiment full detail; instead we refer [BokS89,Bok87,CowG87,Bok90]. Two other groups, ORANGE [KoeB87,KoeB89] TORI [RheB89] collaborations are also studying these subjects. For results group see contribution W. Koenig this conference. Comprehensive collections theoretical aspects various lectures during school can found e.g. [Gre88,FacT89] a recent review [Mul89].