Fission decay of N = Z nuclei at high angular momentum: 60^{60}Zn

Using a unique two-arm detector system for heavy ions (the BRS, binary reaction spectrometer) coincident fission events have been measured from the decay of $^{60}$Zn compound nuclei formed at 88MeV excitation energy in the reactions with $^{36}$Ar beams on a $^{24}$Mg target at $E_{lab}(^{36}$Ar) = 195 MeV. The detectors consisted of two large area position sensitive (x,y) gas telescopes with Bragg-ionization chambers. From the binary coincidences in the two detectors inclusive and exclusive cross sections for fission channels with differing losses of charge were obtained. Narrow out-of-plane correlations corresponding to coplanar decay are observed for two fragments emitted in binary events, and in the data for ternary decay with missing charges from 4 up to 8. After subtraction of broad components these narrow correlations are interpreted as a ternary fission process at high angular momentum through an elongated shape. The lighter mass in the neck region consists dominantly of two or three-particles. Differential cross sections for the different mass splits for binary and ternary fission are presented. The relative yields of the binary and ternary events are explained using the statistical model based on the extended Hauser-Feshbach formalism for compound nucleus decay. The ternary fission process can be described by the decay of hyper-deformed states with angular momentum around 45-52 $hbar$.Comment: 23 pages, 25 figure

Homegardens in Uganda. Diversity and Potential

Ugandan homegarden systems are sustainable small-scale solutions for food security and conservation containing a great diversity of native plant species and preserving the associated time-tested traditional knowledge for nutrition and conservation. Furthermore, the people of Uganda have a diversity of uses for these native species. However, these systems and traditions are under threat for a variety of reasons. Organic may hold some of the keys for the revitalization of these oases of diversity and culture. The organic markets in Uganda now sell only a few species but can embrace the great diversity through increasing access to organic markets for more small producers and indigenous plant species

Mehrwertsteuer-Erhebung durch Quellensteuer statt Reverse Charge

Seit der Einführung des Binnenmarktes im Jahre 1993 bis zur sog. Osterweiterung am 1. Mai 2004 haben die EU-Finanzminister im Durchschnitt einmal jährlich das gemeinsame Mehrwertsteuerrecht geändert. Im Europa der 25 haben sie wegen des Einstimmigkeitsprinzips keinen einzigen Änderungsvorschlag der Kommission angenommen. Auch die Mehrwertsteuerberatungen in der letzten Sitzung unter Österreichischer Ratspräsidentschaft sind ergebnislos verlaufen. Das ifo institut schlägt zur Überwindung der Widerstände im EU-Ministerrat ein Quellensteuerverfahren vor, das auf der Fortentwicklung bereits früher angedachter Überlegungen beruht.Umsatzsteuer, Quellensteuer, EU-Staaten

The population of deformed bands in 48^{48}Cr by emission of 8^{8}Be from the 32^{32}S + 24^{24}Mg reaction

Using particle-$\gamma$ coincidences we have studied the population of final states after the emission of 2 $\alpha$-particles and of $^{8}$Be in nuclei formed in $^{32}$S+$^{24}$Mg reactions at an energy of $\textrm{E}_{\rm L}(^{32}\textrm{S}) = 130 {\rm MeV}$. The data were obtained in a setup consisting of the GASP $\gamma$-ray detection array and the multidetector array ISIS. Particle identification is obtained from the $\Delta$E and E signals of the ISIS silicon detector telescopes, the $^{8}$Be being identified by the instantaneous pile up of the $\Delta$E and E pulses. $\gamma$-ray decays of the $^{48}$Cr nucleus are identified with coincidences set on 2 $\alpha$-particles and on $^{8}$Be. Some transitions of the side-band with $K^\pi=4^{-}$ show stronger population for $^{8}$Be emission relative to that of 2 $\alpha$-particles (by a factor $1.5-1.8$). This observation is interpreted as due to an enhanced emission of $^{8}$Be into a more deformed nucleus. Calculations based on the extended Hauser-Feshbach compound decay formalism confirm this observation quantitatively.Comment: 17 pages, 9 figures accepted for publication in J. Phys.

Current in open quantum systems

We show that a dissipative current component is present in the dynamics generated by a Liouville-master equation, in addition to the usual component associated with Hamiltonian evolution. The dissipative component originates from coarse graining in time, implicit in a master equation, and needs to be included to preserve current continuity. We derive an explicit expression for the dissipative current in the context of the Markov approximation. Finally, we illustrate our approach with a simple numerical example, in which a quantum particle is coupled to a harmonic phonon bath and dissipation is described by the Pauli master equation.Comment: To appear in Phys. Rev. Let