9 research outputs found
First identification of Zn 58 β -delayed proton emission
7 pags., 6 figs., 2 tabs.The β decay of Zn57 and Zn58 was investigated in an experiment at the National Superconducting Cyclotron Laboratory of Michigan State University. For the first time β-delayed proton emission from Zn58 was observed with a branching ratio of 0.7(1)%. The proton-energy spectrum allowed for probing the Gamow-Teller strength distribution above the proton-separation energy in the daughter nucleus. Moreover, the absolute branching ration for delayed-proton emission from Zn57 was found to be compatible with 100%.Operation of the NSCL was supported by the National Science Foundation under Grant PHY-1102511. This work was supported
by the National Science Center, Poland, under Contract No.
UMO-2015/17/B/ST2/00581, by the US Department of Energy, Office of Science, Office of Nuclear Physics, under
US DOE Grants No. DE-AC05-00OR22725 (ORNL) and
No. DE-FG02-96ER40983 (UTK), by the fund source National Nuclear Security Administration Grant No. DEFC03-
03NA00143, and under the Stewardship Science Academic
Alliance program through DOE Cooperative Agreement No.
DE-FG52-08NA28552 (UTK). A.A.C. acknowledges support
by the Polish Ministry of Science and Higher Education
through Grant No. 0079/DIA/2014/43 (”Grant Diamentowy”). H.S. acknowledges support by the US National Science Foundation under awards PHY-1430152 (JINA Center
for the Evolution of the Elements) and PHY-1102511. P.S.
acknowledges support from MCIU/AEI/FEDER_UE (Spain)
under Grant No. PGC2018-093636-B-I00
Screening Instruments for Monitoring Market Power in Wholesale Electricity Markets Lessons from Applications in Germany
Shape and spin determination of Barbarian asteroids
Context. The so-called Barbarian asteroids share peculiar, but common polarimetric properties, probably related to both their shape and composition. They are named after (234) Barbara, the first on which such properties were identified. As has been suggested, large scale topographic features could play a role in the polarimetric response, if the shapes of Barbarians are particularly irregular and present a variety of scattering/incidence angles. This idea is supported by the shape of (234) Barbara, that appears to be deeply excavated by wide concave areas revealed by photometry and stellar occultations. Aims. With these motivations, we started an observation campaign to characterise the shape and rotation properties of Small Main-Belt Asteroid Spectroscopic Survey (SMASS) type L and Ld asteroids. As many of them show long rotation periods, we activated a worldwide network of observers to obtain a dense temporal coverage. Methods. We used light-curve inversion technique in order to determine the sidereal rotation periods of 15 asteroids and the convergence to a stable shape and pole coordinates for 8 of them. By using available data from occultations, we are able to scale some shapes to an absolute size. We also study the rotation periods of our sample looking for confirmation of the suspected abundance of asteroids with long rotation periods. Results. Our results show that the shape models of our sample do not seem to have peculiar properties with respect to asteroids with similar size, while an excess of slow rotators is most probably confirmed.© 2017 ESO.N.P. acknowledges funding from the Portuguese FCT - Foundation for Science and Technology. CI-TEUC is funded by National Funds through FCT - Foundation for Science and Technology (project: UID/ Multi/00611/2013) and FEDER - European Regional Development Fund through COMPETE 2020 - Operational Programme Competitiveness and Internationalisation (project: POCI-01-0145-FEDER-006922). SARA observations were obtained under the Chilean Telescope Allocation Committee program CNTAC 2015B-4. P.H. acknowledges financial support from the Natural Sciences and Engineering Research Council of Canada, and thanks the staff of Cerro Tololo Inter-American Observatory for technical support. The work of A.M. was supported by grant no. 2014/13/D/ST9/01818 from the National Science Centre, Poland. The research of V.K. is supported by the APVV-15-0458 grant and the VVGS-2016-72608 internal grant of the Faculty of Science, P.J. Safarik University in Kosice. M.K. and O.E. acknowledge TUBITAK National Observatory for a partial support in using T100 telescope with project number 14BT100-648.Peer Reviewe