Mon·Mar 7, 2016Monday·March 7, 2016

1. 01*

   The structure of low-lying states in ${}^{140}$Sm studied by Coulomb excitation

   M. Klintefjord🇳🇴 · K. Hadyńska-Klȩk🇮🇹 · A. Görgen🇳🇴 · C. Bauer🇩🇪 · F.L. Bello Garrote🇳🇴 · S. Bönig🇩🇪 · B. Bounthong🇫🇷 · A. Damyanova🇨🇭 · J.-P. Delaroche🇫🇷 · V. Fedosseev🇨🇭 · D.A. Fink🇨🇭 · F. Giacoppo🇳🇴 and 32 other authors

   The electromagnetic structure of ${}^{140}$Sm was studied in a low-energy Coulomb excitation experiment with a radioactive ion beam from the REX-ISOLDE facility at CERN. The $2^{+}$ and $4^{+}$ states of the ground-state band and a second $2^{+}$ state were populated by multi-step excitation. The analysis of the differential Coulomb excitation cross sections yielded reduced transition probabilities between all observed states and the spectroscopic quadrupole moment for the $2_1^{+}$ state. The experimental results are compared to large-scale shell model calculations and beyond-mean-field calculations based on the Gogny D1S interaction with a five-dimensional collective Hamiltonian formalism. Simpler geometric and algebraic models are also employed to interpret the experimental data. The results indicate that ${}^{140}$Sm shows considerable $\gamma$ softness, but in contrast to earlier speculation no signs of shape coexistence at low excitation energy. This work sheds more light on the onset of deformation and collectivity in this mass region.

   nucl-exPRC(2016)·11 citations
2. 02*

   Galactic survey of 44Ti sources with the IBIS telescope onboard INTEGRAL

   Sergey S. Tsygankov · Roman A. Krivonos🇷🇺 · Alexander A. Lutovinov · Mikhail G. Revnivtsev · Eugene M. Churazov🇩🇪 · Rashid A. Sunyaev🇩🇪 · Sergey A. Grebenev

   We report the results of the deepest Galactic Plane (|b| < 17.5 deg) survey in the 67.9 and 78.4 keV nuclear de-excitation lines of titanium-44 (44Ti) performed using the data acquired with the IBIS/ISGRI instrument onboard the INTEGRAL satellite during 12 years of operation. The peak sensitivity of our survey reached an unprecedented level of $4.8\times 10^{-6}$ erg s${}^{-1}$ cm${}^{-2}$ (3 sigma) that improves the sensitivity of the survey done by CGRO/COMPTEL by a factor of ~5. As a result, constraining upper limits for all sources from the catalog of Galactic supernova remnants (SNRs; Green 2014) are derived. These upper limits can be used to estimate the exposure needed to detect 44Ti emission from any known SNR using existing and prospective X- and gamma-ray telescopes. Among the youngest Galactic SNRs, only Cas A shows significant 44Ti emission flux in good agreement with the NuSTAR measurements. We did not detect any other sources of titanium emission in the Galactic Plane at significance level higher than 5 sigma confirming previous claims of the rarity of such 44Ti-producing SNRs.

   ↳ astro-ph.HEnucl-exMNRAS(2016)·24 citations
3. 03*

   Electromagnetic Simulation and Design of a Novel Waveguide RF Wien Filter for Electric Dipole Moment Measurements of Protons and Deuterons

   J. Slim🇩🇪 · R. Gebel🇩🇪 · D. Heberling🇩🇪 · F. Hinder🇩🇪 · D. Hölscher🇩🇪 · A. Lehrach🇩🇪 · B. Lorentz🇩🇪 · S. Mey🇩🇪 · A. Nass🇩🇪 · F. Rathmann🇩🇪 · L. Reifferscheidt🇩🇪 · H. Soltner🇩🇪 and 3 other authors

   The conventional Wien filter is a device with orthogonal static magnetic and electric fields, often used for velocity separation of charged particles. Here we describe the electromagnetic design calculations for a novel waveguide RF Wien filter that will be employed to solely manipulate the spins of protons or deuterons at frequencies of about 0.1 to 2 MHz at the COoler SYnchrotron COSY at Jülich. The device will be used in a future experiment that aims at measuring the proton and deuteron electric dipole moments, which are expected to be very small. Their determination, however, would have a huge impact on our understanding of the universe.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2016)·51 citations
4. 04*

   White Paper on Nuclear Astrophysics

   Almudena Arcones🇩🇪 · Dan W. Bardayan🇺🇸 · Timothy C. Beers🇺🇸 · Lee A. Berstein · Jeffrey C. Blackmon🇺🇸 · Bronson Messer🇺🇸 · B. Alex Brown · Edward F. Brown · Carl R. Brune🇺🇸 · Art E. Champagne🇺🇸 · Alessandro Chieffi🇮🇹 · Aaron J. Couture🇺🇸 and 31 other authors

   This white paper informs the nuclear astrophysics community and funding agencies about the scientific directions and priorities of the field and provides input from this community for the 2015 Nuclear Science Long Range Plan. It summarizes the outcome of the nuclear astrophysics town meeting that was held on August 21-23, 2014 in College Station at the campus of Texas A&M University in preparation of the NSAC Nuclear Science Long Range Plan. It also reflects the outcome of an earlier town meeting of the nuclear astrophysics community organized by the Joint Institute for Nuclear Astrophysics (JINA) on October 9- 10, 2012 Detroit, Michigan, with the purpose of developing a vision for nuclear astrophysics in light of the recent NRC decadal surveys in nuclear physics (NP2010) and astronomy (ASTRO2010). The white paper is furthermore informed by the town meeting of the Association of Research at University Nuclear Accelerators (ARUNA) that took place at the University of Notre Dame on June 12-13, 2014. In summary we find that nuclear astrophysics is a modern and vibrant field addressing fundamental science questions at the intersection of nuclear physics and astrophysics. These questions relate to the origin of the elements, the nuclear engines that drive life and death of stars, and the properties of dense matter. A broad range of nuclear accelerator facilities, astronomical observatories, theory efforts, and computational capabilities are needed. With the developments outlined in this white paper, answers to long standing key questions are well within reach in the coming decade.

   ↳ astro-ph.SRnucl-exnucl-thPPNP(2017)·55 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.