Thu·Jul 9, 2015Thursday·July 9, 2015

1. 01*

   A search for double-electron capture in 74Se using coincidence/anticoincidence gamma-ray spectrometry

   M. Jeskovsky (1)🇸🇰 · D. Frekers (2)🇩🇪 · A. Kovacik (1)🇸🇰 · P. P. Povinec (1)🇸🇰 · P. Puppe (2) · J. Stanicek (1)🇸🇰 · I. Sykora (1)🇸🇰 · F. Simkovic (1,3)🇸🇰 · J.H. Thies (2) ((1) Comenius University, Faculty of Mathematics, Physics and Informatics, Department of Nuclear Physics and Biophysics, 84248 Bratislava, Slovakia, (2) Institut für Kernphysik, Westfälische Wilhelms Universität, Münster, Germany, (3) Joint Institute for Nuclear Research, Dubna, Moscow Region, Russian Federation)🇩🇪

   Evaluation of single, coincidence and anticoincidence gamma-ray spectrometry methods has been carried out with the aim to search for double-electron capture in 74Se. This process is unique, because there is probability for transition to the 2+ excited state in 74Ge (1204 keV), and de-excitation through two gamma-quanta cascade with energies of 595.9 keV and 608.4 keV. Long-term measurements with anticosmic shielded HPGe spectrometer and the coincidence HPGe-NaI(Tl) spectrometer did not show any evidence for the double-electron capture in 74Se. The best limit for the half-life of the double electron capture in 74Se (both for the neutrinoless and two neutrino processes) was estimated to be >1.5x10E19 years.

   nucl-exphysics.ins-detNucl.Instrum.Meth.A(2015)·9 citations
2. 02*

   Investigating the nature of light scalar mesons with semileptonic decays of D mesons

   Takayasu Sekihara (Osaka U., RCNP)🇯🇵 · Eulogio Oset (Valencia U. & Valencia U., IFIC)🇪🇸

   We study the semileptonic decays of $D_s^{+}$, $D^{+}$, and $D^0$ mesons into the light scalar mesons [$f_0(500)$, $K_0^{\ast }(800)$, $f_0(980)$, and $a_0(980)$] and the light vector mesons [$\rho (770)$, $\omega (782)$, $K^{\ast }(892)$, and $\varphi (1020)$]. With the help of a chiral unitarity approach in coupled channels, we compute the branching fractions for scalar meson processes of the semileptonic $D$ decays in a simple way. Using current known values of the branching fractions, we make predictions for the branching fractions of the semileptonic decay modes with other scalar and vector mesons. Furthermore, we calculate the ${\pi }^{+}{\pi }^{-}$, $\pi \eta$, $\pi K$, and $K^{+}{K}^{-}$ invariant mass distributions in the semileptonic decays of $D$ mesons, which will help us clarify the nature of the light scalar mesons.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2015)·64 citations
3. 03*

   Extending the applicability of an open-ring trap to perform experiments with a single laser-cooled ion

   J.M. Cornejo · M. Colombano · J. Doménech · M. Block🇩🇪 · P. Delahaye🇫🇷 · D. Rodríguez🇺🇸

   An open-ring ion trap, also referred to as transparent trap was initially built up to perform $\beta$-$\nu$ correlation experiments with radioactive ions. This trap geometry is also well suited to perform experiments with laser-cooled ions, serving for the development of a new type of Penning trap, in the framework of the project TRAPSENSOR at the University of Granada. The goal of this project is to use a single ${}^{40}$Ca${}^{+}$ ion as detector for single-ion mass spectrometry. Within this project and without any modification to the initial electrode configuration, it was possible to perform Doppler cooling on ${}^{40}$Ca${}^{+}$ ions, starting from large clouds and reaching single ion sensitivity. This new feature of the trap might be important also for other experiments with ions produced at Radioactive Ion Beam (RIB) facilities. In this publication, the trap and the laser system will be described, together with their performance with respect to laser cooling applied to large ion clouds down to a single ion.

   ↳ physics.ins-detnucl-exphysics.atom-phRev.Sci.Instrum.(2015)·8 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.