Mon·Jun 19, 2017Monday·June 19, 2017

1. 01*

   $N^{\ast }\to N{\eta }^{\prime }$ decays from photoproduction of ${\eta }^{\prime }$-mesons off protons

   A.V. Anisovich🇩🇪 · V. Burkert🇺🇸 · P.M. Collins🇺🇸 · M. Dugger🇺🇸 · E. Klempt🇩🇪 · V.A. Nikonov🇩🇪 · B.G. Ritchie🇺🇸 · A. Sarantsev🇩🇪 · U. Thoma🇩🇪

   A study of the partial-wave content of the $\gamma p\to {\eta }^{\prime }p$ reaction in the fourth resonance region is presented, which has been prompted by new measurements of polarization observables for that process. Using the Bonn-Gatchina partial-wave formalism, the incorporation of new data indicates that the $N(1895)1/2^{-}$, $N(1900)3/2^{+}$, $N(2100)1/2^{+}$, and $N(2120)3/2^{-}$ are the most significant contributors to the photoproduction process. New results for the branching ratios of the decays of these more prominent resonances to $N{\eta }^{\prime }$ final states are provided; such branches have not been indicated in the most recent edition of the Review of Particle Properties. Based on the analysis performed here, predictions for the helicity asymmetry $E$ for the $\gamma p\to {\eta }^{\prime }p$ reaction are presented.

   nucl-exPLB(2017)·24 citations
2. 02*

   Cosmogenic Activation of Germanium Used for Tonne-Scale Rare Event Search Experiments

   W.-Z. Wei🇺🇸 · D.-M. Mei🇺🇸 · C. Zhang🇺🇸

   We report a comprehensive study of cosmogenic activation of germanium used for tonne-scale rare event search experiments. The germanium exposure to cosmic rays on the Earth's surface are simulated with and without a shielding container using Geant4 for a given cosmic muon, neutron, and proton energy spectrum. The production rates of various radioactive isotopes are obtained for different sources separately. We find that fast neutron induced interactions dominate the production rate of cosmogenic activation. Geant4-based simulation results are compared with the calculation of ACTIVIA and the available experimental data. A reasonable agreement between Geant4 simulations and several experimental data sets is presented. We predict that cosmogenic activation of germanium can set limits to the sensitivity of the next generation of tonne-scale experiments.

   nucl-exphysics.ins-detAstropart.Phys.(2017)·24 citations
3. 03*

   Quasicontinuum $\gamma$-decay of ${}^{91,92}$Zr: benchmarking indirect ($n,\gamma$) cross section measurements for the $s$-process

   M. Guttormsen🇳🇴 · S. Goriely🇧🇪 · A. C. Larsen🇳🇴 · A. Görgen🇳🇴 · T. W. Hagen🇳🇴 · T. Renstrøm🇳🇴 · S. Siem🇳🇴 · N. U. H. Syed · G. Tagliente🇮🇹 · H. K. Toft · H. Utsunomiya🇯🇵 · A. V. Voinov🇺🇸 · K. Wikan

   Nuclear level densities (NLDs) and $\gamma$-ray strength functions ($\gamma$SFs) have been extracted from particle-$\gamma$ coincidences of the ${}^{92}$Zr($p,p^{\prime }\gamma$)${}^{92}$Zr and ${}^{92}$Zr($p,d\gamma$)${}^{91}$Zr reactions using the Oslo method. The new ${}^{91,92}$Zr $\gamma$SF data, combined with photonuclear cross sections, cover the whole energy range from $E_{\gamma }\approx 1.5$~MeV up to the giant dipole resonance at $E_{\gamma }\approx 17$~MeV. The wide-range $\gamma$SF data display structures at $E_{\gamma }\approx 9.5$~MeV, compatible with a superposition of the spin-flip $M1$ resonance and a pygmy $E1$ resonance. Furthermore, the $\gamma$SF shows a minimum at $E_{\gamma }\approx 2-3$~MeV and an increase at lower $\gamma$-ray energies. The experimentally constrained NLDs and $\gamma$SFs are shown to reproduce known ($n,\gamma$) and Maxwellian-averaged cross sections for ${}^{91,92}$Zr using the {\sf TALYS} reaction code, thus serving as a benchmark for this indirect method of estimating ($n,\gamma$) cross sections for Zr isotopes.

   nucl-exPRC(2017)·35 citations
4. 04*

   Investigation of pion-induced $f_1(1285)$ production off a nucleon target within an interpolating Reggeized approach

   Xiao-Yun Wang🇨🇳 · Jun He🇨🇳

   In this work, the pion-induced $f_1(1285)$ production off a nucleon target is investigated in an effective Lagrangian approach with an interpolating Reggeized treatment in a large range of the pion-beam momentum from threshold up to several tens of GeV. The $s$-channel, $u$-channel, and $t$-channel Born terms are included to calculate production cross sections. An interpolating Reggeized treatment is applied to the $t$ channel, which is found to be important to reproduce the behavior of the existent experimental total cross sections at both low ($\lesssim$ 8 GeV) and high pion-beam momenta ($\gtrsim$ 8 GeV). It is found that the $t$-channel contribution is dominant in the pion-induced $f_1(1285)$ production at low beam momentum and still dominant at very forward angles at high momentum. The interpolated Reggeized treatment of the $u$ channel is also discussed. The $u$-channel contribution is small and negligible at low momentum, and it becomes dominant at backward angles at momenta higher than 10 GeV. The differential cross sections are predicted with the model fixed by the fitting existent experimental data. The results are helpful to the possible experiments at J-PARC and COMPASS.

   ↳ hep-phhep-exnucl-exPRD(2017)·14 citations
5. 05*

   Open heavy-flavour measurements in pp and p--Pb collisions with ALICE at the LHC

   Jaime Norman (for the ALICE collaboration)🇬🇧

   The ALICE detector is well suited to measure heavy-flavour (charm and beauty) production via hadronic and semi-leptonic decay channels of heavy-flavour particles. Here an overview of heavy-flavour measurements made with the ALICE detector during Run 1 in pp and p--Pb collisions is presented and discussed.

   ↳ hep-exnucl-exPoS(2017)·1 citation

* 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.