Fri·Oct 26, 2018Friday·October 26, 2018

1. 01*

   Consequences of broken axial symmetry in heavy nuclei -- an overview of the situation in the valley of stability

   Eckart Grosse🇩🇪 · Arnd R. Junghans🇩🇪 · Jonathan N. Wilson🇫🇷

   An overview on the various effects of axial symmetry breaking is presented for medium heavy and heavy nuclei covering the mass number range 70 < A <240. The discussion includes various observations for nuclei: level densities, spectroscopic features as energies and transition rates, ground state masses and finally the splitting of giant dipole resonances. Quadrupole moments and rates can be derived from models of triaxial rigid rotation or cranking for a given triaxiality parameters {\gamma}, but microscopic considerations are needed to predict these for each nucleus investigated. Respective predictions were made by recently made Hartree- Fock-Bogolyubov (HFB) calculations extended to arbitrary triaxiality by a generator coordinate method. In accord to these, various observations as reported in this overview demonstrate the importance of allowing a breaking of axial symmetry for heavy nuclei already in the valley of stability. Considering this breaking as indicated from the HFB approach surprisingly many experimental data are well described globally without the need for local fit parameters. In addition to these comparisons it will be shown that it is advantageous to consider c{\gamma}=cos(3{\gamma}) an indicator of axiality for heavy nuclei independent of their quadrupole moment.

   nucl-exastro-ph.SRnucl-thPhys.Scripta(2019)·2 citations
2. 02*

   First Measurement of the Ar$(e,e^{\prime })X$ Cross Section at Jefferson Lab

   H. Dai🇺🇸 · M. Murphy🇺🇸 · V. Pandey🇺🇸 · D. Abrams🇺🇸 · D. Nguyen🇺🇸 · B. Aljawrneh🇺🇸 · S. Alsalmi🇺🇸 · A. M. Ankowski🇺🇸 · J. Bane🇺🇸 · S. Barcus🇺🇸 · O. Benhar🇮🇹 · V. Bellini🇮🇹 and 46 other authors

   The success of the ambitious programs of both long- and short-baseline neutrino-oscillation experiments employing liquid-argon time-projection chambers will greatly rely on the precision with which the weak response of the argon nucleus can be estimated. In the E12-14-012 experiment at Jefferson Lab Hall A, we have studied the properties of the argon nucleus by scattering a high-quality electron beam off a high-pressure gaseous argon target. Here, we present the measured ${}^{40}$Ar$(e,e^{\prime })$ double differential cross section at incident electron energy $E=2.222$~GeV and scattering angle $\theta =15.541^{\circ }$. The data cover a broad range of energy transfers, where quasielastic scattering and delta production are the dominant reaction mechanisms. The result for argon is compared to our previously reported cross sections for titanium and carbon, obtained in the same kinematical setup.

   nucl-exhep-exnucl-thPRC(2019)·49 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.