Wed·May 5, 2021Wednesday·May 5, 2021

1. 01*

   Stopping power of fission fragments in thin Mylar and nickel foils

   T. Materna🇫🇷 · E. Berthoumieux🇫🇷 · Q. Deshayes🇫🇷 · D. Doré🇫🇷 · M. Kebbiri🇫🇷 · A. Letourneau🇫🇷 · L. Thulliez🇫🇷 · Y.H. Kim🇫🇷 · U. Köster🇫🇷 · X. Ledoux🇫🇷

   The energy loss of heavy ions in thin Mylar and nickel foils was measured accurately using fission fragments from ${}^{239}Pu(n_{th},f)$, mass and energy separated by the Lohengrin separator at ILL. The detection setup, placed at the focal plane of the Lohengrin separator enabled to measure precisely the kinetic energy difference of selected fragments after passing through the sample. From these data, the stopping powers in Mylar and nickel layers were extracted and compared to calculations. Whereas large deviations are observed with SRIM-2013 for Mylar, fairly good agreements are obtained with the semi-empirical approach of Knyazheva et al. and the calculations contained within the DPASS database. In nickel, SRIM-2013 and Knyazheva model are in agreement with our data within about 10 %, while large deviations are observed with DPASS. We used our data to provide updated parameters for the Knyazheva et al. model and rescale DPASS database for nickel and Mylar.

   nucl-exphysics.ins-detNucl.Instrum.Meth.B(2021)·2 citations
2. 02*

   The impact of nuclear deformation on relativistic heavy-ion collisions: assessing consistency in nuclear physics across energy scales

   Giuliano Giacalone🇩🇪 · Jiangyong Jia🇺🇸 · Chunjian Zhang🇺🇸

   In the hydrodynamic framework of heavy-ion collisions, elliptic flow, $v_2$, is sensitive to the quadrupole deformation, $\beta$, of the colliding ions. This enables one to test whether the established knowledge on the low-energy structure of nuclei is consistent with collider data from high-energy experiments. We derive a formula based on generic scaling laws of hydrodynamics to relate the difference in $v_2$ measured between collision systems that are close in size to the value of $\beta$ of the respective species. We validate our formula in simulations of 238U+238U and 197Au+197Au collisions at top Relativistic Heavy Ion Collider (RHIC) energy, and subsequently apply it to experimental data. Using the deformation of 238U from low-energy experiments, we find that RHIC $v_2$ data implies $0.16\lesssim |\beta |\lesssim 0.20$ for 197Au nuclei, i.e., significantly more deformed than reported in the literature, posing an interesting puzzle in nuclear phenomenology.

   ↳ nucl-thhep-phnucl-exPRL(2021)·124 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.