Tue·Jun 12, 2018Tuesday·June 12, 2018

1. 01*

   Modeling of two-particle femtoscopic correlations at top RHIC energy

   N. Ermakov🇷🇺 · G. Nigmatkulov🇷🇺

   The spatial and temporal characteristics of particle emitting source produced in particle and/or nuclear collisions can be measured by using two-particle femtoscopic correlations. These correlations arise due to quantum statistics, Coulomb and strong final state interactions. In this paper we report on the calculations of like-sign pion femtoscopic correlations produced in p+p, p+Au, d+Au, Au+Au at top RHIC energy using Ultra Relativistic Quantum Molecular Dynamics Model (UrQMD). Three-dimensional correlation functions are constructed using the Bertsch-Pratt parametrization of the two-particle relative momentum. The correlation functions are studied in several transverse mass ranges. The emitting source radii of charged pions, Rout , Rside , Rlong , are obtained from Gaussian fit to the correlation functions and compared to data from the STAR and PHENIX experiments.

   nucl-exnucl-thJ.Phys.Conf.Ser.(2017)·5 citations
2. 02*

   Nuclear charge radii of ${}^{229}$Th from isotope and isomer shifts

   M. S. Safronova🇺🇸 · S. G. Porsev🇺🇸 · M. G. Kozlov🇷🇺 · J. Thielking · M. V. Okhapkin · P. Głowacki · D. M. Meier · E. Peik🇩🇪

   The isotope ${}^{229}$Th is unique in that it possesses an isomeric state of only a few eV above the ground state, suitable for nuclear laser excitation. An optical clock based on this transition is expected to be a very sensitive probe for variations of fundamental constants, but the nuclear properties of both states have to be determined precisely to derive the actual sensitivity. We carry out isotope shift calculations in Th${}^{+}$ and Th${}^{2+}$ including the specific mass shift, using a combination of configuration interaction and all-order linearized coupled-cluster methods and estimate the uncertainty of this approach. We perform experimental measurements of the hyperfine structure of Th${}^{2+}$ and isotopic shift between ${}^{229}$Th${}^{2+}$ and ${}^{232}$Th${}^{2+}$ to extract the difference in root-mean-square radii as $\delta ⟨r^2{⟩}^{232,229}=0.299(15)$ fm${}^2$. Using the recently measured values of the isomer shift of lines of ${}^{229\text{m}}$Th, we derive the value for the mean-square radius change between ${}^{229}$Th and its low lying isomer ${}^{229\text{m}}$Th to be $\delta ⟨r^2{⟩}^{229\text{m},229}=0.0105(13){\mathrm{fm}}^2$.

   ↳ physics.atom-phnucl-exnucl-thquant-phPRL(2018)·27 citations
3. 03*

   Explicit inclusion of spin-orbit contribution in THSR wave function

   N. Itagaki🇯🇵 · H. Matsuno🇯🇵 · A. Tohsaki🇯🇵

   The Tohsaki-Horiuchi-Schuck-Roepke (THSR) wave function has been successfully used for the studies of gas-like nature of alpha clusters in various nuclei including the so-called Hoyle state of 12C and four alpha states of 16O. In standard alpha cluster models, however, each alpha cluster wave function has spin zero because of its spatial symmetry and antisymmetrization effect. Thus the non-central interactions do not contribute, and this situation is the same in the THSR wave function. In this work, the spin-orbit contribution, which is found to be quite important at short alpha-alpha distances, is taken into account in the THSR wave function by combing it with antisymmetrized quasi cluster model (AQCM). The application to 12C is presented. The multi-integration in the original THSR wave function is carried out by using Monte Carlo technique, which is called Monte Carlo THSR wave function. For the nucleon-nucleon interaction, the Tohsaki interaction, which contains finite-range three-body terms and simultaneously reproduces the saturation properties of nuclear systems, the alpha-alpha scattering phase shift, and the size and binding energy of 4He, is adopted.

   ↳ nucl-thnucl-exPRC(2018)·17 citations
4. 04*

   Optimization of RPCs read-out panel with electromagnetic simulation

   E. Alunno Camelia🇮🇹 · R. Cardarelli🇮🇹 · A. Di Ciaccio🇮🇹 · S. Bruno🇮🇹 · A. Caltabiano🇮🇹 · P. Camarri🇮🇹 · B. Liberti🇮🇹 · L. Massa🇮🇹 · L. Pizzimento🇮🇹 · A. Rocchi🇮🇹

   With the upgrade of the RPCs [1]-[2] and the increase of its performances, the study and the optimization of the read-out panel is necessary in order to maintain the signal integrity and to reduce the intrinsic crosstalk. Through Electromagnetic Simulation, performed with CST Studio Suite, new panels design are tested and their crosstalk property are studied. The behavior of different type of panel is shown, in particular a panel with the decoupling strip connected through their characteristic impedance to the ground plane is simulated.

   ↳ physics.ins-detnucl-exJINST(2019)·0 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.