Fri·May 13, 2016Friday·May 13, 2016

1. 01*

   In-gas-cell laser spectroscopy for magnetic dipole moment of ${}^{199}$Pt toward $N=$ 126

   Y. Hirayama · M. Mukai · Y.X. Watanabe · S.C. Jeong · H.S. Jung · Y. Kakiguchi · S. Kimura · J.Y. Moon · M. Oyaizu · J.H. Park · P. Schury · M. Wada · H. Miyatake

   Magnetic dipole moment and mean-square charge radius of ${}^{199}$Pt ($I^{\pi }=$ 5/2${}^{-}$) have been evaluated for the first time from the investigation of the hyperfine splitting of the ${\lambda }_1=$ 248.792 nm transition by in-gas-cell laser ionization spectroscopy. Neutron-rich nucleus ${}^{199}$Pt was produced by multi-nucleon transfer reaction at the KISS where the nuclear spectroscopy in the vicinity of $N=$ 126 is planed from the aspect of an astrophysical interest as well as the nuclear structure. Measured magnetic dipole moment $+$0.63(13)${\mu }_{\mathrm{N}}$ is consistent with the systematics of those of nuclei with $I^{\pi }=$ 5/2${}^{-}$. The deformation parameter $|<{\beta }_2^2{>}^{1/2}|$ evaluated from the isotope shift indicates the gradual shape change to spherical shape of platinum isotopes with increasing neutron number toward $N=$ 126.

   nucl-exPRC(2017)·23 citations
2. 02*

   In-beam spectroscopy of medium- and high-spin states in ${}^{133}$Ce

   A. D. Ayangeakaa🇺🇸 · U. Garg🇺🇸 · C. M. Petrache🇫🇷 · S. Guo🇫🇷 · P. W. Zhao🇺🇸 · J. T. Matta🇺🇸 · B. K. Nayak🇺🇸 · D. Patel🇺🇸 · R. V. F. Janssens🇺🇸 · M. P. Carpenter🇺🇸 · C. J. Chiara🇺🇸 · F. G. Kondev🇺🇸 and 5 other authors

   Medium and high-spin states in ${}^{133}$Ce were investigated using the ${}^{116}$Cd(${}^{22}$Ne, $5n$) reaction and the Gammasphere array. The level scheme was extended up to an excitation energy of $\sim 22.8$ MeV and spin 93/2 . Eleven bands of quadrupole transitions and two new dipole bands are identified. The connections to low-lying states of the previously known, high-spin triaxial bands were firmly established, thus fixing the excitation energy and, in many cases, the spin parity of the levels. Based on comparisons with cranked Nilsson-Strutinsky calculations and tilted axis cranking covariant density functional theory, it is shown that all observed bands are characterized by pronounced triaxiality. Competing multiquasiparticle configurations are found to contribute to a rich variety of collective phenomena in this nucleus.

   nucl-exPRC(2016)·9 citations
3. 03*

   Predictions for bottomonia suppression in 5.023 TeV Pb-Pb collisions

   Brandon Krouppa🇺🇸 · Michael Strickland🇺🇸

   We compute the suppression of the bottomonia states Upsilon(1S), Upsilon(2S), Upsilon(3S), chi_b(1P), chi_b(2P), and chi_b(3P) states in Large Hadron Collider (LHC) sqrt(s_NN)) = 5.023 TeV Pb-Pb collisions. For the background evolution we use 3+1d anisotropic hydrodynamics with conditions extrapolated from sqrt(s_NN) = 2.76 TeV and we self-consistently compute bottomonia decay rates including non-equilibrium corrections to the interaction potential. For our final results, we make predictions for R_AA as function of centrality, rapidity, and p_T for the Upsilon(1S) and Upsilon(2S) states, including feed down effects. In order to assess the dependence on some of the model assumptions, we vary the shear viscosity-to-entropy density ratio, 4 pi eta/s = (1, 2, 3), and the initial momentum-space anisotropy parameter, xi_0 = (0, 10, 50), while holding the total light hadron multiplicity fixed.

   ↳ hep-phnucl-exnucl-thUniverse(2016)·88 citations
4. 04*

   Effects of the high-momentum tail of nucleon momentum distribution on the isospin-sensitive observables

   Fang Zhang · Gao-Chan Yong🇨🇳

   Based on the Isospin-dependent transport model Boltzmann-Uehling-Uhlenbeck (IBUU), effects of the high momentum tail (HMT) of nucleon momentum distribution in colliding nuclei on some isospin-sensitive observables are studied in the semi-central ${}^{197}\mathrm{Au}{+}^{197}\mathrm{Au}$ reactions at incident beam energy of 400 MeV/nucleon. It is found that the nucleon transverse flow, the difference of neutron and proton transverse flows, the nucleon elliptic flow and free neutron to proton ratio are all less sensitive to the HMT, while the isospin-sensitive nucleon elliptic flow difference is clearly affected by the HMT. Except at very high kinetic energies, the kinetic energy distributions of ${\pi }^{-}$, ${\pi }^{+}$ and charged pion ratio ${\pi }^{-}/{\pi }^{+}$ are all sensitive to the HMT.

   ↳ nucl-thnucl-exEPJA(2016)·14 citations
5. 05*

   Effects of symmetry energy in ${}^{132}\mathrm{Sn}{+}^{124}\mathrm{Sn}$ reaction at 300 MeV/nucleon

   Shan-Jing Cheng🇨🇳 · Gao-Chan Yong🇨🇳 · De-Hua Wen🇨🇳

   Based on the recently updated Isospin-dependent Boltzmann-Uehling-Uhlenbeck (IBUU) transport model, we studied the effects of symmetry energy on the neutron to proton n/p ratio and the ${\pi }^{-}/{\pi }^{+}$ ratio in central ${}^{132}\mathrm{Sn}{+}^{124}\mathrm{Sn}$ reaction at 300 MeV/nucleon. It is found that the n/p ratio and the ${\pi }^{-}/{\pi }^{+}$ ratio in central ${}^{132}\mathrm{Sn}{+}^{124}\mathrm{Sn}$ reaction at 300 MeV/nucleon mainly probe the symmetry energy in the density region 1-1.5 times saturation density. However, the ${\pi }^{-}/{\pi }^{+}$ ratio may be able to probe the density-dependent symmetry energy above 1.5 times saturation density by making some kinematic restrictions such as the azimuthal angle and kinetic energy cuts of emitting pions.

   ↳ nucl-thnucl-exPRC(2016)·13 citations
6. 06*

   Exploratory investigation of the HIPPO gas-jet target fluid dynamic properties

   Zach Meisel🇺🇸 · Ke Shi · Aleksandar Jemcov · Manoel Couder🇺🇸

   In order to optimize the performance of gas-jet targets for future nuclear reaction measurements, a detailed understanding of the dependence of the gas-jet properties on experiment design parameters is required. Common methods of gas-jet characterization rely on measuring the effective thickness using nuclear elastic scattering and energy loss techniques; however, these tests are time intensive and limit the range of design modifications which can be explored to improve the properties of the jet as a nuclear reaction target. Thus, a more rapid jet-characterization method is desired. We performed the first steps towards characterizing the gas-jet density distribution of the HIPPO gas-jet target at the University of Notre Dame's Nuclear Science Laboratory by reproducing results from ${}^{20}\mathrm{Ne}(\alpha ,\alpha {)}^{20}\mathrm{Ne}$ elastic scattering measurements with computational fluid dynamics (CFD) simulations performed with the state-of-the-art CFD software ANSYS Fluent. We find a strong sensitivity to experimental design parameters of the gas-jet target, such as the jet nozzle geometry and ambient pressure of the target chamber. We argue that improved predictive power will require moving to three-dimensional simulations and additional benchmarking with experimental data.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2016)·6 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.