Tue·Jul 4, 2017Tuesday·July 4, 2017

1. 01*

   Confirmation of the isomeric state in 26P

   D. Pérez-Loureiro🇺🇸 · C. Wrede🇺🇸 · M. B. Bennett🇺🇸 · S. N. Liddick🇺🇸 · A. Bowe · B. A. Brown🇺🇸 · A. A. Chen🇹🇼 · K. A. Chipps🇺🇸 · N. Cooper🇬🇧 · E. McNeice · F. Naqvi · R. Ortez and 11 other authors

   We report the independent experimental confirmation of an isomeric state in the proton drip-line nucleus ${}^{26}$P. The $\gamma$-ray energy and half-life determined are 164.4 $\pm$ 0.3 (sys) $\pm$ 0.2 (stat) keV and 104 $\pm$ 14 ns, respectively, which are in agreement with the previously reported values. These values are used to set a semi-empirical limit on the proton separation energy of ${}^{26}$P, with the conclusion that it can be bound or unbound.

   nucl-exPRC(2017)·3 citations
2. 02*

   Study of the in-medium nucleon electromagnetic form factors using a light-front nucleon wave function combined with the quark-meson coupling model

   W. R. B. de Aráujo (Secretaria de Educaçao do Estado de São Paulo)🇧🇷 · J.P. B. C. de Melo🇧🇷 · K. Tsushima (Laboratório de Física Teórica e Computacional, Universidade Cruzeiro do Sul)🇧🇷

   We study the nucleon electromagnetic (EM) form factors in symmetric nuclear matter as well as in vacuum within a light-front approach using the in-medium inputs calculated by the quark-meson coupling model. The same in-medium quark properties are used as those used for the study of in-medium pion properties. The zero of the proton EM form factor ratio in vacuum, the electric to magnetic form factor ratio ${\mu }_p{G}_{Ep}(Q^2)/G_{Mp}(Q^2)$ ($Q^2=-q^2>0$ with $q$ being the four-momentum transfer), is determined including the latest experimental data by implementing a hard constituent quark component in the nucleon wave function. A reasonable fit is achieved for the ratio ${\mu }_p{G}_{Ep}(Q^2)/G_{Mp}(Q^2)$ in vacuum, and we predict that the $Q_0^2$ value to cross the zero of the ratio to be about 15 GeV${}^2$. In addition the double ratio data of the proton EM form factors in ${}^4$He and H nuclei, $[G_{Ep}^{{}^4\mathrm{He}}(Q^2)/G_{Mp}^{{}^4\mathrm{He}}(Q^2)]/[G_{Ep}^{{}^1\mathrm{H}}(Q^2)/G_{Mp}^{{}^1\mathrm{H}}(Q^2)]$, extracted by the polarized ($\vec{e},e^{\prime }\vec{p}$) scattering experiment on ${}^4$He at JLab, are well described. We also predict that the $Q_0^2$ value satisfying ${\mu }_p{G}_{Ep}(Q_0^2)/G_{Mp}(Q_0^2)=0$ in symmetric nuclear matter, shifts to a smaller value as increasing nuclear matter density, which reflects the facts that the faster falloff of $G_{Ep}(Q^2)$ as increasing $Q^2$ and the increase of the proton mean-square charge radius. Furthermore, we calculate the neutron EM form factor double ratio in symmetric nuclear matter for $0.1<Q^2<1.0$ GeV${}^2$. The result shows that the neutron double ratio is enhanced relative to that in vacuum, while for the proton it is quenched, and agrees with an existing theoretical prediction.

   ↳ hep-phhep-exnucl-exnucl-thNPA(2018)·14 citations
3. 03*

   Structure of krypton isotopes within the interacting boson model derived from the Gogny energy density functional

   K. Nomura🇫🇷 · R. Rodríguez-Guzmán🇰🇼 · Y. M. Humadi · L. M. Robledo🇪🇸 · H. Abusara

   The evolution and coexistence of the nuclear shapes as well as the corresponding low-lying collective states and electromagnetic transition rates are investigated along the Krypton isotopic chain within the framework of the interacting boson model (IBM). The IBM Hamiltonian is determined through mean-field calculations based on the several parametrizations of the Gogny energy density functional and the relativistic mean-field Lagrangian. The mean-field energy surfaces, as functions of the axial $\beta$ and triaxial $\gamma$ quadrupole deformations, are mapped onto the expectation value of the interacting-boson Hamiltonian that explicitly includes the particle-hole excitations. The resulting boson Hamiltonian is then used to compute low-energy excitation spectra as well as E2 and E0 transition probabilities for ${}^{70-100}$Kr. Our results point to a number of examples of the prolate-oblate shape transitions and coexistence both on the neutron-deficient and neutron-rich sides. A reasonable agreement with the available experimental data is obtained for the considered nuclear properties.

   ↳ nucl-thnucl-exPRC(2017)·26 citations
4. 04*

   Research on the halo in ${}^{31}$Ne with complex momentum representation method

   Ya-Juan Tian · Quan Liu🇨🇳 · Tai-Hua Heng · Jian-You Guo🇨🇳

   Halo is one of the most interesting phenomena in exotic nuclei especially for ${}^{31}$Ne, which is deemed to be a halo nucleus formed by a $p-$wave resonance. However, the theoretical calculations don't suggest a $p-$wave resonance using the scattering phase shift approach or complex scaling method. Here, we apply the complex momentum representation method to explore resonances in ${}^{31}$Ne. We have calculated the single-particle energies for bound and resonant states together with their evolutions with deformation. The results show that the $p-$wave resonances appear clearly in the complex momentum plane accompanied with the $p-f$ inversion in the single-particle levels. As it happens the $p-f$ inversion, the calculated energy, width, and occupation probabilities of major components in the level occupied by valance neutron support a $p-$wave halo for ${}^{31}$Ne.

   ↳ nucl-thnucl-exPRC(2017)·19 citations
5. 05*

   General formalism of collective motion for any deformed system

   Jian-You Guo🇨🇳

   Based on Bohr model, we have presented a general formalism describing the collective motion for any deformed system, in which the collective Hamiltonian is expressed as vibrations in the body-fixed frame, rotation of whole system around the laboratory frame, and coupling between vibrations and rotation. Under the condition of decoupling approximation, we have derived the quantized Hamiltonian operator. Based on the operator, we have calculated the rotational spectra for some special octupole and hexadecapole deformed systems, and shown their dependencies on deformation. The result indicates that the contribution of octupole or hexadecapole deformations to the lowest band is regular, while that to higher bands is dramatic. These features reflecting octupole and hexadecapole deformations are helpful to recognize the properties of real nuclei with octupole and/or hexadecapole deformations coexisting with quadrupole deformations.

   ↳ nucl-thnucl-exPRC(2015)·4 citations
6. 06*

   The Spin and Orbital Contributions to Magnetic Dipole Transitions

   Arun Kingan · Michael Quinonez · Xiaofei Yu · Larry Zamick🇺🇸

   In previous works we examined they systematics of magnetic dipole transitions in a single j shell. We here extend the study to large space calculations.We consider the nuclei ${}^{44}$ Ti, ${}^{46}$Ti and ${}^{48}$C. Of particular interest is the contributions to B(M1) of the spin and orbital parts of the magnetic dipole operator. Whereas usual scissors mode analyses have as an initial state the J=0+ ground state (of an even-even nucleus) we here start with the lowest J=1+ T=1 state. This enables us to reach many more states e.g. J=2,T=0,1, and 2 and thus getter a better picture of the collectivity of this state.

   ↳ nucl-thnucl-exIJMPE(2018)·9 citations
7. 07*

   Odd J states of isospin zero and one for 4 nucleon systems: near degeneracies

   Arun Kingan · Larry Zamick🇺🇸

   In this work we calculate the energies odd J${}^{+}$ states in selectedeven-even nuclei-${}^{44}$ Ti ${}^{52}$ Fe and ${}^{96}$Cd. Of particularinterest is the fact that in many cases the first T=0 and the first T=1 state are close in energy. Whether the lowest odd J state hasT=0 or T=1 is here considered.

   ↳ nucl-thnucl-exPRC(2018)·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.