Thu·May 17, 2018Thursday·May 17, 2018

1. 01*

   A New Measurement of the Intruder Configuration in 12Be

   J. Chen · J.L. Lou🇨🇳 · Y.L. Ye🇨🇳 · Z.H. Li · D.Y. Pang🇨🇳 · C.X. Yuan🇨🇳 · Y.C. Ge🇨🇳 · Q.T. Li🇨🇳 · H. Hua🇨🇳 · D.X. Jiang🇨🇳 · X.F. Yang🇨🇳 · F.R. Xu🇨🇳 and 19 other authors

   A new ${}^{11}$Be($d,p$)${}^{12}$Be transfer reaction experiment was carried out in inverse kinematics at 26.9$A$ MeV, with special efforts devoted to the determination of the deuteron target thickness and of the required optical potentials from the present elastic scattering data. In addition, a direct measurement of the cross sections for the 0${}_2^{+}$ state was realized by applying an isomer-tagging technique. The s-wave spectroscopic factors of 0.20(0.04) and 0.41(0.11) were extracted for the 0${}_1^{+}$ and 0${}_2^{+}$ states, respectively, in ${}^{12}$Be. Using the ratio of these spectroscopic factors, together with the previously reported results for the p-wave components, the single-particle component intensities in the bound 0${}^{+}$ states of ${}^{12}$Be were deduced, allowing a direct comparison with the theoretical predictions. It is evidenced that the ground-state configuration of ${}^{12}$Be is dominated by the d-wave intruder, exhibiting a dramatic evolution of the intruding mechanism from ${}^{11}$Be to ${}^{12}$Be, with a persistence of the $N=8$ magic number broken.

   nucl-exPLB(2018)·37 citations
2. 02*

   Precise measurement of energy of the first excited state of 115Sn (Eexc = 497.3 keV)

   V.A. Zheltonozhsky · A.M. Savrasov · N.V. Strilchuk · V.I. Tretyak🇺🇦

   Single beta decay of 115In to the first excited level of 115Sn (Eexc = 497.3 keV) is known as beta decay with the lowest Q value. To determine the Q precisely, one has to measure very accurately the Eexc value. A sample of tin enriched in 115Sn to 50.7% was irradiated by proton beam at the U-120 accelerator of INR, Kyiv. The 115Sb radioactive isotope, created in 115Sn(p,n)115Sb reaction, decays with T1/2 = 32 min to 115Sn populating the 497 keV level with ~ 96% probability. The total statistics of ~ 10^5 counts collected in the 497 keV peak in series of measurements, exact description of the peak shape and precisely known calibration points around the 497 keV peak allowed to obtain the value Eexc = 497.342(3) keV, which is the most precise to-date. This leads to the following Q* value for the decay 115In to 115Sn*: Q* = 147 +- 10 eV.

   nucl-exEPL(2018)·14 citations
3. 03*

   Electric dipole moment of light nuclei - 6Li, 7Li, 9Be, 11B, and 13C -

   Nodoka Yamanaka🇫🇷

   In this proceeding, we present the results of the theoretical evaluations of the electric dipole moment (EDM) of light nuclei, including the preliminary value for the 11B nucleus. From the data, we can infer an approximate counting rule, and predict the EDM of other light nuclei.

   ↳ nucl-thhep-exhep-phnucl-exHyperfine Interact.(2018)·6 citations
4. 04*

   Multiple chiral doublets in four-$j$ shells particle rotor model: five possible chiral doublets in ${}_{60}^{136}$Nd${}_{76}$

   Q. B. Chen🇩🇪 · B. F. Lv🇫🇷 · C. M. Petrache🇫🇷 · J. Meng🇨🇳

   A particle rotor model, which couples nucleons in four single-$j$ shells to a triaxial rotor core, is developed to investigate the five pairs of nearly degenerate doublet bands recently reported in the even-even nucleus ${}^{136}$Nd. The experimental energy spectra and available $B(M1)/B(E2)$ values are successfully reproduced. The angular momentum geometries of the valence nucleons and the core support the chiral rotation interpretations not only for the previously reported chiral doublet, but also for the other four candidates. Hence, ${}^{136}$Nd is the first even-even candidate nucleus in which the multiple chiral doublets exist. Five pairs of chiral doublet bands in a single nucleus is also a new record in the study of nuclear chirality.

   ↳ nucl-thnucl-exPLB(2018)·60 citations
5. 05*

   New Perspective on Hybrid Mesons

   Shu-Sheng Xu🇨🇳 · Zhu-Fang Cui🇨🇳 · Lei Chang🇨🇳 · Joannis Papavassiliou🇪🇸 · Craig D. Roberts🇺🇸 · Hong-Shi Zong🇨🇳

   It is thought that strong interactions within the Standard Model can generate bound-states in which non-Abelian gauge-bosons play a dual role, serving both as force and matter fields. In this context we introduce a novel approach to the hybrid-meson (valence-gluon+quark+antiquark) bound-state problem in relativistic quantum field theory. Exploiting the existence of strong two-body correlations in the gluon-quark, $q_g=[gq]$, and gluon-antiquark, ${\bar{q}}_g=[g\bar{q}]$ channels, we argue that a sound description of hybrid properties can be obtained by solving a coupled-pair of effectively two-body equations; and, consequently, that hybrids may be viewed as highly-correlated $q_g\bar{q}\leftrightarrow q{\bar{q}}_g$ bound-states. Analogies may be drawn between this picture of hybrid structure and that of baryons, in which quark+quark (diquark) correlations play a key role. The potential of this formulation is illustrated by calculating the spectrum of light-quark isovector hybrid mesons.

   ↳ nucl-thhep-exhep-lathep-ph+1EPJA(2019)·33 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.