Thu·Sep 21, 2017Thursday·September 21, 2017

1. 01*

   Structure of the neutron mid-shell nuclei ${}_{47}^{111,113}$Ag${}_{64,66}$

   S. Lalkovski🇧🇬 · E. A. Stefanova🇧🇬 · S. Kisyov🇷🇴 · A. Korichi🇫🇷 · D. Bazzacco🇮🇹 · M. Bergström🇩🇰 · A. Görgen🇳🇴 · B. Herskind🇩🇰 · H. Hübel🇩🇪 · A. Jansen🇩🇪 · T.L. Khoo🇺🇸 · T. Kutsarova🇧🇬 and 5 other authors

   ${}^{111}$Ag and ${}^{113}$Ag were produced in induced fission reaction, where yrast and near-yrast states were populated. To interpret the new data the Interacting Boson-Fermion model was used. A good agreement with the experimental data is achieved, suggesting that the two Ag nuclei have a well developed collectivity, superimposed on $\pi g_{9/2}^{-3}$ excitations previously observed throughout the entire isotopic chain.

   nucl-exPRC(2017)·8 citations
2. 02*

   Search for collectivity with azimuthal J/$\psi$-hadron correlations in high multiplicity p-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 and 8.16 TeV

   ALICE Collaboration

   We present a measurement of azimuthal correlations between inclusive J/$\psi$ and charged hadrons in p-Pb collisions recorded with the ALICE detector at the CERN LHC. The J/$\psi$ are reconstructed at forward (p-going, 2.03 $<$ y $<$ 3.53) and backward (Pb-going, $-$4.46 $<$ y $<$ $-$2.96) rapidity via their ${\mu }^{+}{\mu }^{-}$ decay channel, while the charged hadrons are reconstructed at mid-rapidity ($|\eta |$ $<$ 1.8). The correlations are expressed in terms of associated charged-hadron yields per J/$\psi$ trigger. A rapidity gap of at least 1.5 units is required between the trigger J/$\psi$ and the associated charged hadrons. Possible correlations due to collective effects are assessed by subtracting the associated per-trigger yields in the low-multiplicity collisions from those in the high-multiplicity collisions. After the subtraction, we observe a strong indication of remaining symmetric structures at $\Delta \phi$ $\approx$ 0 and $\Delta \phi$ $\approx$ $\pi$, similar to those previously found in two-particle correlations at middle and forward rapidity. The corresponding second-order Fourier coefficient ($v_2$) in the transverse momentum interval between 3 and 6 GeV/$c$ is found to be positive with a significance of about 5$\sigma$. The obtained results are similar to the J/$\psi$ $v_2$ coefficients measured in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV, suggesting a common mechanism at the origin of the J/$\psi$ $v_2$.

   nucl-exhep-exPLB(2018)·89 citations
3. 03*

   Electromagnetic Strength Distributions from the Ab Initio No-Core Shell Model

   Christina Stumpf · Tobias Wolfgruber · Robert Roth🇩🇪

   We present an ab initio approach for the description of collective excitations and transition strength distributions of arbitrary nuclei up into the sd-shell that based on the No-Core Shell Model in combination with the Lanczos strength-function method. Starting from two- and three-nucleon interactions from chiral effective field theory, we investigate the electric monopole, dipole, and quadrupole response of the even oxygen isotopes from 16-O to 24-O. The method describes the full energy range from low-lying excitations to the giant resonance region and beyond in a unified and consistent framework, including a complete description of fragmentation and fine-structure. This opens unique opportunities for understanding dynamic properties of nuclei from first principles and to further constrain nuclear interactions. We demonstrate the computational efficiency and the robust model-space convergence of our approach and compare to established approximate methods, such as the Random Phase Approximation, shedding new light on their deficiencies.

   ↳ nucl-thnucl-ex12 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.