Tue·Apr 25, 2017Tuesday·April 25, 2017

1. 01*

   Charge asymmetry dependence of anisotropic flow in pPb and PbPb collisions with CMS experiment

   Sang Eon Park (on behalf of the CMS Collaboration)🇺🇸

   In nucleus-nucleus collisions, the linear dependence found for the elliptic flow harmonic of both positive or negative charged particles as a function of event charge asymmetry is predicted by the phenomenon known as the Chiral Magnetic Wave (CMW) due to its induced electric quadrupole moment. Here, the event charge asymmetry $A_{\mathrm{ch}}$ is defined as $\frac{N_{+}-N_{-}}{N_{+}+N_{-}}$, where $N_{+}$ and $N_{-}$ are the number of positive and negative charged particles, respectively. However, other scenarios are also possible and may provide alternative explanations for the experimental results. New measurements of elliptic ($v_2$) and triangular ($v_3$) flow for positive and negative charged particles as a function of $A_{\mathrm{ch}}$ in pPb and PbPb collisions at $\sqrt{s_{{}_{NN}}}=5.02\mathrm{TeV}$ are presented, using data collected by the CMS experiment during the LHC runs 1 and 2. The slopes and intercepts of the charged-dependent $v_n$ harmonics vs. $A_{\mathrm{ch}}$ are directly compared for pPb and PbPb collisions with similar charged-particle multiplicities, where a strong CMW effect is not expected in very high multiplicity pPb events. Moreover, a comparison is made of the slope parameters between $v_2$ and $v_3$ harmonics normalized by the inclusive charge particle $v_n$ in PbPb collisions as a function of centrality. These results provide a means to discriminate between the CMW and other scenarios such as local charge conservation as possible explanations for the observed charge dependent behavior.

   nucl-exNPA(2017)·4 citations
2. 02*

   Dilepton Production in p$+$p, Au$+$Au collisions at $\sqrt{s_{NN}}$ = 200 GeV and U$+$U collisions at $\sqrt{s_{NN}}$ = 193 GeV

   J. D. Brandenburg🇺🇸

   In this contribution we report $e^{+}{e}^{-}$ spectra with various invariant mass and p${}_T$ differentials in Au$+$Au collisions at $\sqrt{s_{NN}}$=200 GeV and U$+$U collisions at $\sqrt{s_{NN}}$=193 GeV. The structure of the t ($t\approx p_{\mathrm{T}}^2$) distributions of these mass regions will be shown and compared with the same distributions in ultra-peripheral collisions. Additionally, this contribution discusses first measurements of ${\mu }^{+}{\mu }^{-}$ invariant mass spectra from STAR's recently installed Muon Telescope Detector (MTD) in p$+$p and Au$+$Au collisions at $\sqrt{s_{NN}}$ = 200 GeV.

   nucl-exNPA(2017)·4 citations
3. 03*

   Probing non-linearity of higher order anisotropic flow in Pb--Pb collisions

   You Zhou (on behalf of the ALICE Collaboration)🇩🇰

   The second and the third order anisotropic flow, $V_2$ and $V_3$, are determined by the corresponding initial spatial anisotropy coefficients, ${\epsilon }_2$ and ${\epsilon }_3$, in the initial density distribution. On the contrary, the higher order anisotropic flow $V_n$ ($n>3$), in addition to their dependence on the same order initial anisotropy coefficient ${\epsilon }_n$, have a significant contribution from lower order initial anisotropy coefficients, which leads to mode-coupling effects. In this contribution, we present the investigations on linear and non-linear modes in higher order anisotropic flow ($V_4$, $V_5$ and $V_6$) in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=$ 2.76 TeV using the ALICE detector at the Large Hadron Collider (LHC). A significant contribution from a non-linear mode is observed. A new observable, the non-linear response coefficient, is measured as well. The comparison to theoretical calculations provides crucial information on dynamic of the created system especially at the freeze-out conditions, which are poorly known from previous flow measurements.

   nucl-exnucl-thNPA(2017)·1 citation
4. 04*

   Measurement of $D^{\ast }$-meson triggered correlations in p+p collisions at RHIC

   Long Ma🇨🇳

   We report the preliminary results of the azimuthal correlations between $D^{\ast \pm }$ mesons and charged hadrons ($D^{\ast }$-h) measured by the STAR experiment in proton+proton collisions at $\sqrt{s}$ = 500 GeV. Results at mid-rapidity in the transverse-momentum range 8 $\le$ $p_T^{D^{\ast }}$ $\le$ 20 GeV/$c$ are compared with light hadron triggered correlations (h-h) and PYTHIA predictions. We also present an exploratory study of azimuthal correlations between $D^{\ast +}$ and $D^{\ast -}$ mesons in p+p collisions. The prospects of measuring heavy-flavor triggered correlations in heavy-ion collisions at RHIC energies are also discussed.

   nucl-exNucl.Part.Phys.Proc.(2017)·4 citations
5. 05*

   2016 Update of the discovery of nuclides

   M. Thoennessen🇺🇸

   The 2016 update of the discovery of nuclide project is presented. Only twelve new nuclides were observed for the first time in 2016. A large number of isotopes is still only published in conference proceedings or internal reports. No changes to earlier assignments were made.

   nucl-exIJMPE(2017)·12 citations
6. 06*

   Charge redistribution from novel magneto-vorticity coupling in anomalous hydrodynamics

   Koichi Hattori🇨🇳 · Yi Yin🇺🇸

   We discuss new transport phenomena in the presence of both a strong magnetic field and a vortex field. Their interplay induces a charge distribution and a current along the magnetic field. We show that the associated transport coefficients can be obtained from a simple analysis of the single-particle distribution functions and also from the Kubo formula calculation. The consistent results from these analyses suggest that the transport coefficients are tied to the chiral anomaly in the (1+1) dimension because of the dimensional reduction in the lowest Landau levels.

   ↳ nucl-thhep-phnucl-exNPA(2017)·0 citations
7. 07*

   Annual modulation of dark matter: The ANAIS-112 case

   I. Coarasa🇪🇸 · J. Amaré🇪🇸 · S. Cebrián🇪🇸 · C. Cuesta🇪🇸 · E. García🇪🇸 · M. Martínez🇪🇸 · M. A. Oliván🇪🇸 · Y. Ortigoza🇪🇸 · A. Ortiz de Solórzano🇪🇸 · J. Puimedón🇪🇸 · M. L. Sarsa🇪🇸 · J. A. Villar🇪🇸 · P. Villar🇪🇸

   The annual modulation measured by the DAMA/LIBRA experiment can be explained by the interaction of dark matter WIMPs in NaI(Tl) scintillator detectors. Other experiments, with different targets or techniques, exclude the region of parameters singled out by DAMA/LIBRA, but the comparison of their results relies on several hypotheses regarding the dark matter model. ANAIS-112 is a dark matter search with 112.5 kg of NaI(Tl) scintillators under commissioning at the Canfranc Underground Laboratory (LSC) to test the DAMA/LIBRA result in a model independent way. We analyze its prospects in terms of the a priori critical and detection limits of the experiment. The analysis is based on the detector response and the background level measured for the first modules operated in Canfranc.

   ↳ astro-ph.IMnucl-exphysics.ins-det10 citations
8. 08*

   Two-particle multiplets splitting as a guideline in nucleon pairing estimations

   L.T. Imasheva (1) · B.S. Ishkhanov (1,2)🇷🇺 · S.V. Sidorov (1) · M.E. Stepanov (1) · T.Yu. Tretyakova (2) ((1) Department of Physics, Lomonosov Moscow State University, (2) Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University)

   The ground state multiplet structure for nuclei over the wide range of mass number $A$ was calculated in $\delta$-approximation and different mass relations for pairing energy was analysed in this work. Correlation between the calculated multiplet structure and experimental data offer a guideline in deciding between mass relations for nucleon pairing.

   ↳ nucl-thnucl-exPhys.Part.Nucl.(2017)·4 citations
9. 09*

   Low-energy $\eta$-nucleon interaction studied with $\eta$ photoproduction off the deuteron

   S. X. Nakamura (1, 2)🇯🇵 · H. Kamano (3,4)🇯🇵 · T. Ishikawa (5,6) ((1) Osaka Univ., (2) Univ. Cruzeiro do Sul, (3) KEK, (4) J-PARC, (5) ELPH, (6) Tohoku Univ.)🇯🇵

   We develop a reaction model for $\eta$ photoproduction off the deuteron ($\gamma d\to \eta pn$), and study the reaction at a special kinematics, where the photon beam energy is $\sim 0.94$ GeV and the scattered proton is detected at $\sim 0^{\circ }$, for the purpose of determining the $\eta$-nucleon scattering length ($a_{\eta N}$) and effective range ($r_{\eta N}$). In this kinematics, the $\eta$-nucleon elastic rescattering is significantly enhanced while other background mechanisms being suppressed. We show that a ratio $R$, the $\gamma d\to \eta pn$ cross section divided by the $\gamma p\to \eta p$ cross section convoluted with the proton momentum distribution in the deuteron, has a very good resolving power of $a_{\eta N}$ and $r_{\eta N}$. We conclude that the $R$ data with 5% error, binned in 1 MeV width of the $\eta$-neutron invariant mass, can determine $\mathrm{Re}[a_{\eta N}]$ ($\mathrm{Re}[r_{\eta N}]$) at the precision of $\sim \pm$0.1 fm ($\sim \pm$0.5 fm), significantly narrowing down the previously estimated ranges of the parameters. To arrive at the conclusion, it is essential to use the $\gamma d\to \eta pn$ reaction model equipped with elementary amplitudes that are well constrained by $\pi N$ and $\gamma N$ reaction data through a sophisticated coupled-channels analysis. This result strongly motivates the Research Center for Electron Photon Science (ELPH) at Tohoku University to measure $R$.

   ↳ nucl-thhep-exhep-phnucl-exPRC(2017)·16 citations
10. 10*

    Shape-phase transitions in odd-mass $\gamma$-soft nuclei with mass $A\approx 130$

    K. Nomura🇫🇷 · T. Nikšić🇭🇷 · D. Vretenar🇭🇷

    Quantum phase transitions between competing equilibrium shapes of nuclei with an odd number of nucleons are explored using a microscopic framework of nuclear energy density functionals and a particle-boson core coupling model. The boson Hamiltonian for the even-even core nucleus, as well as the spherical single-particle energies and occupation probabilities of unpaired nucleons, are completely determined by a constrained self-consistent mean-field calculation for a specific choice of the energy density functional and pairing interaction. Only the strength parameters of the particle-core coupling have to be adjusted to reproduce a few empirical low-energy spectroscopic properties of the corresponding odd-mass system. The model is applied to the odd-A Ba, Xe, La and Cs isotopes with mass $A\approx 130$, for which the corresponding even-even Ba and Xe nuclei present a typical case of $\gamma$-soft nuclear potential. The theoretical results reproduce the experimental low-energy excitation spectra and electromagnetic properties, and confirm that a phase transition between nearly spherical and $\gamma$-soft nuclear shapes occurs also in the odd-A systems.

    ↳ nucl-thnucl-exPRC(2017)·44 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.