Tue·Mar 7, 2017Tuesday·March 7, 2017

1. 01*

   Structure of 10N in 9C+p resonance scattering

   J. Hooker🇺🇸 · G.V. Rogachev🇺🇸 · V.Z. Goldberg🇺🇸 · E. Koshchiy🇺🇸 · B.T. Roeder🇺🇸 · H. Jayatissa🇺🇸 · C. Hunt🇺🇸 · C. Magana🇺🇸 · S. Upadhyayula🇺🇸 · E. Uberseder🇺🇸 · A. Saastamoinen🇺🇸

   The structure of exotic nucleus 10N was studied using 9C+p resonance scattering. Two L=0 resonances were found to be the lowest states in 10N. The ground state of 10N is unbound with respect to proton decay by 2.2(2) or 1.9(2) MeV depending on the 2- or 1- spin-parity assignment, and the first excited state is unbound by 2.8(2) MeV.

   nucl-exPLB(2017)·18 citations
2. 02*

   Signature of clustering in quantum many body systems probed by the giant dipole resonance

   Deepak Pandit🇮🇳 · Debasish Mondal🇮🇳 · Balaram Dey🇮🇳 · Srijit Bhattacharya🇮🇳 · S. Mukhopadhyay🇮🇳 · Surajit Pal🇮🇳 · A. De🇮🇳 · S. R. Banerjee🇮🇳

   The present experimental study illustrates how large deformations attained by nuclei due to cluster formation are perceived through the giant dipole resonance (GDR) strength function. The high energy GDR $\gamma$-rays have been measured from ${}^{32}$S at different angular momenta ($J$) but similar temperatures in the reactions ${}^4$He(E${}_{lab}$=45MeV) + ${}^{28}$Si and ${}^{20}$Ne(E${}_{lab}$=145MeV) + ${}^{12}$C. The experimental data at lower J ($\sim$ 10$\hslash$) suggests a normal deformation, similar to the ground state value, showing no potential signature of clustering. However, it is found that the GDR lineshape is fragmented into two prominent peaks at high J ($\sim$ 20$\hslash$) providing a direct measurement of the large deformation developed in the nucleus. The observed lineshape is also completely different from the ones seen for Jacobi shape transition at high $J$ pointing towards the formation of cluster structure in super-deformed states of ${}^{32}$S at such high spin. Thus, the GDR can be regarded as a unique tool to study cluster formation at high excitation energies and angular momenta.

   nucl-exPRC(2017)·11 citations
3. 03*

   High-Resolution Laser Spectroscopy of Long-Lived Plutonium Isotopes

   A. Voss🇫🇮 · V. Sonnenschein🇫🇮 · P. Campbell🇬🇧 · B. Cheal🇬🇧 · T. Kron · I.D. Moore🇫🇮 · I. Pohjalainen🇫🇮 · S. Raeder🇨🇦 · N. Trautmann🇩🇪 · K. Wendt🇩🇪

   Long-lived isotopes of plutonium were studied using two complementary techniques, high-resolution resonance ionisation spectroscopy (HR-RIS) and collinear laser spectroscopy (CLS). Isotope shifts have been measured on the $5f^{6}7s^2{}^7{F}_0\to 5f^{5}6d^{2}7s(J=1)$ and $5f^{6}7s^2{}^7{F}_1\to 5f^{6}7s7p(J=2)$ atomic transitions using the HR-RIS method and the hyperfine factors have been extracted for the odd mass nuclei ${}^{239,241}$Pu. Collinear laser spectroscopy was performed on the $5f^{6}7s{}^8{F}_{1/2}\to J=1/2(27523.61{\text{cm}}^{-1})$ ionic transition with the hyperfine $A$ factors measured for ${}^{239}$Pu. Changes in mean-squared charge radii have been extracted and show a good agreement with previous non-optical methods, with an uncertainty improvement by approximately one order of magnitude. Plutonium represents the heaviest element studied to date using collinear laser spectroscopy.

   nucl-exphysics.atom-phPRA(2017)·12 citations
4. 04*

   Determination of N* amplitudes from associated strangeness production in p+p collisions

   R. Münzer · L. Fabbietti · E. Epple · P. Klose · F. Hauenstein · N. Herrmann · D. Grzonka · Y. Leifels · M. Maggiora · D. Pleiner · B. Ramstein · J. Ritman and 56 other authors

   We present the first determination of the energy-dependent production amplitudes of N${}^{\ast }$ resonances with masses between 1650 MeV/c${}^2$ and 1900 MeV/c${}^2$ for an excess energy between $0$ and $600$ MeV. A combined Partial Wave Analysis of seven exclusively reconstructed data samples for the reaction p+p $\to pK\Lambda$ measured by the COSY-TOF, DISTO, FOPI and HADES collaborations in fixed target experiments at kinetic energies between 2.14 and 3.5 GeV is used to determine the amplitude of the resonant and non-resonant contributions.

   nucl-exPLB(2018)·21 citations
5. 05*

   Quantum Nuclear Pasta and Nuclear Symmetry Energy

   F. J. Fattoyev🇺🇸 · C. J. Horowitz🇺🇸 · B. Schuetrumpf🇩🇪

   Complex and exotic nuclear geometries are expected to appear naturally in dense nuclear matter found in the crust of neutron stars and supernovae environment collectively referred to as nuclear pasta. The pasta geometries depend on the average baryon density, proton fraction and temperature and are critically important in the determination of many transport properties of matter in supernovae and the crust of neutron stars. Using a set of self-consistent microscopic nuclear energy density functionals we present the first results of large scale quantum simulations of pasta phases at baryon densities $0.03\le \rho \le 0.10$ fm${}^{-3}$, proton fractions $0.05\le Y_p\le 0.40$, and zero temperature. The full quantum simulations, in particular, allow us to thoroughly investigate the role and impact of the nuclear symmetry energy on pasta configurations. We use the Sky3D code that solves the Skyrme Hartree-Fock equations on a three-dimensional Cartesian grid. For the nuclear interaction we use the state of the art UNEDF1 parametrization, which was introduced to study largely deformed nuclei, hence is suitable for studies of the nuclear pasta. Density dependence of the nuclear symmetry energy is simulated by tuning two purely isovector observables that are insensitive to the current available experimental data. We find that a minimum total number of nucleons $A=2000$ is necessary to prevent the results from containing spurious shell effects and to minimize finite size effects. We find that a variety of nuclear pasta geometries are present in the neutron star crust and the result strongly depends on the nuclear symmetry energy. The impact of the nuclear symmetry energy is less pronounced as the proton fractions increase. Quantum nuclear pasta calculations at $T=0$ MeV are shown to get easily trapped in meta-stable states, and possible remedies to avoid meta-stable solutions are discussed.

   ↳ nucl-thastro-ph.SRnucl-exphysics.comp-phPRC(2017)·69 citations
6. 06*

   Charmonium ground and excited states at finite temperature from complex Borel sum rules

   Ken-Ji Araki🇯🇵 · Kei Suzuki🇯🇵 · Philipp Gubler🇰🇷 · Makoto Oka🇯🇵

   Charmonium spectral functions in vector and pseudoscalar channels at finite temperature are investigated through the complex Borel sum rules and the maximum entropy method. Our approach enables us to extract the peaks corresponding to the excited charmonia, ${\psi }^{\prime }$ and ${\eta }_c^{\prime }$, as well as those of the ground states, $J/\psi$ and ${\eta }_c$, which has never been achieved in usual QCD sum rule analyses. We show the spectral functions in vacuum and their thermal modification around the critical temperature, which leads to the almost simultaneous melting (or peak disappearance) of the ground and excited states.

   ↳ hep-phhep-latnucl-exnucl-thPLB(2018)·6 citations
7. 07*

   The first result on 76Ge neutrinoless double beta decay from CDEX-1 experiment

   Li Wang · Qian Yue · KeJun Kang · JianPing Cheng · YuanJing Li · TszKing Henry Wong · ShinTed Lin · JianPing Chang · JingHan Chen · QingHao Chen · YunHua Chen · Zhi Deng and 61 other authors

   We report the first result on Ge-76 neutrinoless double beta decay from CDEX-1 experiment at China Jinping Underground Laboratory. A mass of 994 g p-type point-contact high purity germanium detector has been installed to search the neutrinoless double beta decay events, as well as to directly detect dark matter particles. An exposure of 304 kg*day has been analyzed. The wideband spectrum from 500 keV to 3 MeV was obtained and the average event rate at the 2.039 MeV energy range is about 0.012 count per keV per kg per day. The half-life of Ge-76 neutrinoless double beta decay has been derived based on this result as: T 1/2 > 6.4*10^22 yr (90% C.L.). An upper limit on the effective Majorana-neutrino mass of 5.0 eV has been achieved. The possible methods to further decrease the background level have been discussed and will be pursued in the next stage of CDEX experiment.

   ↳ hep-exnucl-exphysics.ins-detSCPMA(2017)·26 citations
8. 08*

   Determining the neutrino mass with Cyclotron Radiation Emission Spectroscopy - Project 8

   Ali Ashtari Esfahani🇺🇸 · David M. Asner🇺🇸 · Sebastian Böser🇩🇪 · Raphael Cervantes🇺🇸 · Christine Claessens🇩🇪 · Luiz de Viveiros🇺🇸 · Peter J. Doe🇺🇸 · Shepard Doeleman🇺🇸 · Justin L. Fernandes🇺🇸 · Martin Fertl🇺🇸 · Erin C. Finn🇺🇸 · Joseph A. Formaggio🇺🇸 and 32 other authors

   The most sensitive direct method to establish the absolute neutrino mass is observation of the endpoint of the tritium beta-decay spectrum. Cyclotron Radiation Emission Spectroscopy (CRES) is a precision spectrographic technique that can probe much of the unexplored neutrino mass range with $\mathcal{O}(\mathrm{eV})$ resolution. A lower bound of $m({\nu }_e)\gtrsim 9(0.1)\mathrm{meV}$ is set by observations of neutrino oscillations, while the KATRIN Experiment - the current-generation tritium beta-decay experiment that is based on Magnetic Adiabatic Collimation with an Electrostatic (MAC-E) filter - will achieve a sensitivity of $m({\nu }_e)\lesssim 0.2\mathrm{eV}$. The CRES technique aims to avoid the difficulties in scaling up a MAC-E filter-based experiment to achieve a lower mass sensitivity. In this paper we review the current status of the CRES technique and describe Project 8, a phased absolute neutrino mass experiment that has the potential to reach sensitivities down to $m({\nu }_e)\lesssim 40\mathrm{meV}$ using an atomic tritium source.

   ↳ physics.ins-dethep-exnucl-exJ.Phys.G(2017)·203 citations
9. 09*

   Transverse Momentum Spectra and Nuclear Modification Factor using Boltzmann Transport Equation with Flow in Pb+Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV

   Sushanta Tripathy🇮🇳 · Arvind Khuntia🇮🇳 · Swatantra Kumar Tiwari🇮🇳 · Raghunath Sahoo🇮🇳

   In the continuation of our previous work, the transverse momentum ($p_T$) spectra and nuclear modification factor ($R_{AA}$) are derived using relaxation time approximation of Boltzmann Transport Equation (BTE). The initial $p_T$-distribution used to describe $p+p$ collisions has been studied with the pQCD inspired power-law distribution, the Hagedorn's empirical formula and with the Tsallis non-extensive statistical distribution. The non-extensive Tsallis distribution is observed to describe the complete range of the transverse momentum spectra. The Boltzmann-Gibbs Blast Wave (BGBW) distribution is used as the equilibrium distribution in the present formalism, to describe the $p_T$-distribution and nuclear modification factor in nucleus-nucleus collisions. The experimental data for Pb+Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV at the Large Hadron Collider at CERN have been analyzed for pions, kaons, protons, $K^{\ast 0}$ and $\varphi$. It is observed that the present formalism while explaining the transverse momentum spectra upto 5 GeV/c, explains the nuclear modification factor very well upto 8 GeV/c in $p_T$ for all these particles except for protons. $R_{AA}$ is found to be independent of the degree of non-extensivity, $q_{pp}$ after $p_T\sim$ 8 GeV/c.

   ↳ nucl-thhep-phnucl-exEPJA(2017)·22 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.