Wed·Oct 11, 2017Wednesday·October 11, 2017

1. 01*

   Shape and Angular Distribution of the 4.438-MeV Line from Proton Inelastic Scattering off 12C

   J. Kiener🇫🇷

   The emission of the 4.438-MeV gamma-ray line in proton inelastic scattering off 12C has been investigated in detail. The correlated scattering and emission process is described independently for the direct reaction mechanism and for the compound-nucleus (CN) component. The inelastic scattering process for direct reactions is treated with a coupled-channels nuclear reaction code, while the CN component is described as a superposition of separate resonances with definite spin and parity, treated with the angular momentum coupling theory. The calculations are compared to a comprehensive data set on measured line shapes and angular distributions in the proton energy range E_p = 5.44 - 25.0 MeV. In the range E_p ~ 12 - 25 MeV a good agreement is obtained in calculations assuming direct reactions with only a negligible part of CN reactions. At lower energy, the data are reproduced by incoherent sums of the direct component with typically one CN resonance. Based on these results, the prospectives for line shape calculations applied to solar flares and gamma-ray emission in proton radiotherapy are discussed.

   nucl-exastro-ph.HENucl.Theor.(2017)·1 citation
2. 02*

   Reinvestigation of the excited states in the proton emitter ${}^{151}$Lu: particle-hole excitations across the $N=Z=64$ subshell

   F. Wang · B.H. Sun · Z. Liu · C. Qi · L.H. Zhu · C. Scholey · S.F. Ashley · L. Bianco · D.M. Cullen · I.J. Cullen · I.G. Darby · S. Eeckhaudt and 32 other authors

   The excited states of the proton emitter ${}^{151}$Lu were reinvestigated in a recoil-decay tagging experiment at the Accelerator Laboratory of the University of Jyväskylä (JYFL). The level scheme built on the ground state of ${}^{151}$Lu was updated with five new $\gamma$-ray transitions. Large-scale shell model calculations were carried out to interpret the experimental level scheme. It is found that the excitation energies of states above the $27/2^{-}$ and $23/2^{+}$ isomeric levels can be sensitive to excitations from $g_{7/2}$ and $d_{5/2}$ to single-particle orbitals above $N=Z=64$.

   nucl-exPRC(2017)·5 citations
3. 03*

   Causal Electric Charge Diffusion and Balance Functions in Relativistic Heavy Ion Collisions

   Joseph I. Kapusta🇺🇸 · Christopher Plumberg🇺🇸

   We study the propogation and diffusion of electric charge fluctuations in high energy heavy ion collisions using the Cattaneo form for the dissipative part of the electric current. As opposed to the ordinary diffusion equation this form limits the speed at which charge can propagate. Including the noise term in the current, which arises uniquely from the fluctuation-dissipation theorem, we calculate the balance functions for charged hadrons in a simple 1+1 dimensional Bjorken hydrodynamical model. Limiting the speed of propagation of charge fluctuations increases the height and reduces the width of these balance functions when plotted versus rapidity. We also estimate the numerical value of the associated diffusion time constant from AdS/CFT theory.

   ↳ nucl-thnucl-exPRC(2018)·35 citations
4. 04*

   Nuclear clustering and the electron screening puzzle

   C.A. Bertulani🇺🇸 · C. Spitaleri🇮🇹

   Electron screening changes appreciably the magnitude of astrophysical nuclear reactions within stars. This effect is also observed in laboratory experiments on Earth, where atomic electrons are present in the nuclear targets. Theoretical models were developed over the past 30 years and experimental measurements have been carried out to study electron screening in thermonuclear reactions. None of the theoretical models were able to explain the high values of the experimentally determined screening potentials. We explore the possibility that the "electron screening puzzle" is due to nuclear clusterization and polarization effects in the fusion reactions. We will discuss the supporting arguments for this scenario.

   ↳ nucl-thnucl-exEPJ Web Conf.(2017)·3 citations
5. 05*

   Measurements of vector meson photoproduction with ALICE in ultra-peripheral Pb-Pb collisions at $\sqrt{{\mathbf{s}}_{\mathrm{NN}}}=5.02$ TeV

   V. Pozdniakov (for the ALICE Collaboration)

   The intense photon fluxes of relativistic nuclei provide a possibility to study photonuclear and two-photon interactions in ultra-peripheral collisions (UPC) where the nuclei do not overlap and no strong nuclear interactions occur. The study of such collisions provides information about the initial state of nuclei. First ALICE results from the LHC Run 2 are presented for forward exclusive \jpsi production in UPC, which is sensitive to the gluon distribution in nuclei. The increased statistics and the higher collision energy allows for a more detailed study at lower values of Bjorken-$x$. The analysis of the $\gamma +A\to {\rho }^0+A$ process in UPC is a tool to test the so-called black disk regime, where the target nucleus appears like a black disk and the total ${\rho }^0+A$ cross section reaches its limit. ALICE reports new measurements of \rrho photoproduction cross sections in Pb-Pb UPC at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV at mid-rapidity, which are compared to predictions.

   ↳ hep-exnucl-exPoS(2017)·3 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.