Tue·Mar 29, 2016Tuesday·March 29, 2016

1. 01*

   The mutable nature of particle-core excitations with spin in the one-valence-proton nucleus 133Sb

   G. Bocchi🇮🇹 · S. Leoni🇮🇹 · B. Fornal🇵🇱 · G. Colo'🇮🇹 · P.F. Bortignon🇮🇹 · S. Bottoni🇮🇹 · A. Bracco🇮🇹 · C. Michelagnoli🇫🇷 · D. Bazzacco🇮🇹 · A. Blanc🇫🇷 · G. De France🇫🇷 · M. Jentschel🇫🇷 and 34 other authors

   The gamma-ray decay of excited states of the one-valence-proton nucleus 133Sb has been studied using cold-neutron induced fission of 235U and 241Pu targets, during the EXILL campaign at the ILL reactor in Grenoble. By using a highly efficient HPGe array, coincidences between gamma-rays prompt with the fission event and those delayed up to several tens of microseconds were investigated, allowing to observe, for the first time, high-spin excited states above the 16.6 micros isomer. Lifetimes analysis, performed by fast-timing techniques with LaBr3(Ce) scintillators, reveals a difference of almost two orders of magnitude in B(M1) strength for transitions between positive-parity medium-spin yrast states. The data are interpreted by a newly developed microscopic model which takes into account couplings between core excitations (both collective and non-collective) of the doubly magic nucleus 132Sn and the valence proton, using the Skyrme effective interaction in a consistent way. The results point to a fast change in the nature of particle-core excitations with increasing spin.

   nucl-exnucl-thPLB(2016)·33 citations
2. 02*

   Transverse wobbling motion in ${}^{134}$Ce and ${}^{136}$Nd

   C. M. Petrache🇫🇷 · S. Guo🇫🇷

   The existence of one-phonon and possible two-phonon transverse wobbling bands is proposed for the first time in two even-even nuclei, ${}^{134}$Ce and ${}^{136}$Nd. The predominant $E2$ character of the $\Delta I=1$ transitions connecting the one-phonon wobbling band in ${}^{134}$Ce to the two-quasiparticle yrast band supports the wobbling interpretation. The extracted wobbling frequencies decrease with increasing spin, indicating the transverse character of the wobbling motion, with the angular momenta of the two quasiparticles aligned perpendicular to the axis of collective rotation. A candidate for two-phonon wobbling motion is also proposed in ${}^{136}$Nd. The wobbling frequencies calculated in the harmonic frozen approximation are in good agreement with the experimental ones for both the${}^{134}$Ce and ${}^{136}$Nd nuclei.

   nucl-exnucl-th4 citations
3. 03*

   Cerenkov light identification with Si low-temperature detectors with Neganov-Luke effect-enhanced sensitivity

   L. Gironi🇮🇹 · M. Biassoni🇮🇹 · C. Brofferio🇮🇹 · S. Capelli🇮🇹 · P. Carniti🇮🇹 · L. Cassina🇮🇹 · M. Clemenza🇮🇹 · O. Cremonesi🇮🇹 · M. Faverzani🇮🇹 · E. Ferri🇮🇹 · E. Fossati🇮🇹 · A. Giachero🇮🇹 and 13 other authors

   A new generation of cryogenic light detectors exploiting Neganov-Luke effect to enhance the thermal signal has been used to detect the Cherenkov light emitted by the electrons interacting in TeO${}_2$ crystals. With this mechanism a high significance event-by-event discrimination between alpha and beta/gamma interactions at the ${}^{130}$Te neutrino-less double beta decay Q-value - (2527.515 $\pm$ 0.013) keV - has been demonstrated. This measurement opens the possibility of drastically reducing the background in cryogenic experiments based on TeO${}_2$.

   ↳ physics.ins-detnucl-exPRC(2016)·23 citations
4. 04*

   Understanding transport simulations of heavy-ion collisions at 100 and 400 AMeV: Comparison of heavy ion transport codes under controlled conditions

   Jun Xu🇨🇳 · Lie-Wen Chen🇨🇳 · ManYee Betty Tsang🇺🇸 · Hermann Wolter🇩🇪 · Ying-Xun Zhang🇨🇳 · Joerg Aichelin🇫🇷 · Maria Colonna🇮🇹 · Dan Cozma🇷🇴 · Pawel Danielewicz🇺🇸 · Zhao-Qing Feng🇨🇳 · Arnaud Le Fevre🇩🇪 · Theodoros Gaitanos🇬🇷 and 19 other authors

   Transport simulations are very valuable for extracting physics information from heavy-ion collision experiments. With the emergence of many different transport codes in recent years, it becomes important to estimate their robustness in extracting physics information from experiments. We report on the results of a transport code comparison project. 18 commonly used transport codes were included in this comparison: 9 Boltzmann-Uehling-Uhlenbeck-type codes and 9 Quantum-Molecular-Dynamics-type codes. These codes have been required to simulate Au+Au collisions using the same physics input for mean fields and for in-medium nucleon-nucleon cross sections, as well as the same initialization set-up, the impact parameter, and other calculational parameters at 100 and 400 AMeV incident energy. Among the codes we compare one-body observables such as rapidity and transverse flow distributions. We also monitor non-observables such as the initialization of the internal states of colliding nuclei and their stability, the collision rates and the Pauli blocking. We find that not completely identical initializations constitute partly for different evolutions. Different strategies to determine the collision probabilities, and to enforce the Pauli blocking, also produce considerably different results. There is a substantial spread in the predictions for the observables, which is much smaller at the higher incident energy. We quantify the uncertainties in the collective flow resulting from the simulation alone as about $30\%$ at 100 AMeV and $13\%$ at 400 AMeV, respectively. We propose further steps within the code comparison project to test the different aspects of transport simulations in a box calculation of infinite nuclear matter. This should, in particular, improve the robustness of transport model predictions at lower incident energies where abundant amounts of data are available.

   ↳ nucl-thnucl-exPRC(2016)·186 citations
5. 05*

   Exploring Dense and Cold QCD in Magnetic Fields

   E. J. Ferrer🇺🇸 · V. de la Incera🇺🇸

   Strong magnetic fields are commonly generated in off-central relativistic heavy-ion collisions in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Lab and in the Large Hadron Collider at CERN and have been used to probe the topological configurations of the QCD vacua. A strong magnetic field can affect the character and location of the QCD critical point, influence the QCD phases, and lead to anomalous transport of charge. To take advantage of the magnetic field as a probe of QCD at higher baryon densities, we are going to need experiments capable to scan the lower energy region. In this context, the nuclotron-based ion collider facility (NICA) at JINR offers a unique opportunity to explore such a region and complement alternative programs at RHIC and other facilities. In this paper we discuss some relevant problems of the interplay between QCD and magnetic fields and the important role the experiments at NICA can play in tackling them.

   ↳ nucl-thhep-phnucl-exEPJA(2016)·17 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.