Tue·Jul 10, 2018Tuesday·July 10, 2018

1. 01*

   Validation of Geant4's G4NRF module against nuclear resonance fluorescence data from ${}^{238}$U and ${}^{27}$Al

   Jayson R Vavrek · Brian S Henderson🇺🇸 · Areg Danagoulian

   G4NRF is a simulation module for modeling nuclear resonance fluorescence (NRF) interactions in the Geant4 framework. In this work, we validate G4NRF against both absolute and relative measurements of three NRF interactions near 2.2 MeV in ${}^{238}$U and ${}^{27}$Al using the transmission NRF data from the experiments described in arXiv:1712.02904. Agreement between the absolute NRF count rates observed in the data and predicted by extensive Geant4+G4NRF modeling validate the combined Geant4+G4NRF to within $15$--$20\%$ in the ${}^{238}$U NRF transitions and $8\%$ in ${}^{27}$Al, for an average $13\%$ discrepancy across the entire study. The difference between simulation and experiment in relative NRF rates, as expressed as ratios of count rates in various NRF lines, is found at the level of $\lesssim 4\%$, and is statistically identical to zero. Inverting the analysis, approximate values of the absolute level widths and branching ratios for ${}^{238}$U and ${}^{27}$Al are also obtained.

   nucl-exphysics.ins-detNucl.Instrum.Meth.B(2019)·4 citations
2. 02*

   ALICE measurements of flow coefficients and their correlations in small (pp and p-Pb) and large (Xe-Xe and Pb-Pb) collision systems

   Katarína Gajdošová (for the ALICE Collaboration)🇩🇰

   Many observables which are used as a signature of the collective effects in heavy-ion collisions when measured in high multiplicity pp and pA interactions reveal a very similar behaviour. We will present first measurements of different order flow coefficients and their magnitude correlations for data collected by ALICE during the LHC Run 2 operation, which includes pp collisions at $\sqrt{s}=13$ TeV, p-Pb at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV, Xe-Xe at $\sqrt{s_{\mathrm{NN}}}=5.44$ TeV and Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV. Such a broad spectrum of colliding systems with different energies and wide range of multiplicity allow for detailed investigation of their collision dynamics. The measurements are based on a newly developed subevent technique, which was proven to be particularly important for studies in small systems. The results provide an important insight into the nature of collective phenomena in different collision systems.

   nucl-exNPA(2019)·11 citations
3. 03*

   Density Functional Theory (DFT) for atomic nuclei: a simple introduction

   G. Colò🇮🇹

   The present contribution does not aim at replacing the huge and often excellent literature on DFT for atomic nuclei, but tries to provide an updated introduction to this topic. The goal would be, ideally, to help a fresh M.Sc. or Ph.D. student (or a researcher from other fields) to become acquainted with some basic concepts, and then move to the specialized textbooks or papers with some ability for orienteering. We first introduce the basics of DFT, and show the difference with the "naive" mean-field theory, that is doomed to fail as a model even in the simple case of uniform nuclear matter. We introduce the Energy Density Functionals (EDFs) that are used in nuclear structure, with few examples of their applications. The concepts of symmetry breaking and restoration are briefly discussed. We also include an introduction to the time-dependent extension of DFT that, so far, has been implemented essentially only in the adiabatic approximation and has been applied mainly to the study of nuclear vibrations. With this material, we hope that any reader is able to deal with the texts that go deeper into each of the topics, having understood that DFT is probably the best compromise in nuclear structure theory between simplicity, accuracy, and broad range of applicability.

   ↳ nucl-thcond-mat.othernucl-ex1 citation
4. 04*

   Review of (anti-)Nuclei Production from High Energy Experiments

   Natasha Sharma🇮🇳

   An overview of nuclei and anti-nuclei production with results from different experiments are discussed. The comparison of data with the thermal and coalescence models is also discussed to understand their production mechanisms in high energy collisions.

   ↳ hep-exnucl-exSpringer Proc.Phys.(2018)·1 citation
5. 05*

   The role of angle dependent phase rotations of reaction amplitudes in $\eta$ photoproduction on protons

   A. Švarc · H. Osmanović · M. Hadžimehmedović · R. Omerović · J. Stahov · V. Kashevarov · K. Nikonov · M. Ostrick · L. Tiator

   It has recently been proven that the invariance of observables with respect to angle dependent phase rotations of reaction amplitudes mixes multipoles changing also their relative strength [1]. All contemporary partial wave analyses (PWA) in $\eta$ photoproduction on protons, either energy dependent (ED) [2-5] or single energy (SE) [6] do not take this effect into consideration. It is commonly accepted that there exist quite some similarity in the $E0+$ multipole for all PWA, but notable differences in this, but also in remaining partial waves still remain. In this paper we demonstrate that once this phase rotations are properly taken into account, all contemporary ED and SE partial wave analysis become almost identical for the dominant $E0+$ multipole, and the agreement among all other multipoles becomes much better. We also show that the the measured observables are almost equally well reproduced for all PWA, and the remaining differences among multipoles can be attributed solely to the difference of predictions for unmeasured observables. So, new measurements are needed.

   ↳ nucl-thnucl-exPRC(2018)·4 citations
6. 06*

   Few- and many-nucleon systems with semilocal coordinate-space regularized chiral two- and three-body forces

   E. Epelbaum🇩🇪 · J. Golak🇵🇱 · K. Hebeler🇩🇪 · T. Hüther🇩🇪 · H. Kamada🇯🇵 · H. Krebs🇩🇪 · P. Maris🇺🇸 · U.-G. Meißner🇩🇪 · A. Nogga🇩🇪 · R. Roth🇩🇪 · R. Skibiński🇵🇱 · K. Topolnicki🇵🇱 and 3 other authors

   We present a complete calculation of nucleon-deuteron scattering as well as ground and low-lying excited states of light nuclei in the mass range A=3-16 up through next-to-next-to-leading order in chiral effective field theory using semilocal coordinate-space regularized two- and three-nucleon forces. It is shown that both of the low-energy constants entering the three-nucleon force at this order can be reliably determined from the triton binding energy and the differential cross section minimum in elastic nucleon-deuteron scattering. The inclusion of the three-nucleon force is found to improve the agreement with the data for most of the considered observables.

   ↳ nucl-thnucl-exPRC(2019)·113 citations
7. 07*

   Odderon and proton substructure from a model-independent Levy imaging of elastic $pp$ and $p\bar{p}$ collisions

   T. Csorgo🇭🇺 · R. Pasechnik🇸🇪 · A. Ster🇭🇺

   We describe a new and model-independent Lévy imaging method of quality fits to the published datasets and reconstruct the amplitude of high-energy $pp$ and $p\bar{p}$ elastic scattering processes. This method allows us to determine the excitation function of the shadow profile $P(b)$, the elastic slope $B(t)$ and the nuclear phase $\varphi (t)$ functions of $pp$ and $p\bar{p}$ collisions directly from the data. Surprisingly, notable qualitative differences in $B(t)$ for $pp$ and for $p\bar{p}$ collisions point towards an Odderon effect. As a by-product, we clearly identify the proton substructure with two different sizes at the ISR and LHC energies, that has striking similarity to a dressed quark (at the ISR) and a dressed diquark (at the LHC). We present model-independent results for the corresponding sizes and cross-sections for such a substructure for the existing data at different energies.

   ↳ hep-phhep-exnucl-exphysics.data-anEPJC(2019)·56 citations
8. 08*

   Heavy-flavor flow-harmonics in high-energy nuclear collisions: time-development and eccentricity fluctuations

   A. Beraudo🇮🇹 · A. De Pace🇮🇹 · M. Monteno🇮🇹 · M. Nardi🇮🇹 · F. Prino🇮🇹

   We study the development of heavy-flavor flow harmonics in high-energy nuclear collisions. The elliptic and triangular flow of heavy-flavor hadrons, arising from the finite impact parameter of the two nuclei and from event-by-event fluctuations of the initial geometry, is analyzed in detail, considering the contribution from particles decoupling from the fireball at various times. We also study the dependence of the flow harmonics on the event-shape fluctuations, considering events belonging to the same centrality class but characterized by very different eccentricities (or vice-versa).

   ↳ hep-phnucl-exnucl-thNPA(2019)·5 citations
9. 09*

   On strangeness in NA61/SHINE

   Maciej P. Lewicki (for the NA61/SHINE Collaboration)🇵🇱

   NA61/SHINE is a fixed target experiment at the CERN Super-Proton- Synchrotron. The main goals of the experiment are to discover the critical point of strongly interacting matter and to study the properties of the onset of deconfinement. In order to reach these goals, a study of hadron production properties is performed in nucleus-nucleus, proton-proton and proton-nucleus interactions as a function of collision energy and size of the colliding nuclei. In this paper, I will review recent results on strangeness production in p+p, Be+Be and Ar+Sc collisions in the SPS energy range. Kinematic spectra and mean multiplicities of kaons obtained with various analysis methods will be shown. An overview of strangeness production and its dependence on system size in the vicinity of the phase transition will be presented as well.

   ↳ hep-exhep-phnucl-exnucl-thActa Phys.Polon.Supp.(2018)·2 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.