Nuclear Theory·nucl-th

Thursday·April 6, 2017

9 papers—7 primary·2 cross-listed

01
On the charge distribution of $d^{*} (2380)$
Yubing Dong🇨🇳 · Fei Huang🇨🇳 · Pengnian Shen🇨🇳 · Zongye Zhang🇨🇳
We calculate the charge distributions of $d^{*} (2380)$ . Two different interpretations of the $d^{*}$ are considered for a comparison. One is a compact explanation with coupled $ΔΔ + C C$ two-channel approximation in the chiral constituent quark model. Another is a resonance state of $D_{12} π$ . The remarkable differences of the charge distributions in the two pictures are shown and it is expected that the future experiments may provide a clear test for the different theoretical interpretations.
nucl-thPRD(2017)·20 citations
02
Three-body nuclei and their astrophysical implications: the case of $^{6}$ He
J. Casal🇪🇸 · M. Rodríguez-Gallardo🇪🇸 · J. M. Arias🇪🇸
The analytic THO method is generalized to study three-body nuclei of astrophysical interest, and applied to $^{6}$ He. Results are consistent with previous publications and experimental data.
nucl-thAIP Conf.Proc.(2013)·2 citations
03
Reactions induced by $^{9}$ Be in a four-body continuum-discretized coupled-channels framework
J. Casal🇪🇸 · M. Rodríguez-Gallardo🇪🇸 · J. M. Arias🇪🇸
We investigate the elastic scattering of $^{9}$ Be on $^{208}$ Pb at beam energies above (50 MeV) and below (40 MeV) the Coulomb barrier. The reaction is described within a four-body framework using the Continuum-Discretized Coupled-Channels (CDCC) method. The $^{9}$ Be projectile states are generated using the analytical Transformed Harmonic Oscillator (THO) basis in hyperspherical coordinates. Our calculations confirm the importance of continuum effects at low energies.
nucl-thSpringer Proc.Phys.(2016)·0 citations
04
$^{9}$ Be scattering within a four-body continuum-discretized coupled-channels framework
J. Casal · M. Rodríguez-Gallardo · J. M. Arias
The scattering of $^{9}$ Be on $^{208}$ Pb is addressed within a four-body Continuum-Discretized Coupled-Channels (CDCC) framework, considering a three-body $α + α + n$ projectile plus a structureless target. The projectile states are generated using the analytical Transformed Harmonic Oscillator (THO) basis in hyperspherical coordinates. Both the elastic and breakup channels are described on the same footing. We find a good agreement between our calculations and the experimental data at beam energies around and below the Coulomb barrier.
nucl-thEPJ Web Conf.(2016)·0 citations
05
Global $Λ$ polarization in heavy-ion collisions from a transport model
Hui Li🇨🇳 · Long-Gang Pang🇩🇪 · Qun Wang🇨🇳 · Xiao-Liang Xia🇨🇳
The polarizations of $Λ$ and $Λ ˉ$ hyperons are important quantities in extracting the fluid vorticity of the strongly coupled quark gluon plasma and the magnitude of the magnetic field created in off-central heavy-ion collisions, through the spin-vorticity and spin-magnetic coupling. We computed the energy dependence of the global $Λ$ polarization in off-central Au+Au collisions in the energy range $s_{N N} = 7.7 - 200$ GeV using a multiphase transport model. The observed polarizations with two different impact parameters agree quantitatively with recent STAR measurements. The energy dependence of the global $Λ$ polarization is decomposed as energy dependence of the $Λ$ distribution at hadronization and the space-time distribution of the fluid-vorticity field. The visualization of both the $Λ$ distribution and the fluid-vorticity field show a smaller tilt at higher collisional energies, which indicates that the smaller global polarization at higher collisional energies is caused by a smaller angular momentum deposition at midrapidity.
nucl-thPRC(2017)·251 citations
06
Statistical moments in superposition models and strongly intensive measures
Wojciech Broniowski🇵🇱 · Adam Olszewski🇵🇱
First, we present a concise glossary of formulas for composition of standard, cumulant, factorial, and factorial cumulant moments in superposition (compound) models, where final particles are created via independent emission from a collection of sources. Explicit mathematical formulas for the composed moments are given to all orders. We discuss the composition laws for various types of moments via the generating-function methods and list the formulas for the unfolding of the unwanted fluctuations. Second, the technique is applied to the difference of the scaled multiplicities of two particle types. This allows us for a systematic derivation and a simple algebraic interpretation of the so-called strongly intensive fluctuation measures. With the help of the formalism we obtain several new strongly intensive measures involving higher-rank moments. The reviewed as well as the new results may be useful in investigations of mechanisms of particle production and event-by-event fluctuations in high-energy nuclear and hadronic collisions, and in particular in the search for signatures of the QCD phase transition at a finite baryon density.
nucl-thnucl-exPRC(2017)·12 citations
07
Density dependence of 2p-2h meson-exchange currents
J.E. Amaro🇪🇸 · M.B. Barbaro🇮🇹 · J.A. Caballero🇪🇸 · A. De Pace🇮🇹 · T.W. Donnelly🇺🇸 · G.D. Megias🇪🇸 · I. Ruiz Simo🇪🇸
We analyze the density dependence of the contribution of meson-exchange currents to the lepton-nucleus inclusive cross section in the two-particle two-hole channel. The model is based on the Relativistic Fermi Gas, where each nucleus is characterized by its Fermi momentum $k_{F}$ . We find that the 2p-2h nuclear response functions at their peaks scale as $A k_{F}^{2}$ for Fermi momentum going from 200 to 300 MeV/c and momentum transfer $q$ from $2 k_{F}$ to 2 GeV/c. This behavior is different from what is found for the quasielastic response, which scales as $A / k_{F}$ . Additionally, the deep scaling region is also discussed and there the usual scaling behavior is found to be preferable.
nucl-thPRC(2017)·20 citations
08
Deuteron-like states composed of two doubly charmed baryons
Lu Meng🇨🇳 · Ning Li🇩🇪 · Shi-Lin Zhu🇨🇳
We present a systematic investigation of the possible molecular states composed of a pair of doubly charmed baryons ( $Ξ_{cc} Ξ_{cc}$ ) or one doubly charmed baryon and one doubly charmed antibaryon $(Ξ_{cc} Ξ ˉ_{cc})$ within the framework of the one-boson-exchange-potential model. For the spin-triplet systems, we take into account the mixing between the $^{3} S_{1}$ and $^{3} D_{1}$ channels. For the baryon-baryon system $Ξ_{cc} Ξ_{cc}$ with $(R, I) = (3 ˉ, 1/2)$ and $(3 ˉ, 0)$ , where $R$ and $I$ represent the group representation and the isospin of the system, respectively, there exist loosely bound molecular states. For the baryon-antibaryon system $Ξ_{cc} Ξ ˉ_{cc}$ with $(R, I) = (8, 1)$ , $(8, 1/2)$ and $(8, 0)$ , there also exist deuteron-like molecules. The $B_{cc} B ˉ_{cc}$ molecular states may be produced at LHC. The proximity of their masses to the threshold of two doubly charmed baryons provides a clean clue to identify them.
↳ hep-phhep-exnucl-thPRD(2017)·43 citations
09
First-principle calculations of Dark Matter scattering off light nuclei
C. Körber🇩🇪 · A. Nogga🇩🇪 · J. de Vries🇳🇱
We study the scattering of Dark Matter particles off various light nuclei within the framework of chiral effective field theory. We focus on scalar interactions and include one- and two-nucleon scattering processes whose form and strength are dictated by chiral symmetry. The nuclear wave functions are calculated from chiral effective field theory interactions as well and we investigate the convergence pattern of the chiral expansion in the nuclear potential and the Dark Matter-nucleus currents. This allows us to provide a systematic uncertainty estimate of our calculations. We provide results for $^{2}$ H, $^{3}$ H, and $^{3}$ He nuclei which are theoretically interesting and the latter is a potential target for experiments. We show that two-nucleon currents can be systematically included but are generally smaller than predicted by power counting and suffer from significant theoretical uncertainties even in light nuclei. We demonstrate that accurate high-order wave functions are necessary in order to incorporate two-nucleon currents. We discuss scenarios in which one-nucleon contributions are suppressed such that higher-order currents become dominant.
↳ hep-phnucl-thPRC(2017)·59 citations

Affiliations

first authorsco-authorsvia INSPIRE