Nuclear Theory·nucl-th

Thursday·May 10, 2018

8 papers—5 primary·3 cross-listed

01
[Submitted on 9 May 2018]
Nuclear surface diffuseness revealed in nucleon-nucleus diffraction
S. Hatakeyama · W. Horiuchi · A. Kohama
Nuclear surface provides useful information on nuclear radius, nuclear structure as well as properties of nuclear matter. We discuss the relationship between the nuclear surface diffuseness and elastic scattering differential cross section at the first diffraction peak of high-energy nucleon-nucleus scattering as an efficient tool in order to extract the nuclear surface information from limited experimental data involving short-lived unstable nuclei. The high-energy reaction is described by a reliable microscopic reaction theory, the Glauber model. Extending the idea of the black sphere model, we find one-to-one correspondence between the nuclear bulk structure information and proton elastic scattering diffraction peak. This implies that we can extract both the nuclear radius and diffuseness simultaneously, using the position of the first diffraction peak and its magnitude of the elastic scattering differential cross section. We confirm the reliability of this approach by using realistic density distributions obtained by a mean-field model.
Comments:
12 pages, 12 figures, to appear in Phys. Rev. C
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1805.03325 [pdf]
PRC(2018)·32 citations
02
[Submitted on 9 May 2018]
Role of hexadecapole deformation of projectile $^{28}$ Si in heavy-ion fusion reactions near the Coulomb barrier
Gurpreet Kaur🇮🇳 · K. Hagino🇯🇵 · N. Rowley🇫🇷
The vast knowledge of strong influence of quadrupole deformation $β_{2}$ of colliding nuclei on heavy-ion subbarrier fusion reactions inspires a desire to quest the sensitivity of fusion dynamics to higher order deformations, such as $β_{4}$ and $β_{6}$ deformations. However, such studies have rarely been carried out, especially for deformation of projectile nuclei. In this article, we investigated the role of $β_{4}$ of the projectile nucleus in fusion of the $^{28}$ Si + $^{92}$ Zr system. We demonstrated that the fusion barrier distribution is sensitive to the sign and the value of the $β_{4}$ parameter of the projectile, $^{28}$ Si, and confirmed that the $^{28}$ Si nucleus has a large positive $β_{4}$ . This study opens an indirect way to estimate deformation parameters of radioactive nuclei using fusion reactions, which is otherwise difficult due to experimental constraints.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1805.03395 [pdf]
PRC(2018)·15 citations
03
[Submitted on 9 May 2018]
Nuclear structure in Parity Doublet Model
Myeong-Hwan Mun🇰🇷 · Ik Jae Shin🇰🇷 · Won-Gi Paeng🇰🇷 · Masayasu Harada🇯🇵 · Youngman Kim🇰🇷
Using an extended parity doublet model with the hidden local symmetry, we study some properties of nuclei in the mean field approximation to see if the parity doublet model could reproduce nuclear properties and also to estimate the value of the chiral invariant nucleon mass $m_{0}$ preferred by nuclear structure. We first determine our model parameters using the inputs from free space and from nuclear matter properties. Then, we study some basic nuclear properties such as the nuclear binding energy with several different choices of the chiral invariant mass. We observe that our results approach the experimental values as $m_{0}$ is increased until $m_{0} = 700$ MeV and start to deviate more from the experiments afterwards with $m_{0}$ larger than $m_{0} = 700$ MeV. From this observation, we conclude that $m_{0} = 700$ MeV is preferred by nuclear properties. We then calculate some properties of several selected nuclei with $m_{0} = 700$ MeV and compare them with experiments. Finally, we study the neutron-proton mass difference in some nuclei.
Comments:
6 pages, 3 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1805.03402 [pdf]
EPJA(2023)·16 citations
04
[Submitted on 9 May 2018]
Joint $R_{AA}$ and $v_{2}$ predictions for $P b + P b$ collisions at the LHC within DREENA-C framework
Dusan Zigic🇷🇸 · Igor Salom🇷🇸 · Jussi Auvinen🇷🇸 · Marko Djordjevic🇷🇸 · Magdalena Djordjevic🇷🇸
In this paper, we presented our recently developed DREENA-C framework, which is a fully optimized computational suppression procedure based on our state-of-the-art dynamical energy loss formalism in constant temperature finite size QCD medium. With this framework, we for the first time, generated joint $R_{AA}$ and $v_{2}$ predictions within our dynamical energy loss formalism. The predictions are generated for both light and heavy flavor probes, and different centrality regions in $P b + P b$ collisions at the LHC, and compared with the available experimental data. Despite the fact that DREENA-C does not contain medium evolution (to which $v_{2}$ is largely sensitive) and the fact that other approaches faced difficulties in explaining $v_{2}$ data, we find that DREENA-C leads to qualitatively good agreement with this data, though quantitatively, the predictions are visibly above the experimental data. Intuitive explanation behind such results is presented, supporting the validity of our model, and it is expected that introduction of evolution in the ongoing improvement of DREENA framework, will lead to better joint agreement with $R_{AA}$ and $v_{2}$ data, and allow better understanding of the underlying QCD medium.
Comments:
7 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1805.03494 [pdf]
J.Phys.G(2019)·38 citations
05
[Submitted on 9 May 2018]
Behavior of the collective rotor in wobbling motion
E. Streck · Q. B. Chen · N. Kaiser · Ulf-G. Meißner
The behavior of the collective rotor in wobbling motion is investigated within the particle-rotor model for the nucleus $^{135}$ Pr by transforming the wave functions from the $K$ -representation to the $R$ -representation. After reproducing the experimental energy spectra and wobbling frequencies, the evolution of the wobbling mode in $^{135}$ Pr, from transverse at low spins to longitudinal at high spins, is illustrated by the distributions of the total angular momentum in the intrinsic reference frame (azimuthal plot). Finally, the coupling schemes of the angular momenta of the rotor and the high- $j$ particle for transverse and longitudinal wobbling are obtained from the analysis of the probability distributions of the rotor angular momentum ( $R$ -plots) and their projections onto the three principal axes ( $K_{R}$ -plots).
Comments:
21 pages, 9 pages
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1805.03633 [pdf]
PRC(2018)·54 citations

Affiliations

first authorsco-authorsvia INSPIRE

Nuclear surface diffuseness revealed in nucleon-nucleus diffraction

Role of hexadecapole deformation of projectile 28Si in heavy-ion fusion reactions near the Coulomb barrier

Nuclear structure in Parity Doublet Model

Joint RAA​ and v2​ predictions for Pb+Pb collisions at the LHC within DREENA-C framework

Behavior of the collective rotor in wobbling motion

Affiliations

Role of hexadecapole deformation of projectile $^{28}$ Si in heavy-ion fusion reactions near the Coulomb barrier

Joint $R_{AA}$ and $v_{2}$ predictions for $P b + P b$ collisions at the LHC within DREENA-C framework