Nuclear Theory·nucl-th

Friday·October 11, 2019

9 papers—6 primary·3 cross-listed

01
[Submitted on 10 Oct 2019]
Daejeon16 NN Interaction
Y. Kim · I. J. Shin · A. M. Shirokov · M. Sosonkina · P. Maris · J. P. Vary
We have developed a realistic nucleon-nucleon (NN) interaction, dubbed Daejeon16. We start from a SRG (similarity renormalization group) evolved chiral N3LO interaction. We then apply PETs (phase-equivalent transformations) to the SRG-evolved interaction. It turned out that the obtained in such a way Daejeon16 NN interaction provides a good description of various observables in light nuclei without NNN forces. In this contribution, we present our new results for some selected nuclei using the ab initio no-core shell model (NCSM) with the Daejeon16 interaction. One of the interesting results is that the ab initio NCSM with Daejeon16 clearly demonstrates the phenomenon of parity inversion in Be-11, i.e., the ground state in Be-11 has the spin-parity (1/2, +) in experiments contrary to the expectation from the conventional shell model
Comments:
6 pages, Proceedings of the International Conference `Nuclear Theory in the Supercomputing Era 2018' (NTSE-2018), IBS, Daejeon, South Korea, October 29 - November 2, 2018
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1910.04367 [pdf]
6 citations
02
[Submitted on 10 Oct 2019]
Deformed $K^{-}$ nuclei in the Skyrme-Hartree-Fock approach
Yun Jin🇨🇳 · Chao Feng Chen🇨🇳 · Xian-Rong Zhou🇨🇳 · Yi-Yuan Cheng🇨🇳 · H.-J. Schulze🇮🇹
The properties of kaonic nuclei are studied using a two-dimensional Skyrme-Hartree-Fock model with a $K N$ Skyrme force. We focus in particular on the instability of the solutions for a too strong $K N$ interaction, which determines a maximum value of the kaon binding in this approach. We then analyze the change of the deformation properties of several core-deformed nuclei caused by the added kaon, and find a shrinking of the core and in some cases a complete loss of deformation.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1910.04411 [pdf]
PTEP(2019)·5 citations
03
[Submitted on 10 Oct 2019]
How to determine the shape of nuclear molecules with polarized gamma-rays
Lorenzo Fortunato
A method has been recently proposed to establish the geometry of the alpha-cluster arrangement in $^{12}$ C making use of polarized gamma-rays. The ratio of intensities of scattered radiation at 90 degrees along and perpendicular to the initial direction of the electric field vector, called depolarization ratio, is a key quantity that allows to underpin the nature of totally symmetric modes of vibrations. This allows to connect with the underlying point-group structure and therefore to the geometric shape of the nuclear molecule. This method is reviewed for $^{12}$ C and extended to other configurations, such as three unequal clusters and four identical clusters (e.g. $^{16}$ O).
Comments:
Proceedings of the 24th edition of European Few Body Conference, Surrey, UK, 2-4 September 2019
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1910.04498 [pdf]
SciPost Phys.Proc.(2020)·0 citations
04
[Submitted on 10 Oct 2019]
Systematic investigations of positive-parity doublet bands with three-quasiparticle configurations in $^{125, 127, 129, 131}$ Cs
Rui Guo🇨🇳 · Wu-Ji Sun🇨🇳 · Jian Li🇨🇳 · Dong Yang🇨🇳 · Yonghao Liu🇨🇳 · Chengkun Ru🇨🇳 · Jihuai Chi🇨🇳
The experimental features of positive-parity doublet bands in the odd-\emph{A} cesium isotopes $^{125, 127, 129, 131}$ Cs, including angular momentum alignment, energy staggering, $B (M 1) / B (E 2)$ etc. are studied systematically and compared to those of the candidate chiral bands in the adjacent odd-odd Cs isotopes. The configuration assignments and the dynamics of these bands are discussed. The self-consistent tilted axis cranking relativistic mean-field calculations are performed with configuration reassigned to these bands. The experimental level schemes of four nuclei are well reproduced, and the calculations also show four nuclei have obvious triaxial deformations and thus support the candidate chiral doublet bands in $^{125, 127, 129, 131}$ Cs.
Comments:
18 pages, 10 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1910.04523 [pdf]
PRC(2019)·5 citations
05
[Submitted on 10 Oct 2019]
Spectator induced electromagnetic effects in heavy-ion collisions and space-time-momentum conditions for pion emission
V.Ozvenchuk🇵🇱 · A.Rybicki🇵🇱 · A.Szczurek🇵🇱 · A.Marcinek🇵🇱 · M.Kiełbowicz🇵🇱
We present our calculation of electromagnetic effects, induced by the spectator charge on Feynman- $x_{F}$ distributions of charged pions in peripheral $P b + P b$ collisions at CERN SPS energies, including realistic initial space-time-momentum conditions for pion emission. The calculation is performed in the framework of our simplified implementation of the fire-streak model, adopted to the production of both $π^{-}$ and $π^{+}$ mesons. Isospin effects are included to take into account the asymmetry in production of $π^{+}$ and $π^{-}$ at high rapidity. A comparison to a simpler model from the literature is made. We obtain a good description of the NA49 data on the $x_{F}$ - and $p_{T}$ -dependence of the ratio of cross sections $π^{+} / π^{-}$ . The experimental data favors short times ( $0.5 < τ < 2$ ~fm/ $c$ ) for fast pion creation in the local fire-streak rest frame. The possibility of the expansion of the spectators is considered in our calculation, and its influence on the electromagnetic effect observed for the $π^{+} / π^{-}$ ratio is discussed. In addition we discuss the relation between anisotropic flow and the electromagnetic distortion of $π^{+} / π^{-}$ ratios, and study the influence of transverse expansion of fire streaks as well as their vorticity on this distortion. In this latter study we find that inclusion of rotation of fire streaks in our model gives a satisfactory description of the rapidity dependence of pion directed flow. We conclude that {our implementation of the} fire-streak model, which properly describes the centrality dependence of $π^{-}$ rapidity spectra at CERN SPS energies, also provides a quantitative description of the electromagnetic effect on the $π^{+} / π^{-}$ ratio as a function of $x_{F}$ .
Comments:
12 pages, 15 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1910.04544 [pdf]
PRC(2020)·9 citations
06
[Submitted on 10 Oct 2019]
Observing the deformation of nuclei with relativistic nuclear collisions
Giuliano Giacalone🇫🇷
I show that particle collider experiments on relativistic nuclear collisions can serve as direct probes of the deformation of the colliding nuclear species. I argue that collision events presenting very large multiplicities of particles and very small values of the average transverse momentum of the emitted hadrons probe collision geometries in which the nuclear ellipsoids fully overlap along their longer side. By looking at these events one selects interaction regions whose elliptic anisotropy is determined by the deformed nuclear shape, which becomes accessible experimentally through the measurement of the elliptic flow of outgoing hadrons.
Comments:
v1: 6 pages ; 5 figures. v2: 5 pages; 4 figures. Version accepted for publication. Removed discussion of isobaric collisions (Fig. 5) to comply with space limitations. See the follow-up paper arXiv:2004.14463 for a phenomenological application
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1910.04673 [pdf]
PRL(2020)·102 citations
07
[Submitted on 9 Oct 2019] (cross-list from hep-ph)
Helicity-dependent generalization of the JIMWLK evolution
Florian Cougoulic🇺🇸 · Yuri V. Kovchegov🇺🇸
We generalize the JIMWLK evolution equation to include the small- $x$ evolution of helicity distributions. To derive helicity JIMWLK, we use the method devised by A.H. Mueller for the usual unpolarized JIMWLK, and apply it to the helicity evolution equations derived earlier. We obtain a functional evolution equation for the generalized JIMWLK weight functional. The functional now is a sum of a helicity-independent term and a helicity-dependent term. The kernel of the new evolution equation consists of the standard eikonal leading-order JIMWLK kernel plus new terms containing derivatives with respect to the sub-eikonal quark and gluon fields. The new kernel we derive can be used to generate the standard JIMWLK evolution and to construct small- $x$ evolution equations for flavor-singlet operators made of any number of light-cone Wilson lines along with one Wilson line containing sub-eikonal helicity-dependent local operator insertions (a "polarized Wilson line").
Comments:
26 pages, 17 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1910.04268 [pdf]
PRD(2019)·80 citations
08
[Submitted on 10 Oct 2019] (cross-list from hep-ph)
New solutions of viscous relativistic hydrodynamics
Mate Csanad🇭🇺 · Marton I. Nagy🇭🇺 · Ze-Fang Jiang🇨🇳 · Tamas Csorgo🇭🇺
Relativistic hydrodynamics represents a powerful tool to investigate the time evolution of the strongly interacting quark gluon plasma created in ultrarelativistic heavy ion collisions. The equations are solved often numerically, and numerous analytic solutions also exist. However, the inclusion of viscous effects in exact, analytic solutions has received less attention. Here we utilize Hubble flow to investigate the role of bulk viscosity, and present different classes of exact, analytic solutions valid also in the presence of dissipative effects.
Comments:
6 pages, 1 figure. Presented at the XIV Workshop on Particle Correlations and Femtoscopy, June 3-7, 2019, Dubna, Russia
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1910.04660 [pdf]
Phys.Part.Nucl.(2020)·1 citation
09
[Submitted on 10 Oct 2019] (cross-list from hep-ph)
Diffractive photoproduction of $J / ψ$ and $Υ$ using holographic QCD: gravitational form factors and GPD of gluons in the proton
Kiminad A. Mamo🇺🇸 · Ismail Zahed🇺🇸
We present a holographic analysis of diffractive photoproducton of charmonium $J / ψ$ and upsilonium $Υ$ on a proton, considered as a bulk Dirac fermion, for all ranges of $s$ , i.e., from near threshold to very high energy. Using the bulk wave functions of the proton and vector mesons, within holographic QCD, and employing Witten diagrams in the bulk, we compute the diffractive photoproduction amplitude of $J / ψ$ and $Υ$ . The holographic amplitude shows elements of the strictures of vector meson dominance (VMD). It is dominated by the exchange of a massive graviton or $2^{++}$ glueball resonances near threshold, and its higher spin-j counterparts that reggeize at higher energies. Both the differential and total cross sections are controlled by the gravitational form factor $A (t)$ , and compare well to the recent results reported by the GlueX collaboration near threshold and the world data at large $s$ . The holographic gravitational form factors, including the D-term, which is due to the exchange of massive spin-0 glueballs, are in good agreement with lattice simulations. We use it to extract the holographic pressure and shear forces inside the proton. Finally, using a pertinent integral representation of the holographic gravitational form factor $A (t)$ near threshold, and its Pomeron counterpart way above threshold, we extract the generalized parton distribution (GPD) of gluons inside the proton at different resolutions.
Comments:
40 pages, two columns, 23 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
1910.04707 [pdf]
PRD(2020)·139 citations

Affiliations

first authorsco-authorsvia INSPIRE