Mon·Jul 13, 2020Monday·July 13, 2020

1. 01*

   Time-dependent covariant density functional theory in 3D lattice space: benchmark calculation for 16O + 16O reaction

   Z. X. Ren🇨🇳 · P. W. Zhao🇨🇳 · J. Meng🇨🇳

   Time-dependent covariant density functional theory with the successful density functional PCPK1 is developed in a three-dimensional coordinate space without any symmetry restrictions, and benchmark calculations for the 16O + 16O reaction are performed systematically. The relativistic kinematics, the conservation laws of the momentum, total energy, and particle number, as well as the time-reversal invariance are examined and confirmed to be satisfied numerically. Two primary applications including the dissipation dynamics and above-barrier fusion cross sections are illustrated. The obtained results are in good agreement with the ones given by the nonrelativistic time-dependent density functional theory and the data available. This demonstrates that the newly developed time-dependent covariant density functional theory could serve as an effective approach for the future studies of nuclear dynamical processes.

   ↳ nucl-thnucl-exPRC(2020)·28 citations
2. 02*

   $QQ\bar{s}\bar{s}$ tetraquarks in the chiral quark model

   Gang Yang🇨🇳 · Jialun Ping🇨🇳 · Jorge Segovia🇪🇸

   The low-lying $S$-wave $QQ\bar{s}\bar{s}$ ($Q=c,b$) tetraquark states with $I{J}^P=00^{+}$, $01^{+}$ and $02^{+}$ are systematically investigated in the framework of complex scaling range of chiral quark model. Every structure including meson-meson, diquark-antidiquark and K-type configurations, and all possible color channels in four-body sector are considered by means of a commonly extended variational approach, Gaussian expansion method. Several narrow and wide resonance states are obtained for $cc\bar{s}\bar{s}$ and $bb\bar{s}\bar{s}$ tetraquarks with $I{J}^P=00^{+}$ and $02^{+}$. Meanwhile, narrow resonances for $cb\bar{s}\bar{s}$ tetraquarks are also found in $I{J}^P=00^{+}$, $01^{+}$ and $02^{+}$ states. These results confirm the possibility of finding hadronic molecules with masses $\sim 0.6\text{GeV}$ above the noninteracting hadron-hadron thresholds.

   ↳ hep-phhep-exhep-latnucl-ex+1PRD(2020)·37 citations
3. 03*

   Localization of peripheral reactions and sensitivity to the imaginary potential

   Imane Moumene🇮🇹 · Angela Bonaccorso🇮🇹

   The aim of the present study is to make for the first time in the literature a systematic and quantitative assessment of the evaluation of the imaginary part of the optical potential calculated within the folding model and its consequences on the localization of surface reactions. Comparing theoretical and experimental reaction cross sections, for some light projectiles on a ${}^9$Be target, it has recently been shown that a single-folded s.f. (light-) nucleus-${}^9$Be imaginary optical potential is more accurate than a double-folded d.f. optical potential. Within the eikonal formalism for the cross sections and phase shifts, the single-folded potential was obtained using a n-${}^9$Be phenomenological optical potential and microscopic projectile densities. This paper is a follow-up in which we systematically study a series of different light and medium-mass projectile induced reactions on ${}^9$Be. Our results confirm that the s.f. cross sections are larger than the d.f. cross sections and the effect increases with the projectile mass. Furthermore the strong absorption radius parameter extracted from the $S$ matrices calculated with the s.f. has a stable value $r_s$ =1.3 - 1.4 fm for all projectile masses in the range of incident energies 40-100AMeV. This indicates that a clear geometrical separation can be made between the region of surface reactions, the region of strong absorption into other channels and the region of weak nuclear interaction. The d.f. results are instead much scattered and the separation between surface reactions and other channels does not seem to be consistent. Excellent agreement with recent experimental results confirms the validity of our approach.

   ↳ nucl-thnucl-exNPA(2021)·5 citations
4. 04*

   A Study of Multifractal Analysis in 16O-AgBr Collisions at 60A and 200A GeV

   Nazeer Ahmad🇮🇳 · Tufail Ahmad🇮🇳 · Omveer Singh🇮🇳 · Shakeel Ahmad🇮🇳

   A multifractal analysis to study the multiparticle dynamics in 60A and 200A GeV/c 16O-AgBr collisions has been performed in the pseudorapidity phase space. Multifractal moments Gq as the function of pseudorapidity bin size for different order of the moments, q have been calculated. The power-law behaviour has been observed in the considered data sets. The variation of multifractal dimensions, Dq and multifractal spectral function, f($\alpha$q) with order of the moments, q have been studied thoroughly. Dq is found to decrease with increasing order of the moments, q indicating thereby a self-similar behaviour in the multiparticle production in the considered collisions. We have also found a concave downward curve of multifractal spectral function with maxima q=0.

   ↳ hep-exnucl-exnucl-thJ.Mod.Phys.(2018)·0 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.