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Nuclear Theory·nucl-th

Tuesday·March 17, 2020

11 papers—6 primary·5 cross-listed

All11Primary6Cross-lists5
  1. 01

    The Problem of Renormalization of Chiral Nuclear Forces

    U. van Kolck🇫🇷

    Ever since quantum field theory was first applied to the derivation of nuclear forces in the mid-20th century, the renormalization of pion exchange with realistic couplings has presented a challenge. The implementation of effective field theories (EFTs) in the 1990s promised a solution to this problem but unexpected obstacles were encountered. The response of the nuclear community has been to focus on "chiral potentials" with regulators chosen to produce a good description of data. Meanwhile, a successful EFT without explicit pion exchange --- Pionless EFT --- has been formulated where renormalization is achieved order by order in a systematic expansion of low-energy nuclear observables. I describe how lessons from Pionless EFT are being applied to the construction of a properly renormalized Chiral EFT.

    nucl-thFront.in Phys.(2020)·84 citations
  2. 02

    Collision system size scan of collective flows in relativistic heavy-ion collisions

    S. Zhang🇨🇳 · Y. G. Ma🇨🇳 · G. L. Ma🇨🇳 · J. H. Chen🇨🇳 · Q. Y. Shou🇨🇳 · W. B. He🇨🇳 · C. Zhong🇨🇳

    Initial geometrical distribution and fluctuation can affect the collective expansion in relativistic heavy-ion collisions. This effect may be more evident in small system (such as B + B) than in large one (Pb + Pb). This work presents the collision system dependence of collective flows and discusses about effects on collective flows from initial fluctuations in a framework of a multiphase transport model. The results shed light on system scan on experimental efforts to small system physics.

    nucl-thhep-phnucl-exPLB(2020)·19 citations
  3. 03

    Exploring nuclear exotica at the limits

    A.V. Afanasjev · S.E. Agbemava · A. Taninah

    The study of nuclear limits has been performed and new physical mechanisms and exotic shapes allowing the extension of nuclear landscape beyond the commonly accepted boundaries have been established. The transition from ellipsoidal to toroidal shapes plays a critical role in potential extension of nuclear landscape to hyperheavy nuclei. Rotational excitations leading to the birth of particle (proton or neutron) bound rotational bands provide a mechanism for an extension of nuclear landscape beyond spin zero proton and neutron drip lines.

    nucl-thActa Phys.Polon.Supp.(2020)·3 citations
  4. 04

    Studying the doublet bands at the borders of the island of chiral candidates: the I case

    Rui Guo🇨🇳 · Yong-Hao Liu🇨🇳 · Jian Li🇨🇳 · Wu-Ji Sun🇨🇳 · Li Li🇨🇳 · Ying-Jun Ma🇨🇳

    Based on the reported positive-parity doublet bands in I, the corresponding experimental characteristics including rotational alignment have been discussed and corresponding configuration assignment is reexamined. The self-consistent tilted axis cranking relativistic mean-field calculations indicates that this doublet bands is built on configuration . In addition, adopting the two quasiparticles coupled with a triaxial rotor model, the excitation energies, energy staggering parameter , , effective angles, and have been discussed and also compared with the available data. All of these results support the interpretation of chiral doublet bands for the positive-parity doublet bands in I, and hence identify this nucleus as the border of the island of chiral candidates.

    nucl-thCPC(2020)·3 citations
  5. 05

    Excited states of odd-mass nuclei with different deformation-dependent mass coefficients

    M. Chabab · A. El Batoul · I. El-ilali · A. Lahbas · M. Oulne

    Experimental data indicate that the mass tensor of collective Bohr Hamiltonian cannot be considered as a constant but should be considered as a function of the collective coordinates. In this work our purpose is to investigate the properties of low-lying collective states of the odd nuclei Yb and Dy by using a new generalized version of the collective quadrupole Bohr Hamiltonian with deformation-dependent mass coefficients. The proposed new version of the Bohr Hamiltonian is solved for Davidson potential in shape variable, while the potential is taken to be equal to the harmonic oscillator. The obtained results of the excitation energies and B(E2) reduced transition probabilities show an overall agreement with the experimental data. Moreover, we investigate the effect of the deformation dependent mass parameter on energy spectra and transition rates in both cases, namely: when the mass coefficients are different and when they are equal. Besides, we will show the positive effect of the present formalism on the moment of inertia.

    nucl-thEur.Phys.J.Plus(2020)·10 citations
  6. 06

    Determination of Photonuclear Reaction Cross-Sections on stable p-shell Nuclei by Using Deep Neural Networks

    Serkan Akkoyun · Hüseyin Kaya · Abdulkadir Şeker · Saliha Yeşilyurt

    The photonuclear reactions which is induced by high-energetic photon are one of the important type of reactions in the nuclear structure studies. In this reaction, a target material is bombarded by photons with the energies in the range of gamma-ray energy scale and the photons can statistically be absorbed by a nucleus in the target material. In order to get rid of the excess energies of the excited target nuclei, it can first emit protons, neutrons, alphas and light particles according to the separation energy thresholds. After this emitting process, generally an unstable nucleus can be formed. By the investigation of this products forming after photonuclear reactions, nuclear structure information can be obtained. In the present work, ({\gamma}, n) photonuclear reaction cross-sections on stable p-shell nuclei have been estimated by using neural network method. The main purpose of this study is to find neural network structures that give the best estimations on the cross-sections and to compare them with each other and available literature data. According to the results, the method is convenient for this task.

    nucl-thnucl-exphysics.data-an0 citations

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first authorsco-authorsvia INSPIRE