Nuclear Theory·nucl-th

Wednesday·November 29, 2023

10 papers—5 primary·5 cross-listed

01
Variation of multi-Slater determinants in antisymmetrized molecular dynamics and its application to $^{10}$ Be with various clustering
Takayuki Myo · Mengjiao Lyu · Qing Zhao · Masahiro Isaka · Niu Wan · Hiroki Takemoto · Hisashi Horiuchi
We propose a method to optimize the multi-Slater determinants of the antisymmetrized molecular dynamics (AMD) in the linear combination form and apply it to the neutron-rich $^{10}$ Be nucleus. The individual Slater determinants and their weights in the superposition are determined simultaneously according to the variational principle of the energy of the total wave function. The multi-AMD basis states of $^{10}$ Be show various cluster structures as well as the shell-model type. In the cluster configurations, different intercluster distances are superposed automatically indicating the role of the generator coordinates. We further introduce a procedure to obtain the configurations for the excited states imposing the orthogonal condition to the ground-state configurations. In the excited states of $^{10}$ Be, the linear-chain-like structure is confirmed consisting of various clusters. The energy spectrum using the obtained basis states reproduces the experiments. The present framework can be the method to find the optimal multi-configuration for nuclear ground and excited states.
nucl-thnucl-exPRC(2023)·16 citations
02
Exotic nonaxial-octupole shapes in $N = 184$ isotones from covariant density functional theories
Jie Zhao · Zheng-Gang Wu
The nonaxial octupole shape in some nuclei with $N = 184$ , namely, $^{284}$ Fm, $^{286}$ No, $^{288}$ Rf, and $^{290}$ Sg, is investigated using covariant density functional theories. Employing the density-dependent point-coupling covariant density functional theory with the parameter set DD-PC1 in the particle-hole channel, it is found that the ground states of $^{284}$ Fm, $^{286}$ No, $^{288}$ Rf, and $^{290}$ Sg have pure nonaxial octupole shapes with deformation parameters $β_{31} \approx 0.08$ and $β_{33} \approx - 0.01 \sim - 0.03$ . The energy gain due to the $β_{31}$ and $β_{33}$ distortion is $\sim$ 1 MeV. The occurrence of the nonaxial octupole correlations is mainly from the proton orbitals $1 i_{13/2}$ and $2 f_{7/2}$ , which are close to the proton Fermi surface. The dependence of the nonaxial octupole effects on the form of the energy density functional and on the parameter set is also studied.
nucl-thnucl-exPRC(2024)·7 citations
03
Fusion and reactions of $α$ + $^{8}$ Be in the Hoyle resonance and associated resonances region
Teck-Ghee Lee · Orhan Bayrak · Cheuk-Yin Wong
The fusion of $α$ and $^{8}$ Be to produce a $^{12}$ C nucleus is a crucial process in nucleosynthesis. In the laboratory, this process can only be studied theoretically as a $^{8}$ Be target or projectile cannot be prepared experimentally. We use the potential scattering theory in the coupled-channel formalism to study such a process in terms of the collision between the $α$ particle on a deformed $^{8}$ Be nucleus, both on resonance and off resonance in the Hoyle resonance and associated resonances region. The experimental $^{12}$ C energy levels and widths constrain the nuclear potential to suggest the need to include a parity-dependent surface potential component that is more attractive for even- $L$ positive-parity partial waves than for odd- $L$ negative-parity partial waves. As a consequence, the radial dependence of the total potentials for the set of \{0 $^{+}$ , 2 $^{+}$ , 4 $^{+}$ \} resonances of $^{12}$ C exhibit a double-hump behavior, possessing two local energy minima and a doublet of each of the $^{12}$ C \{0 $^{+}$ , 2 $^{+}$ , 4 $^{+}$ \} resonances in the Hoyle and associated resonances region. We examine the approximate agreement of the theoretical results with experiment and suggest the search for the as-yet unobserved lower-energy 2 $_{2}^{+}$ and 4 $_{1}^{+}$ resonances to test the double-hump potential description. In addition, for practical astrophysical applications, we evaluate and estimate the astrophysical $S (E_{c.m.})$ -factor for the $α$ + $^{8}$ Be $\to$ $^{12}$ C $(0^{+*})$ $\to$ $^{12}$ C $(2_{1}^{+})$ + $γ$ reaction for $E_{c.m.}$ $<$ 1.0 MeV.
nucl-thastro-ph.SRquant-phPRC(2026)·0 citations
04
Universality in Ground State Masses of Nuclei
A. Bhagwat · Sudhir Ranjan Jain
The beautiful and profound result that the first eigenvalue of Schroedinger operator can be interpreted as a large deviation of certain kind of Brownian motion leads to possible existence of universality in the distribution of ground state energies of quantal systems. Existence of such universality is explored in the distribution of the ground state energies of nuclei with Z $\geq$ 8 and N $\geq$ 8. Specifically, it has been demonstrated that the nuclear masses follow extreme-value statistics, implying that the nuclear ground state energies indeed can be treated as extreme values in the sense of the large deviation theory of Donsker and Varadhan.
nucl-thcond-mat.stat-mechquant-ph0 citations
05
Adding Corrections to Global Spherical Potentials for Use in a Coupled-Channel Formulation
S. P. Weppner · Prakrut Patel · C. Miller · C. Ogg · I. Mazumdar
The coupled-channel technique augments a non-relativistic distorted wave born approximation scattering calculation to include a coupling to virtual states from the negative energy region. It has been found to be important in low energy nucleon-nucleus scattering. We modify the nucleon-nucleus standard optical potentials, not designed for a coupled-channel space, so they can be used in that setting. The changes are small and systematic. We use a standard scattering code to adjust a variety of optical potentials and targets such that the original fit to scattering observables are maintained as we incorporate the coupled-channel environment. Overall over forty target nuclei were tested from $A = 12$ to $A = 205$ and nucleon projectile energies from 1 MeV to 200 MeV. There is excellent improvement in fitting the scattering observables, especially for low energy neutron scattering.The corrections were found to be unimportant for projectile energies greater than 200 MeV. The largest changes are to the surface amplitudes while the real radii and the real central amplitude are modified by only a few percent, every other parameter is unchanged. This technique is general enough to be applied to a variety of inelastic theoretical calculations.
nucl-th0 citations
06
Quantum-classical simulation of quantum field theory by quantum circuit learning
Kazuki Ikeda🇺🇸
We employ quantum circuit learning to simulate quantum field theories (QFTs). Typically, when simulating QFTs with quantum computers, we encounter significant challenges due to the technical limitations of quantum devices when implementing the Hamiltonian using Pauli spin matrices. To address this challenge, we leverage quantum circuit learning, employing a compact configuration of qubits and low-depth quantum circuits to predict real-time dynamics in quantum field theories. The key advantage of this approach is that a single-qubit measurement can accurately forecast various physical parameters, including fully-connected operators. To demonstrate the effectiveness of our method, we use it to predict quench dynamics, chiral dynamics and jet production in a 1+1-dimensional model of quantum electrodynamics. We find that our predictions closely align with the results of rigorous classical calculations, exhibiting a high degree of accuracy. This hybrid quantum-classical approach illustrates the feasibility of efficiently simulating large-scale QFTs on cutting-edge quantum devices.
↳ hep-thcs.LGhep-phnucl-th+1Annalen Phys.(2025)·1 citation
07
A unified description of DGLAP, CSS, and BFKL: TMD factorization bridging large and small x
Swagato Mukherjee🇺🇸 · Vladimir V. Skokov🇺🇸 · Andrey Tarasov🇺🇸 · Shaswat Tiwari🇺🇸
This paper introduces a transverse-momentum dependent (TMD) factorization scheme designed to unify both large and small Bjorken-x regimes. We compute the next-to-leading order (NLO) quantum chromodynamics (QCD) corrections to the gluon TMD operator for an unpolarized hadron within this proposed scheme. This leads to the emergence of a new TMD evolution, incorporating those in transverse momentum, rapidity, and Bjorken-x. When matched to the collinear factorization scheme, our factorization scheme faithfully reproduces the well-established Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) and Collins-Soper-Sterman (CSS) evolutions. Conversely, matching with high-energy factorization not only yields the Balitsky-Fadin-Kuraev-Lipatov (BFKL) evolution but also reveals distinctive signatures of CSS logarithms. The development of this novel TMD factorization scheme, capable of seamlessly reconciling disparate Bjorken-x regimes and faithfully reproducing established QCD evolution equations, has the potential to significantly advance our comprehension of high-energy processes and three-dimensional parton structures of hadrons.
↳ hep-phhep-exhep-lathep-th+1PRD(2024)·36 citations
08
Is gauge symmetry vacuous or physical ? : Lessons from the Landau problem as a solvable quantum gauge theoretical system
Masashi Wakamatsu🇯🇵
The gauge symmetry is one of the most important concepts in modern physics, but there are two conflicting views on its meaning or interpretation. The standard view is that local gauge symmetry is the basis of the pursue of fundamental particles and forces in nature. Another view is that the gauge symmetry is not a symmetry of nature but just a redundancy in description. Naturally, both statements are nothing wrong, but one might feel that there is a slight conceptual conflict between the two points of view. Due to the subtlety of the subject, however, little literature exists that discusses the root of such an anxiety. In the present paper, by making full use of the analytically solvable nature of the quantum Landau problem, we argue that the familiar gauge principle plays a critical role in unraveling a subtle mismatch between the two viewpoints above. We reveal that there exist two types of quantities in gauge theories, which should clearly be discriminated. The first are quantities, which look seemingly gauge-invariant but actually not, whereas the second are genuinely gauge-invariant quantities, which correspond to direct experimental observables.
↳ quant-phhep-phnucl-th0 citations
09
Cost of inferred nuclear parameters towards the f-mode dynamical tide in binary neutron stars
Bikram Keshari Pradhan · Tathagata Ghosh · Dhruv Pathak · Debarati Chatterjee
Gravitational Wave (GW) observations from Neutron Stars (NS) in a binary system provide an excellent scenario to constrain the nuclear parameters. The investigation of Pratten et al. (2022) has shown that the ignorance of f-mode dynamical tidal correction in the GW waveform model of the binary neutron star (BNS) system can lead to substantial bias in the measurement of NS properties and NS equations of state (EOS). In this work, we investigate the bias in the nuclear parameters resulting from the ignorance of dynamical tidal correction. In addition, this work demonstrates the sensitivity of the nuclear parameters and the estimated constraints on them from future GW observations. We infer the nuclear parameters from GW observations by describing the NS matter within the relativistic mean field model. For a population of GW events, we notice that the ignorance of dynamical tide predicts a lower median for nucleon effective mass ( $m^{*}$ ) by $\sim 6%$ compared to the scenario when dynamical tidal correction is considered. Whereas at a 90\% credible interval(CI), $m^{*}$ gets constrained up to $\sim 5%$ and $\sim 3%$ in A+ (the LIGO-Virgo detectors with a sensitivity of 5th observing run) and Cosmic Explorer (CE) respectively. We also discuss the resulting constraints on all other nuclear parameters, including compressibility, symmetry energy, and slope of symmetry energy, considering an ensemble of GW events. We do not notice any significant impact in analyzing nuclear parameters other than $m^{*}$ due to the ignorance of f-mode dynamical tides.
↳ gr-qcastro-ph.HEnucl-thApJ(2024)·16 citations
10
New insights into the doubly charmed exotic mesons
Di Guo🇨🇳 · Qin-He Yang🇨🇳 · Ling-Yun Dai🇨🇳 · A. P. Szczepaniak🇺🇸
Using effective Lagrangians constrained by the heavy quark spin symmetry and chiral symmetry, for the light quarks, we analyze the $D^{0} D^{0} π^{+}$ , $D ˉ^{0} D^{0} π^{0}$ and $D^{0} D ˉ^{* 0}$ invariant mass spectra. Performing a simultaneous analysis of the doubly charmed and charm-anti-charm states gives further insights into the nature of the $T_{cc}^{+}$ and $χ_{c 1}^{0} (3872)$ , exotic hadrons. It is confirmed that both states should lie below their respective $D D^{*}$ / $D D ˉ^{*}$ thresholds. Also, the contributions of the triangle and box diagrams are negligible.
↳ hep-phnucl-thEPJC(2025)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE