Nuclear Theory·nucl-th

Friday·April 24, 2026

9 papers—5 primary·4 cross-listed

01
Systematic VQE Benchmarking of the Deuteron, Triton, and Helium-3 within Lattice Pionless Effective Field Theory
Pınar Çifci🇹🇷 · Serkan Akkoyun🇹🇷 · Lloyd Ronde🇬🇧
We investigate the performance of quantum algorithms for light nuclear systems by studying the deuteron (2H), triton (3H), and helium-3 (3He) nuclei within a lattice formulation of pionless effective field theory (EFT). We first compute ground-state energies using classical exact diagonalization (ED), serving as a benchmark reference for variational quantum algorithms. We then perform Variational Quantum Eigensolver (VQE) calculations using noiseless classical statevector simulations of quantum circuits, enabling a controlled assessment of algorithmic performance in the absence of hardware-induced noise. We calibrate the two-body low-energy constant using the deuteron system and fit the three-body interaction strength to the triton, then consistently apply the resulting Hamiltonian parameters to the helium-3 nucleus. Our VQE calculations employ physically motivated ansatze targeting the relevant particle-number sector, with explicit particle-number-conserving constructions implemented for the triton and helium-3 systems. The variational optimization includes an analysis of the Hamiltonian energy variance roviding additional insight into convergence behavior and the quality of the variational states. We find that the VQE results are in good agreement with the corresponding classical ED ground-state energies across all three systems, including the isospin-asymmetric helium-3 nucleus with Coulomb interactions. Overall, our study provides a transparent and reproducible benchmark for assessing the applicability of variational quantum algorithms to few-body nuclear systems. Additionally, we perform a noisy VQE simulation with a depolarizing noise model for the triton system to illustrate the impact of realistic Noisy Intermediate-Scale Quantum (NISQ)-era hardware noise on variational energy estimation.
nucl-th0 citations
02
Conformal prediction for uncertainties in the neutron star equation of state
Habib Yousefi Dezdarani · Ryan Curry · Cassandra L. Armstrong · Alexandros Gezerlis
We study uncertainties in the equation of state of neutron stars using conformal prediction as a distribution-free and model-agnostic method that provides coverage guarantees. In particular, we apply the Conformalized Quantile Regression (CQR) method to posterior samples calculated from Bayesian inference, creating reliable uncertainty bands without assuming a specific form of the underlying distribution. We first construct CQR bands as a postprocessing step to the posterior samples of neutron star mas-radius relations provided by the NMMA collaboration and to Quantum Monte Carlo calculations of pure neutron matter. In all cases, empirical coverage studies confirm the robustness of the method.
nucl-th2 citations
03
Octupole correlation effects on two-neutron transfer intensity in rare-earth nuclei
Kosuke Nomura
Impacts of octupole correlations on the low-lying $0^{+}$ states and two-neutron transfer intensities in rare-earth nuclei are investigated in terms of the interacting boson model that is based on the nuclear density functional theory. The octupole degrees of freedom are not only essential building blocks to describe properties of negative-parity states in the model, but also influence low-spin positive-parity states including excited $0^{+}$ states. The calculation produces a large number of low-energy $0^{+}$ states that contain significant amounts of octupole components, indicating important roles played by the octupole degrees freedom in this mass region. Octupole correlations are shown to make sizable contributions to the $(p, t)$ and $(t, p)$ transfer intensities and, in particular, to reproduce the discontinuous changes of these quantities near those nuclei with $N \approx 88$ or 90, which are observed experimentally as a signature of the shape phase transition.
nucl-thnucl-exPRC(2026)·2 citations
04
Ground-state properties of superheavy $Z = 122$ isotopes within the deformed relativistic Hartree-Bogoliubov theory in continuum
Jin-Hong Zhuang · Zhen-Hua Zhang · Yuan-Yuan Wang · Cong Pan · Kai-Yuan Zhang · Huan-Yu Zhang · Yu Sun
The ground-state properties of superheavy $Z = 122$ isotopes are investigated using the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc). Bulk properties, including binding energies, Fermi energies, nucleon separation energies, quadrupole deformations, and root-mean-square radii, are calculated. The results are compared with those obtained from the relativistic continuum Hartree-Bogoliubov (RCHB) theory. By examining the dependence on the angular-momentum cutoff and the effects of triaxial and octupole deformations, a strategy for determining the ground states is suggested. Furthermore, based on an analysis of the Fermi and nucleon separation energies, the proton and neutron drip lines for $Z = 122$ isotopes are determined within both the DRHBc and RCHB frameworks. The possible magic numbers $N = 184$ , 258, and 350 are also suggested. Finally, the evolution of single-particle levels, deformation, charge and neutron radii as well as average pairing gaps with increasing neutron number, is discussed.
nucl-thCPC(2026)·0 citations
05
Multi-Nucleon Transfer Reactions and the Creation and the Evolution of the Compound Nucleus
Matthew Kafker · Aurel Bulgac
We present the first implementation of a novel extension of the Generator Coordinate Method (GCM), dubbed the enhanced GCM (eGCM), which is applied to the grazing Multi-Nucleon Transfer (MNT) reaction $^{48}$ Ca+ $^{208}$ Pb near the Coulomb barrier. eGCM incorporates major qualitative differences with either Time-Dependent Hartree-Fock (TDHF) or GCM frameworks used until now for nuclear reactions. We demonstrate that the eGCM framework describes for the first time in a fully quantum microscopic framework the emergence and the time-evolution of Niels Bohr's 1936 conjectured Compound Nucleus (CN). The thermalization time extracted in eGCM is at least two orders of magnitude larger than the Eigenstate Thermalization Hypothesis (ETH) would predict.
nucl-th4 citations
06
Bayesian Inference of Dense-Matter Equations of State from Small-Radius Compact Stars with Twin-Star Scenarios
Xieyuan Dong · Hong Shen · Jinniu Hu · Ying Zhang
We investigate dense-matter equations of state (EOSs) within a Bayesian framework, with particular emphasis on whether recent small-radius compact-star candidates can be accommodated in a twin-star scenario. For the hadronic sector, we adopt a meta-modeling EOS constrained by the NICER mass--radius measurements of PSR J0030 $+$ 0451, PSR J0437 $-$ 4715, PSR J0614 $-$ 3329, and the massive pulsar PSR J0740 $+$ 6620. The hadronic inference indicates that PSR J0614 $-$ 3329 favors a somewhat softer EOS than the other two $\sim1.4\,M_\odot$ pulsars, while the $\sim2\,M_\odot$ constraint prevents the EOS from becoming too soft. We then introduce a strong first-order phase transition through a constant-speed-of-sound quark-matter segment. Using HESS J1731 $-$ 347 and XTE J1814 $-$ 338 to constrain the phase-transition parameters, we find a preferred transition density of $n_\mathrm{t}\sim2.7\text{--}2.8\,n_0$, a sizable energy-density jump of $600\text{--}700$ MeV, and a relatively large post-transition sound speed of $c_s^2/c^2\sim0.85$. Such a phase transition generates a disconnected hybrid branch with radii of about $6\text{--}7$ km at masses around $1.2\text{--}1.4\,M_\odot$, and strongly suppresses the dimensionless tidal deformability relative to the purely hadronic branch. This pronounced change in tidal deformability is a characteristic signature of the twin-star mechanism and may provide an important observational tool for identifying phase transitions in neutron-star matter in future multimessenger measurements. These results show that small-radius compact stars can provide direct constraints on both the strength of a first-order phase transition and the stiffness of the post-transition phase in dense matter.
↳ astro-ph.HEnucl-th1 citation
07
Dilepton Production as a Probe of Pion Condensation in Hot and Dense QCD Matter
Aritra Bandyopadhyay🇵🇱 · Chowdhury Aminul Islam🇮🇳 · Krzysztof Redlich🇵🇱 · Chihiro Sasaki🇵🇱
We investigate dilepton production from an isospin-asymmetric hot and dense medium in order to explore the role of isospin imbalance in electromagnetic spectral properties. We focus in particular on modifications of the dilepton production rate associated with the onset of pion condensation, which can occur in the presence of a finite isospin chemical potential. We employ the Nambu--Jona-Lasinio model with isoscalar--vector interaction. We examine the phase structure in the $T - μ_{I}$ plane and estimate the vector current correlator--resummed dilepton rate for an effective quark chemical potential. We find that the interplay between isospin asymmetry, pion condensation, and vector interactions leads to nontrivial modifications of the dilepton yield. In particular, we observe two key features of the pion condensed phase: an enhancement at lower invariant mass and a prominent plateau-like structure which also help clearly identify the pion condensed phase from a chirally broken/restored phase. These results highlight the potential sensitivity of dilepton observables to pion-condensed phase of QCD matter, with possible implications for future low-energy heavy-ion collision experiments as well as isospin-rich environments such as neutron star matter.
↳ hep-phnucl-thPRD(2026)·0 citations
08
Quark and gluon production in the presence of the time-varying chiral magnetic current
Kirill Tuchin🇺🇸
The chiral magnetic effect consists in the induction of the electric current along the direction of the magnetic field. The corresponding transport coefficient $b_{0}$ , known as the chiral magnetic conductivity, is proportional to the chiral imbalance in the medium. In many systems, such as quark-gluon plasma, $b_{0}$ is time-dependent. This paper studies the effect of the time variation of $b_{0}$ on the particle spectra and energy loss produced through the chiral Cherenkov and associated processes in Abelian and non-Abelian systems. The rates of all processes are derived in the ultra-relativistic approximation. The results are applied to the relativistic heavy-ion collisions utilizing a specific model describing the relaxation of the initial $P$ -odd domain within the quark-gluon plasma. The corresponding energy loss is computed. The results suggest strong polarization of jets in quark-gluon plasma.
↳ hep-phnucl-thPRD(2026)·1 citation
09
Heavy Quark Transport is Non-Gaussian Beyond Leading Log
Jean F. Du Plessis🇺🇸 · Bruno Scheihing-Hitschfeld🇺🇸
We find that heavy quark transport beyond leading logarithm at weak coupling is intrinsically non-Gaussian: the longitudinal momentum transfer distribution has asymmetric exponential tails that are crucial for equilibration dynamics. We show this by computing the leading-order momentum transfer kernel for relativistic heavy quarks in weakly coupled non-Abelian plasmas, matching perturbative momentum transfer on the thermal scale to hard-thermal-loop-resummed soft physics. This is the same structure previously found in strongly coupled holographic plasmas, showing that it is not peculiar to weak or strong coupling, conformality, or supersymmetry. We therefore expect that this is a robust feature that physical quark-gluon plasma should also exhibit.
↳ hep-phhep-thnucl-th2 citations

Affiliations

first authorsco-authorsvia INSPIRE