Nuclear Theory·nucl-th

Wednesday·June 10, 2026

18 papers—10 primary·8 cross-listed

01
[Submitted on 8 Jun 2026]
Thermodynamic versus Dynamical Description of the Neutron-Star Crust-Core Instability: Implications for Crustal Observables
Athul Kunjipurayil🇺🇸 · J. Piekarewicz🇺🇸
We investigate the crust-core transition in neutron stars using both thermodynamic and dynamical descriptions of the instability. In the thermodynamic approach, the transition is identified through the vanishing of a generalized incompressibility coefficient signaling the onset of a bulk spinodal instability. In contrast, the dynamical approach based on the relativistic random-phase approximation (RPA) incorporates Coulomb screening and finite-size effects that determine the instability at finite wavelength. Using a family of covariant energy density functionals spanning a broad range of symmetry-energy slopes, we show that the dynamical treatment systematically predicts lower transition densities and pressures compared to the thermodynamic approach. We further demonstrate that the RPA instability develops at a characteristic length scale set by the competition among bulk, Coulomb, and surface effects. Most importantly, we show that these differences propagate directly into neutron-star observables. Because the thermodynamic approach predicts larger transition pressures, it generates thicker crusts and significantly larger crustal fractions of the stellar moment of inertia than the dynamical-RPA framework -- with important implications for the interpretation of pulsar glitches and other crust-sensitive neutron-star observables.
Comments:
11 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Experiment (nucl-ex)
arXiv:
2606.10090 [pdf]
1 citation
02
[Submitted on 8 Jun 2026]
Determining universal spectra from probability distributions
Charles Kacir · Joseph Moscoso · Amy Nicholson · Thomas R. Richardson · Cade Rodgers
The probability distribution of a two-particle correlation function computed over background auxiliary field configurations, used to generate the interactions, has been shown to inform about the spectra of universal $n$ -body clusters [1]. Here, we utilize two approaches, a numerical lattice computation and an analytic expansion in the limit of large numbers of identical species, in an attempt to refine the initial predictions. Exploratory calculations in these directions are presented, and future investigations laid out.
Comments:
Proceedings from the ECT* Workshop "Universality in strongly- interacting systems: from QCD to atoms", June 2025
Subjects:
Nuclear Theory (nucl-th); Quantum Gases (cond-mat.quant-gas); High Energy Physics — Lattice (hep-lat)
arXiv:
2606.10128 [pdf]
0 citations
03
[Submitted on 8 Jun 2026]
Charm quark production in heavy-ion collisions as a signature of pre-equilibrium
Maurice Coquet🇨🇭 · Thomas Faure🇫🇷 · Sören Schlichting🇩🇪 · Mika Spier🇫🇷 · Michael Winn🇫🇷
The relative abundances and kinematic distributions of hadrons containing (anti)charm quarks are key observables for deconfinement, heavy-quark diffusion and hadronization in heavy-ion collisions. The production of (anti)charm quarks is commonly associated to the initial hard scatterings in hadronic collisions. Based on previous studies on dilepton production, we evaluate the (anti)charm quark production from the pre-equilibrium phase. A non-negligible contribution to the overall charm quark production is found albeit large theoretical uncertainties are limiting factors. We conclude that precise total charm production measurements combined with progress on charm production calculations from the initial hard scatterings can be used to infer information on the pre-equilibrium stage.
Comments:
8 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2606.10206 [pdf]
0 citations
04
[Submitted on 8 Jun 2026]
Nonflow Subtraction Beyond Two-Particle Correlations
Zaining Wang🇨🇳 · Jiangyong Jia🇺🇸 · Jinhui Chen🇨🇳 · Shengli Huang🇺🇸 · Chunjian Zhang🇨🇳 · Zhengxi Yan🇺🇸
Establishing collective flow in small collision systems is crucial for pinning down the minimum conditions for quark-gluon plasma (QGP) formation. In two-particle correlations, nonflow has been subtracted with good control, pushing the reach of flow measurements down to very small particle multiplicities $N$ . However, the multi-particle nature of collectivity has not been established in the same $N$ regime, because the residual nonflow surviving the subevent procedure in multi-particle cumulants has never been quantified. We develop a general nonflow subtraction framework for $m$ -particle cumulants, built around the approximate $1/ N^{m - 1}$ scaling of nonflow in the independent-source picture. Correlators containing $v_{1}$ serve as clean nonflow estimators, since the $p_{T}$ -integrated dipolar flow nearly vanishes. Using \HIJING{} as a controlled nonflow-only environment, we test the subtraction for three target observables ( $⟨ v_{2}^{2} ⟩$ , $⟨ v_{2}^{2} δ p_{T} ⟩$ , and $c_{2} {4}$ ) in O+O and $d$ +Au at $s_{NN} = 5.36$ TeV and 200 GeV. Most of the nonflow is removed, with residual fractions typically within 20--30% when converted to the two-particle level, though the best estimator differs across the three targets. We identify a multiplicity-reweighting correction, previously overlooked in two-particle correlations, that explains the long-standing undersubtraction of the naive $1/ N$ -scaling method; its impact grows as a power of the correlator order. The framework gives a systematic route to nonflow subtraction beyond two-particle correlations, broadening the class of multi-particle observables accessible to the small-system flow program.
Comments:
18 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2606.10258 [pdf]
2 citations
05
[Submitted on 9 Jun 2026]
Global polarization of $Λ$ , $Ξ^{-}$ , and $Ω^{-}$ hyperons in Au+Au collisions at RHIC BES-II energies
Gen-Hui Li🇨🇳 · Cong Yi🇨🇳 · Xiang-Yu Wu🇨🇦 · Shi Pu🇨🇳 · Guang-You Qin🇨🇳
We investigate the global spin polarization of $Λ$ hyperons and the multi-strange hyperons $Ξ^{-}$ and $Ω^{-}$ in Au+Au collisions across the RHIC Beam Energy Scan II (BES-II) energy range, $s_{N N} = 7.7$ -- $27$ GeV. The polarization is computed using the modified Cooper--Frye formula, which includes contributions from thermal vorticity, the thermal shear tensor, and the gradient of the baryon chemical potential, combined with the (3+1)-dimensional viscous hydrodynamic framework CLVisc with SMASH initial conditions. We present the global polarization as a function of collision energy, centrality, transverse momentum, and rapidity. We find that the global polarization of $Ω^{-}$ is systematically larger than those of $Λ$ and $Ξ^{-}$ because of its larger spin quantum number, but it remains below the central value of the recent STAR measurement. This discrepancy may suggest that additional mechanisms, such as spin correlations among strange quarks inside the $Ω^{-}$ , could contribute to the observed $Ω^{-}$ polarization. We also find that the global-polarization splitting between hyperons and anti-hyperons increases toward lower collision energies and is dominated by the chemical-potential-gradient contribution.
Comments:
8 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2606.10341 [pdf]
0 citations
06
[Submitted on 9 Jun 2026]
Neural-network solution of subtracted three-body Faddeev integral equations near the Efimov limit
Lucas A. Souza🇧🇷
We apply a deep-neural-network (DNN) ansatz to the symmetrized spectator vector of the subtracted three-body Faddeev integral equation for identical bosons near the Efimov limit. The network is trained by minimizing the residual of the discretized integral equation, while the positive binding scale associated with the three-body energy is treated as a trainable parameter. Deterministic diagonalization of the same discretized kernel is used only as an a posteriori numerical benchmark. As preliminary validation, the neural-solver strategy is tested on the analytically solvable hydrogen radial problem. At unitarity, the DNN reproduces the Efimov ground-state binding scale with a DNN--deterministic deviation of $0.022%$ , while the first excited state is recovered to $0.002%$ . The deterministic solver recovers the universal Efimov scaling ratio $e^{2 π / s_{0}} ≃ 515.03$ , and the neural method traces the bound-state branches as a function of the inverse scattering length $1/ a$ by continuation from the unitary solution. These results indicate that DNN-based residual minimization can provide a compact and differentiable representation of a renormalized few-body integral-equation solution in a regime governed by discrete scale invariance.
Subjects:
Nuclear Theory (nucl-th); Mathematical Physics (math-ph); math.MP (math.MP); Quantum Physics (quant-ph)
arXiv:
2606.10343 [pdf]
Few Body Syst.(2026)·0 citations
07
[Submitted on 9 Jun 2026]
Sequential Clusterization of Light Nuclei and Hypernuclei in Heavy-Ion Collisions within a Wigner Function Coalescence Framework
Junyi Han🇨🇳 · Yue-Hang Leung🇩🇪 · Jiaxing Zhao🇩🇪 · Yingjie Zhou🇩🇪 · Norbert Herrmann🇩🇪 · Yaping Wang🇨🇳
We investigate the formation of light nuclei and hypernuclei in Au+Au collisions at $s_{N N} = 3 GeV$ within a coalescence framework embedded in the microscopic N-body Parton-Hadron-Quantum-Molecular Dynamics (PHQMD) transport model. The Wigner phase-space distributions employed in the coalescence calculation are constructed from realistic $N$ -body wave functions obtained by solving the Schrödinger equation in the hyperspherical harmonics formalism, providing a solid and parameter-free description of nuclear clusters and hypernuclei. By comparing calculated rapidity distributions with STAR data, we extract species-dependent coalescence times, revealing a non-universal formation pattern among different clusters. The resulting yields and kinematic distributions of light nuclei and hypernuclei are systematically analyzed and shown to be sensitive to the underlying wave-function structure and formation time. In addition, we explore cluster-nucleon formation channels for $A = 4$ systems. These additional channels improve the description of $^{4} He$ and $_{Λ}^{4} H$ yields and help address the underestimation of $A = 4$ cluster production in theoretical approaches. Finally, we provide predictions for heavier hypernuclei, including $_{Λ}^{5} He$ and $_{ΛΛ}^{5} He$ , which are of interest for future experimental measurements.
Comments:
13 pages, 13 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2606.10441 [pdf]
0 citations
08
[Submitted on 9 Jun 2026]
Simultaneous $α β$ Decay: A New Mode of Nuclear Instability
Wenqiang Zhang🇨🇳 · Chong Qi🇸🇪
We propose simultaneous $α β$ decay as a novel mode of nuclear instability that involves the strong and weak interactions in a single quantum transition. We develop a theoretical framework to predict its branching ratios and $α$ -energy spectra, establishing exclusive and inclusive criteria based on whether the individual $α$ and $β$ channels are closed or open. A global survey of the nuclear chart identifies five exclusive $α β^{-}$ candidates, all predicted to be experimentally inaccessible, and ranks the leading inclusive candidates for both the $α β^{-}$ and $α β^{+}$ modes. Remarkably, six of the top $α β^{+}$ candidates coincide with known $β$ -delayed- $α$ precursors. The observed $α$ spectra are naturally accounted for by simultaneous $α β^{+}$ emission, suggesting direct decay as the dominant underlying mechanism. Our findings establish simultaneous $α β$ decay as a distinct radioactive process and a sensitive probe of the interplay between the strong and weak interactions.
Comments:
6 pages, 2 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2606.10567 [pdf]
0 citations
09
[Submitted on 9 Jun 2026]
Gaussian vs. Real Wavefunction of Nuclear Clusters and Hypernuclei
Jiaxing Zhao🇩🇪 · Joerg Aichelin🇫🇷 · Elena Bratkovskaya🇩🇪
We compare realistic $N$ -body wave functions obtained from solutions of the Schrödinger equation with Gaussian ansätze constrained to the same rms radius. The microscopic wave functions exhibit significantly broader spatial distributions, revealing pronounced non-Gaussian structures. In addition, we investigate possible production channels for $A = 4$ clusters using a phenomenological two-body interaction. This study provides a potential mechanism that may help alleviate the underestimation of $A = 4$ cluster yields in theoretical models compared to experimental data.
Comments:
Contribution to: SQM2026
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2606.11008 [pdf]
1 citation
10
[Submitted on 9 Jun 2026]
Quantum Monte Carlo calculations of Zemach moments in $A \leq 9$ nuclei
Garrett B. King🇺🇸 · Sonia Bacca🇩🇪 · Graham Chambers-Wall🇺🇸 · Alex Gnech🇺🇸 · Saori Pastore🇺🇸 · Maria Piarulli🇺🇸 · Robert B. Wiringa🇺🇸
Modern atomic spectroscopy has reached a level of precision at which nuclear-structure effects can no longer be neglected and must be quantified reliably. In particular, hyperfine splittings depend on the Zemach radius, which encodes the convolution of the nuclear charge and magnetization distributions. The third electric Zemach moment provides a related finite-size measure and enters the elastic two-photon-exchange contribution to the Lamb shift in muonic atoms. Here, we compute Zemach radii and other electromagnetic moments for light nuclei using quantum Monte Carlo techniques within modern \textit{ab initio} nuclear theory. Using Norfolk two- and three-body interactions derived within chiral effective field theory, we assess the model dependence and study the role of two-body currents. For $^{6}$ Li, we obtain a Zemach radius larger than that extracted from atomic measurements, consistent with recent calculations, confirming that the discrepancy is not an artifact of the nuclear model. For $^{9}$ Be, our results agree with experiment; the discrepancy of previous phenomenological evaluations is traced to a model-dependent input for the magnetic radius.
Comments:
2 figures, 9 pages
Subjects:
Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
arXiv:
2606.11153 [pdf]
1 citation
11
[Submitted on 24 May 2026] (cross-list from astro-ph.HE)
Pulse Modulation as a Signature of the Asteroid-Neutron Star Collision Model for High-Energy Transients
Partha Bagchi🇮🇳 · Biswanath Layek🇮🇳 · Dheeraj Saini🇮🇳 · Anjishnu Sarkar🇮🇳 · Ajit M. Srivastava🇮🇳 · Deepthi Godaba Venkata🇮🇳
Asteroid-neutron star collision models have been proposed as possible sources of high-energy transients, such as gamma-ray bursts (GRBs) and fast radio bursts (FRBs). The sequence of events following the impact of the asteroid and finally dissolving into the neutron star can have several other observable consequences. We propose that due to the development of the off-diagonal moment of inertia (MI) components, the merger's aftermath can lead to the wobbling of the pulsar (assuming the neutron star happens to be a pulsar). Using sample values of various parameters, viz., size, shape, the locations of the deposits, and the pre-existing pulsar deformation parameter ( $η$ ), we calculate the detailed pulse profile modulation of the pulsar. We observe a distinct pattern of pulse profile modulation on a characteristic timescale enhanced by a factor of $1/ η$ compared to the pulse timing. Importantly, even small changes in the MI components, of order $ϵ$ , can produce large pulse profile modulations of order $ϵ / η$ (depending on the relative location of asteroid material deposition). Thus, if an asteroid-neutron star collision is responsible for a high-energy transient, the associated pulse profile modulation may serve as a falsifiable observational signature of such an event.
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); physics.class-ph (physics.class-ph); Computational Physics (physics.comp-ph)
arXiv:
2605.24886 [pdf]
MNRAS(2026)·1 citation
12
[Submitted on 8 Jun 2026] (cross-list from cs.LG)
Integrating Out, Twice:The Open-System Case That Neural-Network Ensemble Theory Is Missing
Jin Lei
Averaging a neural network over its random parameters and marginalizing a Gaussian sector are the same operation, the Schur complement of the eliminated block, and when that block is closed it returns a covariance and its inverse. That is all a network ensemble produces, the closed case. The open case is missing, and nuclear reaction theory has it worked out. Projecting a scattering problem onto a chosen set of channels, with the rest carrying probability irreversibly to a continuum, leaves a non-Hermitian effective generator that conserves and itemizes exactly what it loses: the nuclear optical model and its generalized optical theorem. I set the two cases side by side using only the moments of a distribution, the algebra of Gaussians, and block inversion, no field theory, and give the closed-case dictionary in full: the neural tangent kernel is the Fisher sensitivity kernel, the infinite-width Gaussian limit is the Gaussian-process emulator, and the lazy-to-feature transition is the validity boundary of a reduced-basis emulator. I then test the open export on a truncated attention map, a token-level transfer operator, and a sparse expert router, and report a mostly negative result. The conserved flux ledger ports wherever openness is genuinely present, but its distinctive content is absent, an artifact of the chosen partition, or pinned near a floor by the training objective, and the operationally useful uncertainty turns out to be epistemic, living in the closed half of the correspondence, not the open one. The negative has a structural reason this note makes precise: the open case needs an eliminated sector with a continuous spectrum and wave-like, not relaxational, dynamics, which mainstream learning's finite or dissipative objects do not supply. This is a note, not a result; its main finding is that negative one, and its value is the map that locates it.
Subjects:
Machine Learning (cs.LG); Nuclear Theory (nucl-th); Computational Physics (physics.comp-ph); Data Analysis, Statistics and Probability (physics.data-an)
arXiv:
2606.09950 [pdf]
0 citations
13
[Submitted on 8 Jun 2026] (cross-list from hep-lat)
Momentum Dependence of Heavy Quark Diffusion in a Thermal Gluonic Plasma on the Lattice
Harshit Pandey🇮🇳 · Sayantan Sharma🇮🇳
We study the dynamics of a heavy quark in a thermal plasma consisting of non-perturbatively interacting soft momentum gluons at high temperatures, described in terms of an effective theory of QCD. Discretizing this effective field theory on a three-dimensional lattice, we propose a numerical strategy that allows us to simulate the dynamics of a heavy quark for different values of initial momenta and for a wide temperature range, higher than $480$ MeV. This allows us, for the first time, to extract the momentum dependence of the heavy quark drag and diffusion coefficients in a non-perturbatively interacting thermal, non-Abelian plasma.
Comments:
v2; few typos corrected; figures updated
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2606.10049 [pdf]
0 citations
14
[Submitted on 8 Jun 2026] (cross-list from astro-ph.HE)
Internal constitution of the outer crust of non-accreted neutron stars and magnetars
Juliette Servais · Nicolas Chamel
Context. Determining the internal constitution of the outer crust of magnetars is important for interpreting several of their astrophysical manifestations. In particular, the crustal composition is a key input for simulations of r-process nucleosynthesis in giant flare ejecta. However, traditional methods are computationally expensive, limiting their use in large-scale studies. Although faster iterative approaches exist, they are restricted to unmagnetized matter and strongly quantizing magnetic fields, leaving the intermediate field strengths characteristic of observed magnetars without an efficient treatment. Aims. We developed the program magcrust to extend these existing iterative approaches, enabling the rapid computation of the outer-crust composition of cold, non-accreted magnetars over the full range of the magnetic-field strengths inferred for these objects. Methods. Transitions between adjacent crustal layers are computed by solving approximate equilibrium conditions at the interface. Nuclear abundances and layer depths are estimated from approximate solutions of Einstein's equations of general relativity. Results. The performance and accuracy of the program were assessed against detailed numerical calculations. Relative deviations from exact transition properties remain within a few percent, and crustal compositions are well reproduced across 17 nuclear mass tables and 1300 magnetic-field strengths from 1E13 to 1E16 G. Computation times are reduced by factors of 1E3-1E7 compared to traditional approaches. Conclusions. This program provides a robust and efficient tool for determining the stratification of magnetars' outer crust over the full range of astrophysically relevant magnetic-field strengths. Its computational speed makes it well suited to systematic calculations, including sensitivity analyses, uncertainty quantification, and ensemble studies.
Comments:
9 pages, 2 figures. Accepted for publication in Astronomy & Astrophysics
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2606.10118 [pdf]
Astron.Astrophys.(2026)·0 citations
15
[Submitted on 9 Jun 2026] (cross-list from hep-ph)
Light and Strange Baryons in Medium
T. Massimino🇺🇸 · T. Klähn🇺🇸 · Z. Papp🇺🇸
We solve the Goldstone-boson-exchange (GBE) relativistic constituent quark model of light and strange baryons by using the Faddeev approach. The model reproduces the vacuum mass spectrum of light and strange baryons below $2$ GeV reasonably well. To test the sensitivity of the model to possible medium-induced effects, we vary the masses of the constituent quarks and the exchange bosons, the confinement strength, and the quark-meson coupling constant. In a parametric study, we consider a set of power law scaling relations for these parameters, including some motivated by constituent quark level current algebra relations. We find that the baryon spectrum is most sensitive to the quark-meson coupling constant, and generally observe a decrease in baryon mass with decreasing constituent quark mass. We qualitatively estimate the impact of these mass shifts on ideal-gas baryon yields and yield ratios. Absolute yields can change significantly already for mass shifts of a few $10$ ~MeV, whereas yield ratios are strongly modified only when the compared baryons have different constituent-quark-mass dependence.
Comments:
10 pages
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2606.10356 [pdf]
0 citations
16
[Submitted on 9 Jun 2026] (cross-list from hep-ex)
$Λ$ (1520) as a probe of resonance-driven deuteron formation at the LHC
Sushanta Tripathy🇸🇪 · Peter Christiansen🇸🇪
Light nuclei such as deuterons are produced abundantly in high-energy proton-proton and nuclear collisions despite their tiny binding energies. Their production mechanism remains unresolved, as both nucleon coalescence and statistical thermal models reproduce inclusive LHC yields. We propose a direct invariant-mass observable that discriminates between these scenarios using the long-lived $Λ (1520) \to pK$ resonance. If decay protons coalesce into deuterons, the produced nuclei remain correlated with the kaon, allowing the resonance peak to be reconstructed experimentally through proxy masses, $M_{(d/2) K}$ , formed from kaons and half the deuteron four-momentum. Using Thermal-FIST and PYTHIA with a deuteron coalescence afterburner, we show that a $M_{(d/2) K}$ peak emerges only in the coalescence scenario. This observable provides a direct experimental probe of resonance-fed deuteron production and of late-stage coalescence dynamics in high-energy collisions.
Comments:
5 pages and 4 captioned figures
Subjects:
High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2606.10668 [pdf]
1 citation
17
[Submitted on 9 Jun 2026] (cross-list from hep-th)
Chiral Plasma under Strong Magnetic Fields: A Holographic Analysis of Transport Phenomena
Michael Lublinsky🇮🇱 · Hadas Tzarfati🇮🇱
Chiral plasma appears in several areas of physics, historically starting from primordial plasma in the early Universe, then in quark-gluon plasma produced in heavy ion collisions, and, more recently, in Dirac and Weyl semimetals. The major signature of the plasma is the non-conservation of the axial current due to the chiral anomaly and the emergence of new, anomaly-induced transport phenomena. In this paper, we study the plasma exposed to arbitrarily strong constant magnetic and weak electric fields. Employing all-order gradient resummation, we write down constitutive relations for electric and axial currents parameterized by thirteen momentum- and magnetic- field-dependent transport coefficient functions. The latter are computed utilizing a theoretical lab for a realistic plasma, namely a holographic $U (1)_{V} \times U (1)_{A}$ Maxwell--Chern--Simons theory in Schwarzschild--AdS $_{5}$ , in the probe limit. As an application, we revisit the phenomena of negative magnetoresistance and chiral magnetic waves, beyond the naive hydrodynamic limit.
Comments:
36 pages
Subjects:
High Energy Physics — Theory (hep-th); cond-mat.mtrl-sci (cond-mat.mtrl-sci); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2606.10689 [pdf]
0 citations
18
[Submitted on 9 Jun 2026] (cross-list from nucl-ex)
Hindered $Δ K = 1$ Dipole Strength in octupole bands in $N = 90$ $^{154}$ Gd from Lifetime Measurements with $γ - γ$ fast timing technique
A. Pal🇮🇳 · S. Basak🇮🇳 · D. Kumar🇮🇳 · T. Bhattacharjee🇮🇳 · B. Maheshwari🇮🇳 · K. Nomura🇯🇵 · P. Van Isacker🇫🇷 · D. Banerjee🇮🇳 · S. S. Alam🇮🇳 · A. K. Jain🇮🇳
The lifetimes of the low-lying negative-parity $1^{-}$ state at 1414~keV and $2^{-}$ state at 1398~keV in $^{154}$ Gd have been measured using the $γ$ -- $γ$ fast-timing technique with the VENTURE array at VECC, Kolkata. The states were populated through the $β$ decay of $^{154}$ Tb, produced in proton-induced reactions at the K130 cyclotron. From the measured lifetimes, absolute $B (E 1)$ transition strengths were deduced. The extracted $B (E 1)$ values are compared with those of neighboring Gd isotopes and with Gogny-HFB-based $s df$ -IBM calculations. The results show that the measured $E 1$ strengths from these states are strongly hindered compared with the corresponding $Δ K = 0$ transitions, providing evidence for weak $Δ K = 1$ dipole strength in $^{154}$ Gd.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2606.11143 [pdf]
0 citations

Affiliations

first authorsco-authorsvia INSPIRE