Nuclear Theory·nucl-th

Wednesday·March 18, 2026

10 papers—5 primary·5 cross-listed

01
Baryon fluctuation signatures of the onset of deconfinement
Marek Gazdzicki🇵🇱 · Mark Gorenstein🇺🇦 · Anar Rustamov🇩🇪
An anomalous collision-energy dependence of proton number fluctuations is predicted as a consequence of the onset of deconfinement in heavy-ion collisions at the center of mass energy of the nucleon pair of about 10 GeV. The effect arises from changes in the effective degrees of freedom between confined and deconfined matter. This may provide a natural explanation of the recent beam-energy-scan results on proton number fluctuations at the BNL RHIC and offers a consistent interpretation of data from the CERN SPS and RHIC experiments in terms of the onset of deconfinement.
nucl-thhep-phnucl-ex0 citations
02
Scaled transverse-momentum spectra as a probe of collective dynamics in heavy-ion collisions
Thiago S. Domingues · Matthew Luzum
We investigate a scaling property of transverse-momentum spectra in ultrarelativistic heavy-ion collisions obtained by removing the global scales of multiplicity and mean transverse momentum. The resulting dimensionless observable isolates the intrinsic shape of the spectrum and reveals an approximate universality across collision centralities, systems, and energies. Hydrodynamic simulations reproduce this scaling on an event-by-event basis, indicating that it may originate from the collective dynamics of the quark-gluon plasma. Using Gaussian-process emulators trained on the JETSCAPE hybrid model, we perform a Bayesian analysis incorporating the scaled spectra as observables. The results demonstrate that the spectral shape provides independent constraints on key properties of the medium, including pre-equilibrium dynamics and initial-state granularity, while exposing tensions with parameter regions preferred by traditional $p_{T}$ -integrated observables. We further explore an analogous scaling of transverse-mass spectra and observe a comparable universality across centralities and hadron species. These results suggest that scaled spectra provide a powerful new probe of collective dynamics and offer complementary constraints for the quantitative characterization of QCD matter created in heavy-ion collisions.
nucl-thhep-phhep-th1 citation
03
Sensitivity of neutron star observables to microscopic nuclear parameters of realistic equations of state
Nikolas Cruz-Camacho🇺🇸 · Carlos Conde-Ocazionez🇺🇸 · Veronica Dexheimer🇺🇸 · Jacquelyn Noronha-Hostler🇺🇸 · Nicolás Yunes🇺🇸
The equation of state of matter at supranuclear densities governs the astrophysical observables of neutron stars. A realistic, though complex, description is provided by the Chiral-Mean-Field model, which depends on many microscopic nuclear-physics parameters. We present a Fisher-information-inspired analysis of the sensitivity of neutron-star observables to the parameters of the Chiral-Mean-Field model at $β$ -equilibrium using SLy as a crust. We then compute neutron-star sequences and extract masses, radii, compactnesses, and tidal deformabilities. From the logarithmic derivatives of these observables with respect to each nuclear parameter, we construct a dimensionless, Fisher-inspired sensitivity matrix and perform a principal-component analysis to identify the effective combinations of nuclear parameters that most strongly affect neutron-star observables. Although the ranking depends mildly on the observable, the three most important nuclear parameters are the vacuum value of the dilaton field $χ_{0}$ (which sets the overall scale of the scalar potential and trace-anomaly contribution), the scalar singlet strength $g_{1}^{X}$ (which controls the overall scalar attraction through the baryon effective masses), and the $k_{0}$ quadratic scalar term (which governs the curvature of the scalar potential). This framework provides a reproducible, data-driven approach to quantify parameter sensitivities in dense-matter models and to guide future Bayesian inference of nuclear information from multi-messenger astrophysical observations.
nucl-thastro-ph.HEgr-qchep-ph2 citations
04
Prediction of Alpha-Decay Half-Lives of Actinide Nuclei Using the DDM3Y Effective Interaction Potential
N.Sowmya · H.C.Manjunatha · Roshini.K.N · R.S.Susheela
The prediction of nuclear half-lives is vital for understanding nuclear stability with significant applications in astrophysics, nuclear energy, and medical physics. This study investigates the $α$ -decay half-lives of 154 actinide nuclei in the atomic number range $89 \leq Z \leq 103$ using the Density-Dependent M3Y (DDM3Y) effective interaction potential. The theoretical framework utilizes a double-folding model where the densities of the $α$ -particle and the daughter nucleus are folded to derive the nuclear interaction potential.Theoretical half-lives were calculated using the WKB approximation and compared against experimental data and established semi-empirical models, including the Viola-Seaborg (VSS), CPPM, GLDM, and ELDM frameworks. The DDM3Y model demonstrates a systematically improved agreement with experimental half-lives across the actinide series, effectively capturing the inverse correlation between $Q$ -values and decay times. Statistical analysis yielded a standard deviation of 1.76, confirming the reliability of this approach for predicting the stability and decay properties of heavy and new isotopes.
nucl-th0 citations
05
Nuclear pasta in hot neutron-star matter and proto-neutron stars
Jian Zhou · Junbo Pang · Hong Shen · Jinniu Hu
We investigate nuclear pasta phases appearing in hot neutron-star matter based on the compressible liquid-drop model, where the matter consists of a dense liquid phase and a dilute gas phase separated by a sharp interface. The surface tension is calculated self-consistently from the Thomas-Fermi approximation, and it depends on temperature and isospin asymmetry. We employ relativistic mean-field models with different symmetry energy slopes to describe nuclear interactions. It is found that the TM1e model with a small symmetry energy slope of $L = 40$ MeV predicts various pasta shapes at low temperatures, while the TM1 model with $L = 110.8$ MeV yields only the droplet configuration up to the crust-core transition density. We examine the occurrence and influence of pasta phases in proto-neutron stars with a constant entropy per baryon. These pasta phases may occur in the inner crust with a thickness of about $1.2$ km, playing an important role in the thermal evolution of the star.
nucl-thastro-ph.HE0 citations
06
Strangeness neutrality and the QCD phase diagram
Wei-jie Fu🇨🇳 · Chuang Huang🇩🇪 · Jan M. Pawlowski🇩🇪 · Fabian Rennecke🇩🇪 · Rui Wen🇨🇳 · Shi Yin🇩🇪
We map out the phase structure of $N_{f} = 2 + 1$ flavour QCD at strangeness neutrality with functional QCD. We find a critical end point at $(T_{CEP}, μ_{B, CEP}) ∣_{n_{S} = 0} = (92, 696)$ \,MeV. The computation is done with the functional renormalisation group, and we systematically improve on previous works, hence reducing the systematic error significantly. Our results pass relevant QCD benchmarks: they agree well with and corroborate the QCD phase structure from functional QCD results at vanishing strangeness chemical potential. Moreover, they agree well with lattice QCD results at vanishing chemical potential. Specifically, the ratio of the second order curvature coefficient $κ_{2}$ agrees with that obtained from lattice computations, $κ_{2} (n_{S} = 0) / κ_{2} (μ_{S} = 0) = 0.897 (20)$ .
↳ hep-phhep-exnucl-exnucl-th13 citations
07
Polarization-dependent mass modifications of $ϕ$ meson with finite momentum in nuclear matter
Ahmad Jafar Arifi🇯🇵 · Philipp Gubler🇯🇵 · Kazuo Tsushima🇧🇷
We investigate the in-medium properties of the $ϕ$ meson with finite momentum, going beyond the commonly studied case at rest. In a nuclear medium, Lorentz invariance is broken, leading to distinct longitudinal and transverse polarization modes that evolve differently with density and momentum. Within an effective Lagrangian approach, we calculate the polarization-dependent mass shifts and width modifications of the $ϕ$ meson arising from $K K ˉ$ loops and mean-field interactions. The divergent loop integrals are regulated using two different schemes: a covariant form factor and dimensional regularization. Our results show that the mass shift of the transverse polarization is independent of the $ϕ$ -meson momentum, whereas that of the longitudinal polarization decreases quadratically with momentum. This difference originates from the coupling of the longitudinal mode to the vector mean field and derivative-type interactions in the self-energy. These effects have direct implications for experimental observables, especially for upcoming measurements at J-PARC, and provide a new prediction for experiments studying hadron dynamics in dense matter.
↳ hep-phnucl-thPRD(2026)·2 citations
08
Lattice QCD at finite temperature and density
Heng-Tong Ding🇨🇳
I review recent lattice results on strongly interacting matter under extreme conditions, with emphasis on the finite-temperature QCD transition at $μ_{B} = 0$ , its approach toward the chiral limit and the fate of the $U_{A} (1)$ anomaly, as well as recent constraints on the QCD phase boundary and the possible critical endpoint at $μ_{B} > 0$ . I also discuss selected advances in lattice methods and in QCD thermodynamics under external conditions, in particular strong magnetic fields, isospin chemical potential, rotation, acceleration, and quark spin polarization.
↳ hep-lathep-phhep-thnucl-ex+15 citations
09
Fission mode identification in the 180Hg region: derivative analysis approach
D. T. Kattikat Melcom🇫🇷 · I. Tsekhanovich🇫🇷 · F. Guezet🇫🇷 · A. Andreyev🇬🇧 · K. Nishio🇯🇵
Experimental setups commonly used to study fission properties of nuclei in the exotic neutron-deficient 180Hg region are based on the time-of-flight technique for the fission-product identification. The nuclei of interest are created via fusion reactions at excitation energies of several tens of MeV and identified with limited mass resolution. The deduced final fission-fragment mass distributions are in general structureless, which makes the identification of fission modes, along with their properties, ambiguous and author-dependent. The standard functional-analysis technique applied to the simulated limited-resolution fusion-fission data appears to provide consistent results on the number and parameters of fission modes, even in cases of strong symmetric-mode dominance, i.e. for Gaussian-like fission-fragment mass distribution shapes. The method is shown to work also on data sets with limited statistics (real experimental data with integral of a few tens of thousands of events).
↳ nucl-exnucl-thPRC(2026)·0 citations
10
Finite size effects on critical correlations in momentum space
Athanasios Brofas🇬🇷 · Fotios K. Diakonos🇬🇷
The search for the QCD critical end point (CEP) is a major objective of contemporary heavy-ion physics, motivating the study of fluctuation observables that are sensitive to critical dynamics. In particular, baryon-number fluctuations provide a natural probe because the net-baryon density can serve as an effective order parameter in the vicinity of the CEP. Near criticality, long-range correlations and power-law scaling are expected to emerge in the real-space two-point function of the baryon density, yet the finite size and finite lifetime of the fireball created in heavy-ion collisions impose intrinsic cutoffs that regulate the growth of the correlation length. These finite-size constraints significantly modify the observable structure of fluctuations, especially in momentum space, where experiments perform measurements. In this work we present a theoretical analysis of the momentum-space two-point correlation function for a system of finite spatial extent. We show that finite size effects lead to an effective scaling exponent which coincides with that of the infinitely extended system only in a prescribed scaling region within the experimentally accessible momentum range.
↳ hep-phhep-exnucl-exnucl-th1 citation

Affiliations

first authorsco-authorsvia INSPIRE