Nuclear Theory·nucl-th

Friday·June 19, 2026

9 papers—3 primary·6 cross-listed

01
Parameter-free deformation variables of the proxy-SU(3) symmetry in even-even actinide, superheavy and hyperheavy nuclei with Z=82-126, N=82-258
Dennis Bonatsos · V. K. B. Kota · Andriana Martinou · S. K. Peroulis · D. Petrellis · P. Vasileiou · T. J. Mertzimekis · N. Minkov
Superheavy and hyperheavy nuclei are one of the frontiers of nuclear structure nowadays, while also for many actinides rather limited experimental information exists. Therefore, theoretical methods providing parameter-independent predictions for these nuclei are of particular interest. Such a method is the proxy-SU(3) approximation to the shell model, which has been adequately tested against experimental data in medium-mass and heavy nuclei up to the rare earth region, and has been found to provide reliable, parameter-independent predictions for the collective deformation variables beta and gamma. Within the proxy-SU(3) approach, the SU(3) symmetry of the 3-dimensional harmonic oscillator, which is destroyed beyond the sd shell by the strong spin-orbit interaction, is restored through a unitary transformation. For each nucleus, the most symmetric irreducible representation (irrep) allowed by the Pauli principle and the short-range nature of the nucleon-nucleon interaction, called the highest-weight (hw ) irrep in mathematical language, is found to suffice, except in cases in which the hw irrep turns out to be completely symmetric, so that the next highest weight (nhw) irrep has also to be included. In this article we provide a full collection of the hw and nhw irreps, as well as of the corresponding parameter-free predictions for the deformation variables beta and gamma, for all atomic nuclei ranging from Z=82, N=82 to Z=126, N=258. Several cases exemplifying the use of the collected results for studying the prolate to oblate shape transition, mirror symmetries, as well as the evolution of the collective variables along the valley of stability are also considered.
nucl-thSymmetry(2026)·0 citations
02
Hybrid stars with hyperons: structure based on QCD sum rule coupling constants
F. Moradi Jangal🇮🇷 · H. R. Moshfegh🇮🇷 · K. Azizi🇮🇷
We present a comprehensive study of hybrid stars composed of hadrons, leptons, and quarks within a relativistic mean-field framework. Using coupling constants derived from QCD sum rules (QCDSR), we first determine the bulk properties of nuclear matter and evaluate the single-particle potentials of nucleons and hyperons to constrain the hadronic sector. The equation of state (EOS) under beta equilibrium is then constructed employing the $σ - ω - ρ$ model for the hadronic phase, while the quark phase is described using both the MIT bag model and the Nambu-Jona-Lasinio (NJL) model. The hadron-quark phase transition is analyzed through both Gibbs and Maxwell constructions. Based on resulting EOSs, we obtain the mass-radius relations of hybrid stars, investigate particle fractions and their radial distributions, and calculate the tidal Love number ( $K_{2}$ ) and the dimensionless tidal deformability ( $Λ$ ). Our results provide quantitative predictions relevant for comparison with current multimessenger astrophysical observations.
nucl-thastro-ph.HEastro-ph.SRhep-ph0 citations
03
Trace anomaly and interior curvature of neutron stars in energy-momentum squared gravity
Ratikanta Swain🇮🇳 · Sayantan Ghosh🇮🇳 · Bharat Kumar🇮🇳
In energy-momentum squared gravity (EMSG), the spacetime inside a neutron star is sourced by effective thermodynamic variables that need not coincide with the physical fluid pressure and energy density. It is therefore an open question whether the trace anomaly of dense matter -- the QCD measure of how strongly conformal symmetry is broken -- still organizes interior profiles and curvature in the same way it does in general relativity (GR). We adopt a clear matter-geometry separation: the trace anomaly is computed from the fluid sector alone, while spacetime curvature scalars are built from the variables that actually source the modified Tolman-Oppenheimer-Volkoff equations. For five relativistic mean-field equations of state, the radial trace-anomaly profiles increase monotonically from core to surface in all accepted EMSG models, as in GR, but split systematically with the EMSG coupling strength; the splitting grows with stellar compactness. Despite this deformation, curvature invariants still fall onto organized bands when plotted against the trace anomaly, extending the GR thermodynamic-geometric correspondence. The Ricci contraction shows the tightest organization, whereas the Ricci scalar remains the most equation-of-state sensitive. EMSG effects are modest for observationally accessible stars but largest in stiff, ultracompact configurations, indicating that the trace anomaly remains a useful thermodynamic label for interior geometry even when gravity couples nonlinearly to matter.
nucl-thgr-qchep-ph1 citation
04
Self-Calibration of the Neutrino-Argon Cross Section with Solar Neutrinos
Rasmi Hajjar🇺🇸 · Obada Nairat🇺🇸 · John F. Beacom🇺🇸
The success of DUNE's MeV physics program depends upon high-precision knowledge of the charged-current (CC) $ν_{e} +^{40} Ar$ cross section. While there are indirect constraints at the 10% level for the nuclear transitions that constitute this cross section, the only direct measurement in the MeV range has an uncertainty of $\sim$ 50%. We show, surprisingly, that the cross section can be precisely measured using the solar-neutrino data themselves. This is possible because of independent knowledge of the $^{8}$ B flux and survival probability, plus the distinctive angular distributions of the Fermi and Gamow-Teller transitions that comprise the cross section. We propose new methods to extract the transition strengths, considering both intuitive groupings and a Principal Component Analysis. Under pessimistic assumptions about detection, but taking detector uncertainties to be controlled, we demonstrate that a precision of $≲$ 2% on the cross section can be achieved in the 9-15 MeV energy range. These results will be an important foundation for studying the cross section up to several tens of MeV, where the complexity increases significantly due to nuclear breakup channels but where reducing uncertainties is critical for supernova and atmospheric neutrino studies.
↳ hep-phhep-exnucl-exnucl-th0 citations
05
Scalar diquark mass and quark--diquark potential from lattice QCD using the potential method with a static quark
Kai-Wen Kelvin-Lee🇯🇵 · Noriyoshi Ishii🇯🇵
We study the scalar diquark mass and the quark--diquark potential by applying a HAL QCD-inspired potential method to a baryonic system composed of a scalar diquark and a static quark. The diquark mass is determined self-consistently by requiring that the p-wave baryonic spectrum obtained from two-point correlators be reproduced within the potential framework. Numerical calculations are performed using $2 + 1$ flavor QCD gauge configurations generated by the PACS-CS Collaboration on a $L^{3} \times T = 3 2^{3} \times 64$ lattice with $a^{- 1} \approx 2.176$ GeV and the pion mass, $m_{π} \approx 702$ MeV. From the analysis, we obtain a scalar diquark mass which is close to the na\"ıve constituent quark estimate $(2/3) m_{N}$ , together with a quark--diquark potential of the Cornell type (Coulomb + linear). The string tension extracted from the quark--diquark potential agrees within approximately 5% with that obtained from the static quark--antiquark potential (Wilson Loop).
↳ hep-lathep-phnucl-th1 citation
06
Probing flavor effects in the QCD parton shower using $D^{0}$ -tagged jet angularities in proton $-$ proton collisions at $s = 5.02$ TeV
ALICE Collaboration
The ALICE Collaboration presents the first measurements of $D^{0}$ -tagged jet angularities in proton $-$ proton (pp) collisions at $s = 5.02$ TeV. Jet angularities are powerful substructure observables that characterize the angular and momentum distributions of particles within jets via tunable weighting parameters. Varying the angular parameter in jet angularities allows for a systematic probe of the sensitivity to collinear and soft radiation, enabling the study of flavor-dependent fragmentation and hadronization through comparisons of jets initiated by different partons. This paper reports $D^{0}$ -tagged and inclusive (gluon-dominated) charged-particle jet angularities with a resolution parameter $R = 0.4$ in the low jet transverse momentum range ( $10 < p_{T}^{ch. jet} < 20$ GeV/ $c$ ), where charm-quark mass effects are most significant. At low angular weight, which emphasizes collinear radiation, $D^{0}$ -tagged jets exhibit smaller angularity values than inclusive jets. This provides evidence for the radiation suppression from massive quarks -- a phenomenon known as the QCD dead-cone effect. As the angular weight increases, giving more emphasis to wide-angle radiation, the difference between $D^{0}$ -tagged and inclusive jet distributions decreases. This indicates that the modification is concentrated within the jet core rather than its edge. PYTHIA 8 simulations qualitatively reproduce both the angularity of $D^{0}$ -tagged and inclusive charged-particle jets, but reproduce the $D^{0}$ -tagged jet distributions better than those of inclusive jets, offering a powerful new constraint for models. These results provide insight into flavor-dependent fragmentation and establish an essential baseline for future studies of jet modifications in the quark-gluon plasma produced in heavy-ion collisions.
↳ nucl-exnucl-th0 citations
07
Toward Precision Fragmentation of $Ω_{3 Q}$ Baryons: The OMG3Q1.1 Framework
Francesco Giovanni Celiberto🇪🇸
Recent experimental advances in the baryon sector, including the observation of doubly charmed states, have renewed interest in the production mechanisms of increasingly heavy hadronic systems, calling for precision and uncertainty-controlled descriptions. We present the OMG3Q1.1 framework for the fragmentation of same-flavor all-heavy $Ω_{3 Q}$ baryons in high-energy hadronic collisions. The construction combines diquark-inspired inputs for constituent-heavy-quark and gluon channels with threshold-aware DGLAP evolution within the HF-NRevo scheme. A replica-based strategy consistently quantifies perturbative missing-higher-order effects (F-MHOUs) and nonperturbative wave-function uncertainties (F-NPWFs), yielding the first uncertainty-resolved fragmentation-function set for the $Ω_{3 Q}$ sector. The resulting LHAPDF6 grids are employed to investigate semi-inclusive $Ω_{3 Q}$ plus jet production at the HL-LHC and future FCC within the (sym)JETHAD environment. The OMG3Q1.1 framework establishes a precision-oriented baseline for rare triply heavy baryons and provides a foundation for future studies of the heavy-flavor baryon landscape.
↳ hep-phhep-exnucl-exnucl-th1 citation
08
Revisiting the role of saturation in diffractive vector meson production
Heikki Mäntysaari🇫🇮 · Hendrik Roch🇫🇮 · Björn Schenke🇺🇸 · Chun Shen🇺🇸 · Wenbin Zhao🇨🇳
We perform a global Bayesian analysis of coherent and incoherent diffractive $J / ψ$ photoproduction in $γ + p$ and $γ + Pb$ collisions using a Color Glass Condensate (CGC)-based framework and ultraperipheral collision data from the Large Hadron Collider (LHC), corrected for the expected effect of electromagnetic dissociation (EMD). Using Gaussian-process emulators of the underlying CGC calculations, we infer model parameters from a combined set of HERA and LHC measurements. We find that the $γ + Pb$ data with EMD correction substantially reduce the previously observed tension between proton and nuclear datasets, enabling a consistent simultaneous description of diffractive $J / ψ$ production in $γ + p$ and $γ + Pb$ collisions within the CGC framework.
↳ hep-phnucl-thPRD(2026)·3 citations
09
Rotating magnetized pion gas of finite transverse size: condensation constraints and transport properties
Ankit Kumar🇮🇳 · Diwakar Gaur🇮🇳 · Vinod Chandra🇮🇳
This work investigates the electric, thermal, and thermoelectric responses of a rotating pion gas of finite transverse radius in the presence of a background magnetic field, with the rotation axis aligned with the magnetic field. We explicitly calculate the parameter limits for $π^{+}$ condensation and restrict our working regime safely outside these boundaries, ensuring well-behaved transport coefficients. Notably, the system exhibits a condensation asymmetry, with $π^{-}$ remaining uncondensed at the parameters that induce $π^{+}$ condensation. Using the Boltzmann Transport Equation under the Relaxation Time Approximation, we calculate the longitudinal electrical conductivity, thermal conductivity, and the Seebeck coefficient. Our results reveal a competing interplay between the magnetic field and rotation, highlighting the substantial impact of rotation on the medium's transport properties: while the magnetic field suppresses the transport coefficients in a static medium, rotation, acting as an effective chemical potential, introduces an energy shift that favors their increase. Beyond an angular velocity, this rotational enhancement overpowers the magnetic suppression, leading to an increase in the transport coefficients with increasing magnetic field. Finally, we analyze the relative significance of charge and heat transport through the Lorenz number, providing further insight into the transport characteristics of the rotating magnetized pion medium.
↳ hep-phnucl-th1 citation

Affiliations

first authorsco-authorsvia INSPIRE