Nuclear Theory·nucl-th

Monday·May 25, 2026

6 papers—3 primary·3 cross-listed

01
Intertwined quantum phase transitions in the even-even $^{90 - 100}$ Sr isotopes
Noam Gavrielov
The even-even $^{90 - 100}$ Sr isotopes are identified as a region of intertwined quantum phase transitions (IQPTs). In this scenario, a quantum phase transition involving the crossing of normal and intruder configurations is accompanied by a shape evolution within the intruder configuration. Using the interacting boson model with configuration mixing (IBM-CM), we show that the strontium chain exhibits coexisting Type I and Type II QPTs, where the intruder configuration evolves from a near-spherical structure in $^{90 - 96}$ Sr to a deformed one in $^{98, 100}$ Sr, while the normal and intruder configurations cross between $^{96}$ Sr and $^{98}$ Sr. As a result, the ground state changes abruptly from a weakly collective normal configuration to a deformed intruder configuration. Evidence for this scenario is provided by a detailed comparison with experimental excitation energies, spectroscopic quadrupole moments, isotope shifts, and monopole $E 0$ transition strengths, together with the configuration and $n_{d}$ decompositions of the calculated wave functions. The results place the strontium isotopes alongside the neighboring zirconium chain as another realization of IQPTs in the intricate $A \approx 100$ region.
nucl-th1 citation
02
Quasiradial oscillations of rotating hybrid neutron stars
Zi-Yue Zheng🇨🇳 · Ting-Ting Sun🇨🇳 · Huan Chen🇨🇳 · Xiao-Ping Zheng🇨🇳 · Jin-Biao Wei🇨🇳 · G. F. Burgio🇮🇹 · H.-J. Schulze🇮🇹
We investigate fundamental quasiradial oscillations in slow-rotation approximation of pure and hybrid neutron stars, employing equations of state of nuclear matter from Brueckner-Hartree-Fock theory or the relativistic mean field model, and of quark matter from the Dyson-Schwinger quark model, performing a Gibbs construction for the mixed phase in hybrid stars. Characteristic differences between neutron-star and hybrid-star fundamental quasiradial oscillation frequencies during spin-down are pointed out.
nucl-thastro-ph.HE0 citations
03
Coulomb bridge mechanism for peripheral polarization of weakly bound projectiles
Hao Liu · Jin Lei · Zhongzhou Ren
We identify the matrix elements that carry peripheral polarization of weakly bound projectiles through the Feshbach dynamical polarization potential (DPP) within the continuum-discretized coupled-channels (CDCC) framework. Splitting the two P-Q bridge couplings into nuclear and Coulomb parts, while keeping a single Q-space propagator common to every term, decomposes the DPP into a nuclear, a Coulomb, and an interference component, $Δ U_{DPP} = Δ U_{N} + Δ U_{C} + Δ U_{N C}$ . Applied to $d +^{58}$ Ni, $^{6}$ Li $+^{208}$ Pb, $^{11}$ Be $+^{64}$ Zn, and $^{8}$ B $+^{64}$ Zn, the decomposition reveals a controlled hierarchy: a nuclear bridge in the light system, a mixed bridge with strong destructive interference in the heavy stable case, and a Coulomb-dominated bridge in both halo systems, with the proton halo showing constructive nuclear-Coulomb interference. For the halo reactions, peripheral partial waves ( $L ≳ 35$ ) satisfy $σ_{R}^{L} ≃ σ_{DPP}^{L} ≃ σ_{BU}^{L}$ , with the high- $L$ DPP tail dominated by $σ_{C}^{L}$ . Two diagnostic calculations isolate the responsible matrix elements: removing the off-diagonal Coulomb propagation inside Q leaves the pattern essentially intact, whereas removing the Coulomb part of the P-Q bridge collapses both DPP-induced absorption and breakup. The peripheral polarization of halo reactions is therefore a Coulomb-bridge effect, and the high- $L$ elastic-breakup yield serves as its observable signature.
nucl-th0 citations
04
Enhanced Stellar Production of Weakly Interacting Slim Particles from Non-Thermal Nuclear Cascades
Víctor Fonoll🇪🇸 · Maurizio Giannotti🇪🇸 · Giuseppe Lucente🇺🇸
Weakly interacting slim particles (WISPs) can be produced in stars through the conversion of non-thermal photons generated in nuclear reactions. Previous studies have generally treated these sources only at the level of their primary injection lines. We show that this picture is incomplete: repeated Compton scatterings redistribute the injected photons into a broad low-energy spectrum, while associated positrons can thermalize and annihilate into a 511~keV line. Together, these effects define a generic non-thermal photon reservoir and thus a broadly applicable source term for any photon-coupled WISP. We develop a general framework for this mechanism and illustrate its impact with the example of dark-photon production in the solar pp chain. Our results show that non-thermal stellar WISP production can be substantially underestimated if Compton reprocessing and positron annihilation are neglected.
↳ hep-phastro-ph.HEastro-ph.SRnucl-th0 citations
05
Observation of Entanglement Enabled Spin-Interference in the Drell-Söding Process in Au+Au Ultraperipheral Collisions at RHIC
The STAR Collaboration
We report a measurement of the Drell-Söding $π^{+} π^{-}$ production in Au + Au ultraperipheral collisions at a center-of-mass energy per nucleon pair $s_{N N} = 200 GeV$ using the STAR detector. For the first time, the Entanglement Enabled Spin-Interference (EESI) effect is observed in the Drell-Söding process through the amplitude $A_{2Δ ϕ}$ of the $cos (2Δ ϕ)$ modulation. The measured $A_{2Δ ϕ}$ exhibits no significant dependence on the invariant mass $M_{π^{+} π^{-}}$ . An enhancement of three standard deviations is observed for the Drell-Söding process compared to $ρ^{0}$ photoproduction. Furthermore, we measure the $∣ t ∣$ -dependence of the Drell-Söding process and $ρ^{0}$ photoproduction. The Drell-Söding spectrum falls more steeply with $∣ t ∣$ and exhibits diffractive structures shifted to lower $∣ t ∣$ compared to $ρ^{0}$ photoproduction, features that are not captured by theoretical calculations. These results provide new insights into the interplay between quantum interference and photon-nuclear interactions in ultra-peripheral heavy-ion collisions.
↳ nucl-exnucl-th1 citation
06
Probing nuclear interactions à la Rutherford: Insights on $^{4}$ He from $α$ scattering
F. Cappuzzello · V. Soukeras · S. Bacca · D. Carbone · M. Cavallaro · L. C. Chamon · I. Lombardo · G. Orlandini · M. Viviani · C. Agodi · H.-W. Becker · G. A. Brischetto and 18 other authors
Nuclear interactions play a key role for the stability of atomic nuclei and stellar environments. Successful parametrization and models of these interactions, developed in the last decades, accurately reproduce all the proton and neutron scattering data, besides the properties of few-body nuclear systems. However, recent electron scattering results focusing on the first excited resonant state of $^{4}$ He nucleus, reveal a puzzling situation suggesting potential gaps in our understanding of the nuclear phenomenology. Here, we report a new study of such $^{4}$ He resonance by $^{4}$ He + $^{4}$ He scattering featuring data of unprecedented sensitivity and state-of-art analyses of the spectral line shape together with a phenomenological reaction modeling that incorporates the same nuclear densities employed in electron-scattering studies. Our analysis of the full set of experimental observables yields a reasonable description within the framework of current nuclear-interaction physics, thereby highlighting the need for further advancing the modeling of few-body open quantum systems.
↳ nucl-exnucl-thNature Commun.(2026)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Intertwined quantum phase transitions in the even-even 90−100Sr isotopes

Quasiradial oscillations of rotating hybrid neutron stars

Coulomb bridge mechanism for peripheral polarization of weakly bound projectiles

Enhanced Stellar Production of Weakly Interacting Slim Particles from Non-Thermal Nuclear Cascades

Observation of Entanglement Enabled Spin-Interference in the Drell-Söding Process in Au+Au Ultraperipheral Collisions at RHIC

Probing nuclear interactions à la Rutherford: Insights on 4He from α scattering

Affiliations

Intertwined quantum phase transitions in the even-even $^{90 - 100}$ Sr isotopes

Probing nuclear interactions à la Rutherford: Insights on $^{4}$ He from $α$ scattering