Nuclear Theory·nucl-th

Tuesday·July 29, 2025

13 papers—7 primary·6 cross-listed

01
Nuclear Schiff moment of fluorine isotope $^{19}$ F
Kia Boon Ng🇨🇦 · Stephan Foster🇨🇦 · Lan Cheng🇺🇸 · Petr Navratil🇨🇦 · Stephan Malbrunot-Ettenauer🇨🇦
Nuclear Schiff moments (NSMs) are sensitive probes for physics beyond the Standard Model of particle physics, signaling violations of time-reversal and parity-inversion symmetries in atomic nuclei. In this Letter, we report the first-ever calculation of a NSM in a nuclear ab initio framework, employing the no-core shell model to study the fluorine isotope $^{19}$ F. We further perform quantum-chemistry calculations to evaluate the sensitivity of the hafnium monofluoride cation, HfF $^{+}$ , to the NSM of $^{19}$ F. Combined with recent high-precision measurements of the molecular electric dipole moment of HfF $^{+}$ , our results enable the first experimental bound on the NSM of $^{19}$ F. Although the resulting bounds on the pion-nucleon-nucleon ( $π$ NN) coupling constants are not yet the most stringent, this work establishes the foundation for constraining $π$ NN interactions using nuclear ab initio methods.
nucl-thphysics.atom-phphysics.comp-phPRL(2026)·8 citations
02
Existence of a fourth Airy elephant in the nuclear rainbows for $^{12}$ C+ $^{12}$ C scattering
S. Ohkubo · Y. Hirabayashi
The number of gross structures in the 90 $^{\circ}$ excitation function for $^{12}$ C+ $^{12}$ C elastic scattering, often called Airy elephants, has been of great interest. These structures are caused by refractive scattering and are separated by Airy minima. Their importance stems from their close relationship to the interaction potential between two $^{12}$ C nuclei, which also describes the molecular resonances of the compound system at lower energies. Although a unique deep potential was usually determined from rainbow scattering at higher energies, a puzzling discrepancy persisted: the energy at which the Airy minimum $A 1$ crosses 90 $^{\circ}$ was $E_{c . m .} \approx$ 67 MeV for $^{12}$ C+ $^{12}$ C. This is remarkably low compared to approximately 100 MeV for both the $^{16}$ O+ $^{12}$ C and $^{16}$ O+ $^{16}$ O systems. This question remained unanswered until the discovery of the secondary rainbow in the $^{12}$ C+ $^{12}$ C system. We report for the first time that the highest energy at which the dynamically generated Airy minimum of the secondary rainbow crosses 90 $^{\circ}$ is about 100 MeV. This demonstrates that the fourth Airy elephant exists between the Airy minimum $A 1$ of the primary nuclear rainbow and that, $A 1^{(S)}$ , of the secondary rainbow. The long-standing problem concerning the Airy minima and Airy elephants has finally been resolved after decades of concern by recognizing the existence of a dynamically generated secondary rainbow in $^{12}$ C+ $^{12}$ C scattering.
nucl-thEPJA(2025)·1 citation
03
Nonlinear causality of Israel-Stewart theory with diffusion
Ian Cordeiro🇺🇸 · Fábio S. Bemfica🇺🇸 · Enrico Speranza🇮🇹 · Jorge Noronha🇺🇸
We present the first fully nonlinear causality constraints in $D = 3 + 1$ dimensions for Israel-Stewart theory in the presence of energy and number diffusion in the Eckart and Landau hydrodynamic frames, respectively. These constraints are algebraic inequalities that make no assumption on the underlying geometry of the spacetime or the equation of state. In order to highlight the distinct physical and structural behavior of the two hydrodynamic frames, we discuss the special ultrarelativistic ideal gas equation of state considered in earlier literature in $D = 1 + 1$ dimensions, and show that our general $D = 3 + 1$ constraints reduce to their results upon an appropriate choice of angles. For this equation of state in both $D = 1 + 1$ and $D = 3 + 1$ dimensions one can show that: (i) there exists a region allowed by nonlinear causality in which the baryon current transitions into a spacelike vector in the Landau frame, and (ii) an analogous argument shows that the solutions of the Eckart frame equations of motion never violate the dominant energy condition, assuming nonlinear causality holds. We then compare our results with those from linearized Israel-Stewart theory and show that the linear causality bounds fail to capture the new physical constraints on energy and number diffusion that are successfully obtained through our nonlinear causality approach.
nucl-thastro-ph.HEgr-qchep-phPRD(2026)·9 citations
04
Vibrational Modes in Strongly Deformed Nuclei
Y. Tsunoda🇯🇵 · T. Otsuka🇯🇵 · N. Shimizu🇯🇵 · T. Duguet🇫🇷 · Y. Utsuno🇯🇵 · T. Abe🇯🇵
Low-energy vibrational excitations associated with the fluctuation of quadrupole deformed shapes are discussed within the frame of state-of-the-art Configuration Interaction calculations, actually performed via the Quasi-particle Vacua Shell Model version of the Monte Carlo Shell Model. Recently, low-lying $γ$ bands in heavy strongly deformed nuclei were shown to be rotational $K^{P}$ = 2 $^{+}$ excitations of triaxially deformed states (see T. Otsuka \etal, Eur. Phys. J. A 61, 126 (2025)) rather than vibrational excitations as traditionally interpreted. In this context, it is important to identify possible low-lying vibrational excitations and to characterize the excitation energy at which they emerge. Focusing on two typical examples, $^{166}$ Er and $^{162}$ Dy, vibrational states are indeed identified above the $γ$ band using an extended version of the so-called T-plot. The phenomenon of shape coexistence is also shown to produce low-lying states below such vibrational band heads. These results suggest novel and rich structures in heavy deformed nuclei. While experimental counterparts are seen for some of such states, others are predictions opening doors to future dedicated experiments.
nucl-thnucl-ex3 citations
05
Understanding the correlation between elliptic and triangular flow
Mubarak Alqahtani🇸🇦 · Jean-Yves Ollitrault🇫🇷
The relative correlation between the magnitudes of elliptic flow ( $v_{2}$ ) and triangular flow ( $v_{3}$ ) has been accurately measured in nucleus-nucleus collisions at the LHC collider. As a function of the centrality of the collision, it changes sign and varies non-monotonically. We show that this is naturally explained by two combined effects. The first effect is a skewness in initial-state fluctuations, which is quantified by the correlation between the geometry-driven elliptic deformation in the reaction plane and the fluctuation-driven triangularity $ε_{3}$ . We introduce an intensive measure of this skewness, which is generically of order unity and depends weakly on the system size and centrality. We evaluate its magnitude using Monte Carlo simulations of the initial state, which show that it is sensitive to the nucleon width. The second effect is the fluctuation of impact parameter relative to centrality classifiers used by experiment. The ATLAS collaboration uses two different centrality classifiers, the multiplicity $N_{c h}$ and the transverse energy $E_{T}$ . We fit both sets of results for Pb+Pb collisions up to $\approx 40%$ centrality with a single parameter, the intensive mixed skewness. Its value inferred from experiment agrees with theoretical expectations.
nucl-thhep-exhep-phnucl-exPLB(2026)·2 citations
06
Single-flavor heavy baryons in a strong magnetic field
Gaoqing Cao🇨🇳 · Shuang Wu🇨🇳
In this work, we study the properties of single-flavor heavy baryons, $Ω_{ccc}$ and $Ω_{bbb}$ , in a strong magnetic field. For that sake, we simply treat the baryons as quark-diquark two-body systems, and a systematic formalism is developed to deal with two-body Schr $o ¨$ dinger equations in a magnetic field. It is found that: 1. The orbital properties of $Ω_{bbb}$ are almost not affected by the magnetic field. 2. $Ω_{ccc}$ is more tightly bound in the presence of a magnetic field. 3. The magnetic-spin effect dominates over the magnetic-orbital effect. Applying to peripheral heavy ion collisions, $Ω_{ccc}$ is much better than $Ω_{bbb}$ to explore the magnetic effect, and the discovery of $Ω_{ccc}$ could be more promising.
nucl-thhep-phPRD(2025)·2 citations
07
Impact of ground-state correlations on the multipole response of nuclei: Ab initio calculations of moment operators
Andrea Porro · Achim Schwenk · Alexander Tichai
We develop a framework that allows to calculate integrated properties of the nuclear response from first principles. Using the ab initio in-medium similarity renormalization group (IMSRG), we calculate the expectation values of moment operators that are linked to the multipole response of nuclei. This approach is applied to the isoscalar mono- and quadrupole as well as the isovector dipole response of closed-shell nuclei from $^{4}$ He to $^{78}$ Ni for different chiral two- and three-nucleon interactions. We find that the inclusion of many-body correlations in the nuclear ground state significantly impacts the multipole response when going from the random-phase approximation to the IMSRG level. Our IMSRG calculations lead to an improved description of experimental data in $^{16}$ O and $^{40}$ Ca, including a good reproduction of the Thomas-Reiche-Kuhn enhancement factor. These findings highlight the utility of the moment method as a benchmark for other ab initio approaches that describe nuclear response functions through the explicit treatment of excited states.
nucl-thPRC(2025)·6 citations
08
Meson-Exchange Currents in Quasielastic Charged-Current Neutrino Reactions with Single-Nucleon Knockout
P.R. Casale🇪🇸 · J.E. Amaro🇪🇸 · V. Belocchi🇮🇹 · M.B. Barbaro🇮🇹 · Marco Martini🇫🇷
The effect of meson-exchange currents on charged-current quasielastic neutrino scattering with single-nucleon emission is computed and analyzed within the relativistic Fermi gas model. This contribution arises primarily from the interference between one-body and two-body currents, where the two-body operator excites a 1p1h state in the presence of a second, spectator nucleon. The results obtained show a reduction of the vector, axial and vector-axial transverse response functions and, consequently, a decrease in the total neutrino cross section. In addition to a comparison with the non-relativistic limit, other models are also explored, such as the relativistic mean field model for nuclear matter and the superscaling analysis with relativistic effective mass, both of which yield qualitatively similar results.
↳ hep-phnucl-thPRC(2025)·5 citations
09
Analytic structure of stress-energy response functions and new Kubo formulae
Sangyong Jeon🇨🇦 · Alina Czajka🇵🇱 · Juhee Hong🇰🇷
Determining the transport properties of Quark-Gluon Plasma is one of the most important aspects of relativistic heavy ion collision studies. Field-theoretical calculations of the transport coefficients such as the shear and bulk viscosities require Kubo formulae which in turn require real-time correlation functions of stress-energy tensors. Consequently, knowing the analytic structure of these correlation functions is essential in any such studies. Using the energy-conservation laws and the results from the gravity-hydrodynamics analysis, we determine the low-frequency and low-wavenumber analytic structures of all stress-energy correlation functions in the rest frame of the medium. By comparing with the diffusion and sound spectra from the second-order and the third-order relativistic hydrodynamics, various new Kubo formulae are derived in the limit where the zero-frequency limit is taken first. We also show that the meaning of the Kubo formulae for relaxation times can change when higher-order terms are added to hydrodynamics. A subtle issue of taking the zero frequency and zero wavenumber limits when using skeleton diagrams is addressed as well.
↳ hep-phnucl-thPRC(2025)·5 citations
10
Low-energy atomic scattering: s-wave relation between the interaction potential and the phase shift
Francesco Lorenzi🇮🇹 · Luca Salasnich🇮🇹
We investigate the on-shell approximation in the context of s-wave scattering for ultracold two-body collisions. Our analysis systematically covers spatial dimensions D=1,2,3 , with the aim of identifying the regimes in which the approximation remains valid when applied to commonly used model interaction potentials. Specifically, we focus on the square well and delta shell potentials, both of which admit analytical solutions for the s-wave scattering problem in all dimensions considered. By employing the exact analytical expressions for the s-wave scattering phase shift, we perform a direct comparison between the exact on-shell matrix element of the interaction potential and their corresponding approximations across a range of collision momenta. Particular attention is given to the low-energy regime. Our findings indicate that, although the on-shell approximation generally improves with increasing momentum, its accuracy also improves for weaker potentials. Remarkably, in the limit of weak interactions, we demonstrate that the on-shell approximation becomes exact at leading order. In this regime, the approximation offers a controlled means of deriving the low-momentum expansion of the potential and may serve as a useful tool in constructing effective interactions for quantum field theories.
↳ cond-mat.quant-gasnucl-thAnnalen Phys.(2025)·0 citations
11
Understanding neutrino pion production with the GiBUU model
Qiyu Yan🇨🇳 · Kaile Wen🇨🇳 · Kai Gallmeister🇩🇪 · Xianguo Lu🇬🇧 · Ulrich Mosel🇩🇪 · Yangheng Zheng🇨🇳
Pion production is a major source of systematic uncertainty in neutrino oscillation measurements. We report a systematic investigation of neutrino-induced pion production using MINERvA and MicroBooNE data within the GiBUU theoretical framework. The analysis begins by establishing baseline model parameters using inclusive and pionless data from MINERvA, MicroBooNE, and T2K experiments. We then examine the role of in-medium effects, including resonance broadening and nucleon-nucleon final-state interactions. While agreement with individual datasets can be achieved through specific model configurations, we demonstrate the difficulty of a unified description across all experiments: MINERvA measurements prefer minimum in-medium modifications, whereas MicroBooNE data require the maximum in-medium enhancement, revealing the complexity and richness of the underlying nuclear dynamics.
↳ hep-exnucl-exnucl-thPRD(2025)·7 citations
12
Lattice study of scattering phase shifts for $D D^{*}$ and $B B^{*}$ systems using twisted boundary conditions: Search for bound state formation
Masato Nagatsuka🇯🇵 · Shoichi Sasaki🇯🇵
We investigate the $S$ - and $P$ -wave phase shifts for the $D D^{*}$ and $B B^{*}$ scatterings using Lüscher's finite-size method under twisted boundary conditions to search for doubly charmed tetraquaks, $T_{cc}^{+}$ , and doubly bottomed tetraquarks, $T_{bb}^{-}$ as the hadronic bound states. The $T_{cc}^{+}$ state was observed as a peak just bellow the $D D^{*}$ threshold by LHCb Collaboration, while the $T_{bb}^{-}$ state is a theoretically predicted tetraquark state having heavier quark flavors $bb u ˉ d ˉ$ . Lüscher's finite-size method is one of the well established methods for calculating the scattering phase shifts between two hadrons in lattice QCD simulations. Several studies have used simulations under the periodic boundary condition to determine the scattering phase shifts at a few discrete momenta for the $D D^{*}$ system. However, the scattering phase shift has not been investigated for the $B B^{*}$ system. In this study, $S$ - and $P$ -wave scattering phase shifts for the $D D^{*}$ and $B B^{*}$ systems in both $I = 0$ and $I = 1$ channels under several types of partially twisted boundary conditions. The use of the partially twisted boundary conditions enables us to obtain the scattering phase shift at any momentum by continuously varying the twisting angle. It also allows us to easily access the $P$ -wave scattering phase shifts through the mixing of $S$ - and $P$ -waves, which is induced by the imposed boundary conditions. The 2+1 flavor PACS-CS gauge ensembles at $m_{π} = 295$ , 411 and 569 MeV are used. For charm and bottom quarks, the relativistic heavy quark action is adopted to reduce the lattice discretization artifacts due to the heavy quark mass. We discuss the emergence of a shallow bound state with a binding energy of $O (100)$ keV at the physical pion mass in the $B B^{*}$ system, which has the quantum number $I (J^{P}) = 0 (1^{+})$ .
↳ hep-lathep-phnucl-thPRD(2025)·5 citations
13
Rotating Proto-Neutron Stars Admixed with Mirror Dark Matter: A two fluid approach
Adamu Issifu🇪🇸 · Andreas Konstantinou🇨🇾 · Prashant Thakur🇮🇳 · Tobias Frederico🇪🇸
This work investigates the impact of mirror dark matter (DM) on the global properties of rotating neutron stars (NSs) across evolutionary stages, from hot, lepton-rich protoneutron stars (PNSs) to cold, catalyzed NSs along the Kelvin-Helmholtz timescale. The baryonic matter (BM) is modeled using a relativistic mean-field (RMF) approach with density-dependent couplings, while the dark sector mirrors the visible sector with analogous thermodynamic conditions. Using a two-fluid formalism with purely gravitational DM-BM interaction, we find that rotation enlarges the star, whereas DM admixture increases compactness and enhances gravitational stability. However, increased compactness due to DM lowers the threshold for rotational instabilities, making DM-admixed stars more susceptible. Rotation decreases {central temperature behavior} by redistributing thermal energy over a larger volume and reducing central density, while DM raises temperatures by deepening the gravitational potential and increasing thermal energy. Stars become more prone to collapse and rotational instabilities as frequency ( $ν$ ) rises and the polar-to-equatorial radius ratio ( $r_{p} / r_{e}$ ) decreases, especially near the Keplerian limit ( $ν_{K}$ ). DM-admixed stars also show higher surface gravitational redshifts due to their compactness. Our results qualitatively agree with universal relations primarily derived for rotating cold stars. These findings highlight competing effects of rotation and DM on NS thermal evolution, structure, and observables, potentially offering indirect probes of DM within NSs.
↳ astro-ph.HEnucl-thPRD(2025)·11 citations

Affiliations

first authorsco-authorsvia INSPIRE