Nuclear Theory·nucl-th

Wednesday·April 16, 2025

11 papers—2 primary·9 cross-listed

03
Exploring the effects of $α$ -clustered structure of $^{16} O$ nuclei in anisotropic flow fluctuations in $^{16} O$ - $^{16} O$ collisions at the LHC within a CGC+Hydro framework
Suraj Prasad🇮🇳 · Neelkamal Mallick🇮🇳 · Raghunath Sahoo🇮🇳 · Gergely Gabor Barnafoldi🇭🇺
In this paper, we explore the effects of the presence of clustered nuclear structure of $^{16} O$ in the final state elliptic flow fluctuations through $^{16} O$ - $^{16} O$ collisions at $s_{NN} = 7$ TeV within a hybrid model, IPGlasma+MUSIC+iSS+ UrQMD. We compare the results of elliptic flow fluctuations using $α$ -clustered nuclear structure to the Woods-Saxon nuclear profile having no clustered structure. We observe a significant difference in the elliptic flow fluctuations, which arise due to the consideration of a clustered nuclear structure of $^{16} O$ .
↳ hep-phhep-exnucl-exnucl-thJ.Subatomic Part.Cosmol.(2026)·0 citations
04
Beyond Poincaré Stresses: A Modern Quantum Field Theory Take on Hydrogen's Electromagnetic Mass
Qasem Exirifard🇨🇦 · Alessio D'Errico🇨🇦 · Ebrahim Karimi🇨🇦
We revisit the longstanding electromagnetic mass problem from a modern quantum field theory perspective. Focusing on a system of two widely separated hydrogen atoms, one in an excited $n S$ state and the other in the ground $1 S$ state, we isolate the electromagnetic contribution to the electron's total linear momentum by comparing the full energy-momentum tensor with the predictions of a point-like bound state model. Our analysis reveals that the leading perturbative correction introduces a factor $4/3$ , which, along with subsequent corrections, indicates that the effective electromagnetic mass deviates from the conventional relation $E / c^{2}$ . This discrepancy is attributed to the intrinsic nonlocality of the electromagnetic field, rather than to additional compensating mechanisms such as Poincaré stresses. We further contrast our quantum field theory results with the highly accurate predictions of the Schrödinger equation, which, despite neglecting higher-order terms, achieves an average error on the order of $1 0^{- 5} %$ . Attempts to improve this accuracy via perturbative inclusion of the self-interaction of the electron's wave function instead increase the error, prompting a re-examination of the underlying perturbative assumptions. Our findings suggest that a non-perturbative treatment of the tree-level action may be required to fully capture the dynamics of bound states in quantum field theory.
↳ hep-phhep-thnucl-thquant-ph0 citations
05
Sakai-Sugimoto Model in an Off-Shell: Chiral Lagrangian to All Orders
Michael Lublinsky🇮🇱 · Timofey Solomko🇮🇱
The Sakai-Sugimoto holographic model is famous for implementing the approximate chiral symmetry of QCD and reproducing the Chiral Lagrangian in a top-down approach. In this manuscript, we revisit the model in a formalism that is somewhat different from the original work by Sakai and Sugimoto: We start by identifying boundary degrees of freedom and splitting the bulk equations of motion into dynamical ones and constraints. The former are then solved to all orders in derivatives of the boundary fields. The constraints are left unsolved, leaving the dynamical degrees of freedom off-shell. This approach enables us to systematically derive the effective action of the boundary theory. The derived effective action is very rich in physics: it contains an $U (N_{f})$ multiplet of massless pseudoscalars interacting (via trilinear and higher terms) with towers of massive (axial-)vector mesons. In contrast to the previous studies, our effective action is non-local. The original Chiral Lagrangian is recovered as its local expansion in small $π$ -meson momenta (derivative expansion). We particularly zoom in on the values of four derivative terms couplings, the low energy constants, and compare those with the ones reported in the literature.
↳ hep-thhep-phnucl-thJHEP(2025)·0 citations
06
Hadronic light-by-light scattering in the anomalous magnetic moments of electron and $τ$
Martin Hoferichter🇨🇭 · Peter Stoffer🇨🇭 · Maximilian Zillinger🇨🇭
In Refs. [1,2] we provided a complete dispersive evaluation of the hadronic light-by-light (HLbL) contribution to the anomalous magnetic moment of the muon. While the evaluation strategy was developed for the kinematic situation determined by the muon mass, a similar approach also applies to the HLbL corrections to the anomalous magnetic moments of the electron and $τ$ lepton, shifting the sensitivity in the loop integrals to smaller and larger momenta, respectively. In this Letter, we propagate the corresponding uncertainties of the various contributions, obtaining $a_{e}^{HLbL} = 3.51 (23) \times 1 0^{- 14}$ and $a_{τ}^{HLbL} = 3.77 (29) \times 1 0^{- 8}$ .
↳ hep-phhep-exhep-latnucl-thPLB(2025)·19 citations
07
Simulating lattice fermion doubling with a Floquet drive
Raúl A. Briceño🇺🇸 · William Gyory🇺🇸 · Thomas Iadecola🇺🇸 · Srimoyee Sen🇺🇸
We consider a recently discovered mathematical correspondence between the spectra of a naively discretized lattice fermion and that of a periodically driven (i.e., Floquet) quantum system and enhance it into an infrared equivalence between the two systems. The equivalence can be framed as a duality relation, allowing us to simulate a two-flavor discrete-time fermion theory on the lattice side, where the two flavors arise from time discretization, using a single-flavor fermion theory on the Floquet side. Our demonstration establishes an equivalence between (i) the fermion content, (ii) the correlation functions, and consequently (iii) observables of the two theories in the infrared, going substantially beyond the previously discovered spectral equivalence. We also show how interactions may be incorporated into this enhanced infrared equivalence.
↳ hep-latcond-mat.mes-hallhep-thnucl-th+1PRD(2025)·2 citations
08
Statistical complexity as a probe of mass and phase structure in compact objects
Ch.D. Giannios🇩🇪 · P.S. Koliogiannis🇩🇪 · Ch.C. Moustakidis🇩🇪
In this work, we present a comprehensive and systematic study of the statistical complexity, originally introduced by López-Ruiz, Mancini, and Calbet [Phys. Lett. A 209, 321-326 (1995)], across a broad range of compact star models. We explore how complexity correlates not only with macroscopic observables such as mass and radius, but also with the microscopic characteristics of the underlying equation of state. By incorporating both realistic equations of state and analytical solutions to Einstein's field equations, we demonstrate that gravitational mass plays a dominant role in determining the behavior of complexity. Furthermore, we show that strong phase transitions within the stellar interior, such as those hypothesized in hybrid stars, can manifest as distinct features in the complexity profile, offering a potential informational signature of such transitions. This work offers new insights into the link between information theory and compact object physics, highlighting complexity's potential as a diagnostic tool in astrophysics.
↳ astro-ph.SRastro-ph.HEgr-qcnucl-th+1PLA(2025)·0 citations
09
Origin of Reactor Antineutrino Anomaly
L.M. Slad🇷🇺
The reactor antineutrino anomaly, discovered in 2011, means a noticeable difference between the observed rate of inverse beta decays and the expected (theoretical) rate of such processes based on the measurement of the spectra of electrons in beta decay of $^{235}$ U, $^{239}$ Pu, $^{241}$ Pu, and $^{238}$ U nuclei and their subsequent conversion into right-handed antineutrino spectra. This paper provides a rationale for the fact that both right-handed and left-handed antineutrinos are produced in beta decays of nuclei. But the conversion procedure in any case assigns a right-handed antineutrino to each electron, which leads to the superiority of the theoretical rate of inverse beta decays over the experimental one. The right-handed antineutrino is produced in the mode of beta decay of the nucleus due to the standard electroweak interaction. The left-handed antineutrino appears in the mode caused by the existence of a interaction, the carrier of which is a massless pseudoscalar boson having a Yukawa coupling with the electron neutrino and nucleons. The emission of such a boson from a virtual right-handed antineutrino converts it into a free left-handed antineutrino.
↳ hep-phhep-exnucl-th0 citations
10
Role of Matter Inhomogeneity on Fast Flavor Conversion of Supernova Neutrinos
Soumya Bhattacharyya🇹🇼 · Meng-Ru Wu🇹🇼 · Zewei Xiong🇩🇪
We study how a spatially varying matter potential $λ$ , arising from neutrino-electron forward scattering, affects the onset, evolution, and nonlinear outcome of fast neutrino flavor conversions (FFCs) triggered by the presence of zero crossings in the angular distribution of the neutrino electron lepton number (ELN). We find that increasing the spatial variation rate of $λ$ can strongly influence FFC dynamics and even stabilize systems that are otherwise unstable. Using stability analysis based solely on initial conditions, we identify for the first time a critical variation rate above which no FFC occurs even if the flavor instability exists. Below this critical rate, a substantial $λ$ variation delays the onset of FFCs and quickly generates small-scale, incoherent features in the nonlinear regime, which leads to a similar coarse-grained outcome that eliminates the ELN crossing as in the homogeneous case. Our findings emphasize the need to consider matter inhomogeneity in improved supernova models accounting for FFCs, and we propose simple analytical ways to incorporate this effect.
↳ astro-ph.HEastro-ph.COastro-ph.SRhep-ph+113 citations
11
Combined Evidence for the $X_{17}$ Boson After PADME Results on Resonant Production in Positron Annihilation
Fernando Arias-Aragón🇮🇹 · Giovanni Grilli di Cortona🇮🇹 · Enrico Nardi🇮🇹 · Claudio Toni🇫🇷
The Positron Annihilation into Dark Matter Experiment at the Laboratori Nazionali di Frascati has reported an excess of $e^{+} e^{-}$ final-state events from positron annihilation on fixed-target atomic electrons. While the global significance remains at the $(1.77 \pm 0.15) σ$ level, the excess is centered around $s \sim 17 MeV$ , coinciding with the invariant mass at which anomalous $e^{+} e^{-}$ pair production has previously been observed in nuclear transitions from excited to ground states in $^{8}$ Be, $^{4}$ He and $^{12}$ C, thereby strengthening the case for a common underlying origin, possibly involving a hypothetical new $X_{17}$ boson. We discuss the significance of this independent accelerator-based evidence. Combining it with existing nuclear physics results, we obtain a value for the $X_{17}$ mass of $m_{X_{17}} = 16.88 \pm 0.05 MeV$ , reducing the uncertainty from nuclear physics determinations by more than a factor of two, and mitigating the impact of poorly known correlations among their systematic errors.
↳ hep-phhep-exnucl-exnucl-thEPJC(2026)·11 citations

Affiliations

first authorsco-authorsvia INSPIRE