PaperPanorama

Nuclear Experiment·nucl-ex

Fri·Aug 7, 2026

7 papers—2 primary·5 cross-listed

All7Primary2Cross-lists5
  1. 01

    ePIC Early Science Report

    D. Abbott · N. Abdelrahman · S. Abhijit · I. Abualrob · R. B. Achari · J. Adam · L. Adamczyk · K. Adkins · A. Affolder · K. Agarwal · J. Agarwala · N. Agrawal and 787 other authors

    This Early Science Report from the ePIC Collaboration outlines the compelling physics program achievable during the first years of operation of the Electron-Ion Collider (EIC), prior to the establishment of the full design luminosity and energy range. The analyses are based on realistic early-running beam configurations and detailed Geant4 ePIC detector simulations, hit digitization and data reconstruction. The projected studies from the physics working groups of ePIC span inclusive, semi-inclusive, exclusive, diffractive and tagging, as well as jet and heavy flavor measurements in both electron-proton and electron-ion collisions. Even before the collider reaches its full design performance, these measurements will constrain parton distribution functions in nucleons and nuclei, access transverse-momentum-dependent and spin-dependent observables, probe gluon dynamics in nuclei, and initiate a program of imaging of quarks and gluons. Each measurement is directly connected to the core science pillars of the EIC, identified in the 2018 report by the National Academy of Sciences: understanding the origin of the nucleon mass, unraveling the spin structure of the nucleon, and exploring the emergent properties of dense gluonic matter. The results presented here provide examples that demonstrate that the early years of EIC running with ePIC will deliver novel world-leading insights into Quantum Chromodynamics. In addition, the early science program will establish measurement and analysis methodologies that will pave the way to the subsequent full EIC physics program.

    nucl-exhep-ex2 citations
  2. 02

    Three-baryon femtoscopy as an effective 33 scattering experiment

    ALICE Collaboration

    Scattering experiments have long been the gold standard for constraining hadronhadron interactions, providing direct information on the angular momentum and spin dependence over a wide range of kinematic configurations. However, experimental constraints on three-body dynamics remain limited, specifically for unbound systems and systems involving short-lived hadrons. In this work, the three-proton correlation function is measured in pp collisions at TeV with ALICE at the LHC and presented as a novel approach to access hadronic interactions in three-body systems. A new analysis strategy is employed to isolate the ppp contribution to the correlation function by correcting for background channels and experimental effects, and enabling a direct comparison with state-of-the-art three-body continuum calculations. The extracted correlation function provides the first direct access to the isospin three-body system. The measured observable is found to be sensitive to the partial-wave structure of the nucleonnucleon interaction and indicates that the nuclear interaction acts even at high angular momentum and parity states of the three-body system, revealing an effective long-range attractive component, observed experimentally for the first time in a three-proton continuum system. Hence, three-hadron femtoscopy emerges as an effective 33 scattering experiment with three unbound hadrons in initial and final states. The copious production of hyperons at the modern high-energy colliders ensures the possibility of extending such measurements beyond nucleons, opening a new avenue for future precision studies of three-body dynamics in the strangeness sector.

    nucl-exhep-exnucl-th0 citations
  3. 03

    Photon-nucleon entanglement in Compton scattering at low and high energies

    Yoshitaka Hatta🇺🇸 · Víctor Martínez-Fernández🇫🇷

    We study spin-spin entanglement in the final state photon-nucleon system in Compton scattering, both at low energy below the pion threshold and at high energy in perturbative QCD to next-to-leading order. We first establish a no-go theorem showing that, for any spin- target, entanglement cannot be generated in unpolarized Compton scattering if the scattering amplitudes are real. We then consider polarized Compton scattering off the electron, the proton and the neutron. At low energy, we uncover a rich variety of maximally entangled Bell states and their unitary equivalents realized across different regions of the kinematic plane. Interestingly, the proton and neutron targets exhibit distinct patterns of entanglement. In the neutron case, the electric and magnetic polarizabilities dramatically influence the pattern and even the existence of entanglement. This suggests that entanglement can serve as a novel tool for investigating the detailed electromagnetic properties of the nucleons.

    ↳ hep-phhep-exnucl-exnucl-th+12 citations
  4. 04

    TITAN mass measurements of neutron-rich Cs, Ba and r-process lanthanide abundances

    T.-H. Yeh · J.D. Cardona🇨🇦 · Y. Wang🇨🇳 · J. Ash🇨🇦 · B. Ashrafkhani🇨🇦 · I. Belosovic · J. Bergmann🇩🇪 · E. Dunling · L. Egoriti · G. Gelinas · G. Gwinner🇨🇦 · Z. Hockenbery🇨🇦 and 17 other authors

    We present measurements for the masses of five neutron-rich isotopes, Cs and Ba, probed for the first time by TITAN at TRIUMF with time-of-flight measurement techniques. We propagate these masses to the nuclear reaction and decay data required for the simulation of the rapid neutron capture process (r-process) nucleosynthesis in neutron star mergers. We show that these neutron-rich masses affect the abundance predictions near mass number corresponding to lanthanide element abundances at and . We demonstrate that these new TITAN masses smooth out the odd-even effect in isotopic abundance predictions near in both fission cycling astrophysical conditions and conditions that do not reach actinides. We further show that these new masses adjust how fission fragments settle into place when forming the final abundances, and consider the effect on comparisons with stellar abundance ratios such as [Ag/Eu], [Sm/Eu], and [Nd/Eu].

    ↳ nucl-thnucl-ex0 citations
  5. 05

    Millisecond-Scale Neural Operator Surrogates for Double-Null Free-Boundary Grad-Shafranov Equilibria

    Plamen G. Krastev

    The Grad-Shafranov (GS) equation governs ideal magnetohydrodynamic equilibrium in tokamak plasmas. Free-boundary GS solvers are central to diverted-equilibrium modeling, but nonlinear Picard iteration introduces computational cost and sample-dependent latency that can become prohibitive in optimization, modeling, and control-oriented loops. Here we train a geometrically conditioned Fourier Neural Operator (FNO) to learn a constrained forward map from spatial coordinates, scalar operating parameters , and prescribed X-point locations to the poloidal-flux field . The model is trained on a controlled family of constrained double-null free-boundary equilibria generated with \textsc{FreeGS} for a single fixed machine geometry and prescribed topology. The best model achieves a mean relative error of , with test error following an empirical power law over . It recovers both X-points to within cm and localizes the O-point to cm. As a physics-consistency diagnostic, the predicted fields satisfy an external finite-difference GS residual evaluation at the same level as the ground-truth fields, with mean normalized residual , indistinguishable from the \textsc{FreeGS} baseline using the same diagnostic. The trained FNO evaluates one equilibrium in ms on GPU and ms on CPU, corresponding to speedups of and relative to \textsc{FreeGS} as configured here, with near-deterministic latency (p95/median ). These results show that neural-operator surrogates can provide accurate, geometrically precise, millisecond-scale equilibrium evaluations for magnetic-confinement fusion workflows within a prescribed topology and machine geometry.

    ↳ physics.plasm-phnucl-exnucl-thphysics.comp-ph0 citations
  6. 06

    QCD Chiral Crossover Line from Lee-Yang Edge Singularities

    Heng-Tong Ding🇨🇳 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Kai-Fan Ye🇨🇳

    We propose a universality-based reconstruction of the QCD chiral crossover line from Lee-Yang edge singularities in the complex baryon chemical potential plane. The framework maps lattice-extracted complex Lee-Yang-zero estimates, treated as proxies for edge singularities, to the universal chiral Lee-Yang edge and thereby determines the dependence of both the chiral critical line in the light-quark chiral limit and the pseudo-critical crossover line at physical quark masses. As an illustration, we apply the framework to Lee-Yang-zero estimates recently obtained by the Wuppertal-Budapest collaboration from high-statistics lattice QCD simulations. Without imposing the previously determined small- expansion of the crossover line as input, the reconstructed curvature is consistent with existing continuum lattice-QCD results at small . The fitted chiral-limit transition temperature is also compatible with existing chiral-scaling analyses. These results demonstrate that lattice information on Lee-Yang singularities, combined with universal chiral scaling, provides a quantitatively consistent constraint on the QCD crossover line within the present temperature window and establishes a framework that can be systematically improved with future Lee-Yang-zero determinations.

    ↳ hep-lathep-phnucl-exnucl-th0 citations
  7. 07

    A platform for nuclear symmetry-violation searches with laser-coolable molecules carrying spinful nuclei

    Tatsam Garg · Jakob Weiß · Tesse Tiemens · Charly Beulenkamp · Andreas Schindewolf · Tim Langen

    Cold heavy molecules are promising systems for exploring nuclear - and -violating phenomena in search of new physics beyond the Standard Model. However, most proposed experimental strategies and their early realizations to date have been limited to proof-of-principle molecular species with effectively spin-zero nuclei that are not sensitive to nuclear symmetry-violating phenomena. Here, we introduce a comprehensive experimental toolbox that integrates cooling, trapping, coherent state manipulation, and a complete precision-measurement protocol that is applicable to molecules carrying relevant nuclear spins. Using BaF and nuclear-spin-dependent parity violation (NSD-PV) as representative species and benchmark application, respectively, our approach achieves a projected statistical sensitivity roughly two orders of magnitude beyond comparable molecular beams by combining techniques already demonstrated individually in current experiments. This level of precision could provide realistic experimental access not only to the enhanced NSD-PV signals arising from the heavy Ba nucleus within this molecule but also to the contributions from the lighter F nucleus, bringing direct benchmarks of nuclear \textit{ab initio} theory within reach. We further identify a candidate magic wavelength as a route to second-scale rotational coherence in future experiments. The techniques developed here can be transferred to measurements of nuclear Schiff and magnetic quadrupole moments in molecules containing deformed nuclei, establishing a general platform for laboratory searches for nuclear symmetry violations.

    ↳ physics.atom-phnucl-exquant-ph0 citations

Affiliations

first authorsco-authorsvia INSPIRE