Tue·Dec 30, 2025Tuesday·December 30, 2025

1. 01*

   Quantification of Oxygen and Carbon in Calcium Targets for Reliable Ca$(p,p\alpha )$ Measurements

   Junki Tanaka🇯🇵 · Riku Matsumura🇯🇵 · Taichi Miyagawa (for the ONOKORO collaboration)🇯🇵

   Reliable extraction of Ca$(p,p\alpha )$ cross sections requires accurate correction for oxygen and carbon impurities in calcium targets. In this work, the relative amounts of these light elements in ${}^{40,42,44,48}$Ca targets are determined using 65-MeV proton elastic scattering, where the Ca/Mylar yield ratios provide a direct measure of the corresponding O and C atomic ratios. These experimentally determined ratios are then applied to the 392-MeV $(p,p\alpha )$ spectra to subtract the O and C contributions in a fully data-driven manner. The method does not rely on assumptions about absolute contamination levels or reaction-model calculations, and enables a consistent and reliable determination of Ca$(p,p\alpha )$ yields across the calcium isotopic chain.

   nucl-exEPJ Web Conf.(2026)·0 citations
2. 02*

   Beta-like tracks in a cloud chamber from nickel cathodes after electrolysis

   Shyam Sunder Lakesar · Raj Ganesh S. Pala · K P Rajeev

   Electrochemically induced nuclear activity in hydrogen and deuterium-absorbing metals has been reported intermittently, yet a direct observation of nuclear signatures remains challenging. We electrolyzed light water with nickel cathodes under half-wave rectified RMS potentials of 5 V and 20 V and subsequently analyzed them using a Peltier-cooled diffusion-type Wilson cloud chamber for particle emission. The reacted cathodes emitted beta-like particles forming condensation tracks of lengths of 0.6 to 16 mm and an average activity of 0.6 plus or minus 0.1 counts per minute for 5 V samples and 1.0 plus or minus 0.1 counts per minute for 20 V samples. No such emissions were detected from unreacted samples. These results provide empirical evidence that electrochemical reactions can generate radioactive isotopes in condensed matter.

   nucl-ex0 citations
3. 03*

   Three-Nucleon Dynamics in the dp breakup collisions at 190 MeV/nucleon using the WASA detector at COSY-Jülich

   P. Adlarson🇸🇪 · W. Augustyniak🇵🇱 · W. Bardan · M. Bashkanov🇬🇧 · F.S. Bergmann · M. Berłowski🇵🇱 · A. Bondar🇷🇺 · M. Büscher · H. Calén · I. Ciepał🇵🇱 · H. Clement🇩🇪 · E. Czerwiński🇵🇱 and 78 other authors

   The differential cross section for the ${}^1$H$(d,pp)n$ breakup reaction at deuteron beam energy of 380 MeV has been determined with high precision for 189 angular configurations of outgoing protons in the region of forward laboratory angles. The cross section data were compared to theoretical predictions based on the state-of-the-art nucleon-nucleon potentials, combined with a three-nucleon force, the Coulomb interaction or carried out in a relativistic approach. In the region of the lowest differential cross section, the discrepancy between the data and the theoretical predictions is observed, also in the case of relativistic calculations.

   nucl-ex0 citations
4. 04*

   Orbital angular momentum in the pion and kaon: rest-frame and light-front

   Y.-Y. Xiao🇨🇳 · Z.-N. Xu🇪🇸 · Z.-Q. Yao🇩🇪 · C. D. Roberts🇨🇳 · J. Rodríguez-Quintero🇪🇸

   Orbital angular momentum (OAM) is not a Poincaré invariant quantity; so, its value is observer dependent. Notwithstanding that, in quantum chromodynamics, a Poincaré-invariant theory, OAM is part of every hadron wave function. Using continuum Schwinger function methods, we elucidate both the subjective character of in-hadron OAM and expose some of its impacts on pion and kaon structure and observables. For instance, working with light-front projections of their Bethe-Salpeter wave functions, it is found that the pion is a roughly 50/50 mix of light-front OAM zero and one components and the kaon is a 60/40 system. The overall picture is that (near) Nambu-Goldstone modes are complex bound states, each with significant intrinsic OAM, independent of the observer's reference frame. This feature must be accounted for in the calculation of observables. Inductively, the same is true for all hadrons.

   ↳ hep-phhep-exhep-latnucl-ex+1PLB(2026)·5 citations
5. 05*

   Quark Coalescence: Formation of Mesons Including Excited States

   R. J. Fries🇺🇸 · P. Virupapuram · J. Purcell🇺🇸 · H. Anconetani · W. Lippincott🇺🇸 · S. Robicheaux · M. Kordell🇺🇸 · C. M. Ko🇺🇸

   We discuss the quantum mechanics of coalescence of quark-antiquark pairs into mesons using a non-relativistic quark model. We derive the coalescence probabilities assuming a harmonic oscillator potential and generic Gaussian wave packet shapes for the initial quarks and antiquarks. Our particular emphasis is on modeling excited states of the meson spectrum consistently. We provide the formalism to systematically include excited states from the Particle Data Book, and many more predicted by the quark model, up to $L=4$ and masses of about 2.2 GeV for light flavors. We provide estimates of masses and decay branching ratios for unconfirmed states. We use a phase space picture which is appropriate for the quasi-classical nature of the information typically available for the quarks and antiquarks in applications like Monte Carlo simulations. We demonstrate that for typical parton configurations expected in jets, excited meson states are populated abundantly.

   ↳ hep-phnucl-exnucl-th1 citation
6. 06*

   Kinematic and dynamical origins of mean-$p_T$ fluctuations in heavy-ion collisions

   Lipei Du🇺🇸

   Event-by-event fluctuations of the mean transverse momentum (mean-$p_T$) provide a sensitive probe of collective dynamics beyond single-particle spectra and anisotropic flow. We present a systematic study of mean-$p_T$ fluctuation observables using a Bayesian-calibrated multistage hydrodynamic framework, including quantitative comparisons to RHIC measurements and model-based investigations of beam-energy and kinematic-acceptance effects. The experimental definitions employed by the STAR and ALICE Collaborations are implemented explicitly and found to yield consistent results within controlled limits. We study the centrality and beam-energy dependence of the observable, its sensitivity to key soft-sector ingredients, and the impact of the kinematic $p_T$ acceptance. By introducing scaled-$p_T$ cuts, we demonstrate that a part of the apparent energy dependence arises from kinematic projection effects, while the remaining trends reflect genuine collective dynamics. Our results establish mean-$p_T$ fluctuations as a nontrivial and independent validation of calibrated hydrodynamic descriptions of the quark--gluon plasma.

   ↳ nucl-thnucl-exPLB(2026)·3 citations
7. 07*

   SwinCCIR: An end-to-end deep network for Compton camera imaging reconstruction

   Minghao Dong🇨🇳 · Xinyang Luo🇺🇸 · Xujian Ouyang🇨🇳 · Yongshun Xiao

   Compton cameras (CCs) are a kind of gamma cameras which are designed to determine the directions of incident gammas based on the Compton scatter. However, the reconstruction of CCs face problems of severe artifacts and deformation due to the fundamental reconstruction principle of back-projection of Compton cones. Besides, a part of systematic errors originated from the performance of devices are hard to remove through calibration, leading to deterioration of imaging quality. Iterative algorithms and deep-learning based methods have been widely used to improve reconstruction. But most of them are optimization based on the results of back-projection. Therefore, we proposed an end-to-end deep learning framework, SwinCCIR, for CC imaging. Through adopting swin-transformer blocks and a transposed convolution-based image generation module, we established the relationship between the list-mode events and the radioactive source distribution. SwinCCIR was trained and validated on both simulated and practical dataset. The experimental results indicate that SwinCCIR effectively overcomes problems of conventional CC imaging, which are expected to be implemented in practical applications.

   ↳ eess.IVcs.CVnucl-ex0 citations
8. 08*

   The effect of inversion of $p$ and $f$ orbits on halo formation in heavy sodium isotopes

   Jagjit Singh🇬🇧 · J. Casal🇮🇹 · L. Fortunato🇮🇹 · N. R. Walet

   The role of the inversion of the $p$ and $f$ shell-model orbits in the emergence of halo structures in the ground states of neutron-rich ${}^{34,37,39}$Na is investigated. Families of two- and three-body models are constructed with effective core-neutron interactions, with parameter choices based on a combination of the available experimental data and systematic trends, as well as the GPT $n$-$n$ interaction and a phenomenological three-body force. Our results indicate a possible one-neutron halo in ${}^{34}$Na, while ${}^{37,39}$Na exhibit features of Borromean halos. The halo formation is driven by the weakening of the shell gap and inversion of the $2p_{3/2}$ and $1f_{7/2}$ orbits expected to occur somewhere near these masses. We further show that the electric dipole response provides a clear and sensitive probe of halo structure in these isotopes.

   ↳ nucl-thnucl-ex2 citations
9. 09*

   Neutron Star Equation of State with Nucleon Short-Range Correlations: A Concise Review and Open Issues

   Bao-Jun Cai🇨🇳 · Bao-An Li🇺🇸 · Yu-Gang Ma🇨🇳

   Nucleon short-range correlations (SRCs) and the associated high-momentum tail (HMT) in its momentum distribution $n(k)$ represent a universal feature of strongly interacting Fermi systems. In nuclear matter, SRCs arise primarily from the spin-isospin dependence of the tensor and short-range components of the nucleon-nucleon interaction, leading to a substantial depletion of its Fermi sea and a characteristic $k^{-4}$ tail populated predominantly by isosinglet neutron-proton pairs. These microscopic structures modify both the kinetic and interaction contributions to the Equation of State (EOS) of dense matter and thereby influence a broad range of neutron-star (NS) properties. This short review provides a streamlined overview of how SRC-induced changes in $n(k)$ reshape the kinetic EOS, including its symmetry energy part and how these effects propagate into macroscopic NS observables, including mass-radius relations, tidal deformabilities, direct Urca thresholds and core-crust transition. We summarize key existing results, highlight current observational constraints relevant for testing SRC-HMT effects, and outline open questions for future theoretical, experimental, and multimessenger studies of dense nucleonic matter.

   ↳ nucl-thastro-ph.HEhep-phhep-th+1Modern Physics Letters A, 2630005 (2026)·1 citation
10. 10*

    High-resolution 3D-printed plastic scintillators with tertiary dye

    Chandler Moore🇬🇧 · Michael Febbraro🇺🇸 · Juan Manfredi🇺🇸 · Allen Wood · Daniel Rutstrom · Thomas Ruland · Brennan Hackett🇺🇸 · Paul Hausladen

    Additive manufacturing offers efficient production of plastic scintillators with nontrivial geometries using vat polymerization, allowing fabrication of geometries which would be difficult or even impossible to produce using conventional subtractive manufacturing. This work presents a novel photocurable scintillator formula that includes coumarin 450 as a tertiary dye to enable high-resolution 3D printing via the manipulation of the 405 nm cure light. Bulk photocured and 3D printed (with and without tertiary dye) samples were compared through observational assessment and spectral response. All samples showed pulse shape discrimination between neutron and gamma events. Inclusion of the tertiary dye has minimal impact on emission spectrum and light output, but significant impact on print resolution as shown by comparison of printed high-complexity geometries and feature resolution test objects. With the use of a cure-limiting dye, unsupported features, such as freestanding pillars, were resolvable down to 0.7 mm. Even finer resolution at or below 0.1 mm was achieved in fully supported, integrated structures printed with off-the-shelf 405 nm desktop 3D printer. Scintillators demonstrated a light output up to 50% of EJ-200 with a PSD figure of merit up to 1.35 at 0.9-1.1 MeVee.

    ↳ physics.ins-detnucl-exphysics.app-phJINST(2025)·1 citation
11. 11*

    The Effect of Hadronic Matter on Parton Energy Loss

    Ritoban Datta🇺🇸 · Abhijit Majumder🇺🇸

    Modified thermal distributions (dispersion relations) are introduced within both the MATTER and LBT event generators used to describe jet modification in a heavy-ion collision, within the JETSCAPE framework. Hard partons, propagating through dense matter, scatter off the partonic substructure of the medium, leading to stimulated emission, accompanied by recoiling medium partons. We introduce a simple modification, a multiplicative $(1+a/T)$ correction to the dispersion relation of quarks and gluons (equivalent to an effective fugacity). This leads to calculated transport coefficients (e.g. $\hat{q}/T^3$) showing the expected behavior of depreciating at lower temperatures, including within the hot hadronic gas. This simple modification recovers the light-like dispersion relations at high temperatures, and introduces an excess depreciation factor for parton populations at lower temperatures, allowing partonic energy loss and recoil calculations to be extended into the hadronic phase. This modified distribution, in combination with initial state cold nuclear matter effects (shadowing), is used to simultaneously describe the nuclear modification factor and elliptic anisotropy of jets and leading hadrons, over multiple centralities and collision energies.

    ↳ hep-phhep-exnucl-exnucl-th2 citations
12. 12*

    Ion Optics for quasi-free $(p,p\alpha )$ reactions with Grand Raiden Spectrometer

    Taichi Miyagawa🇯🇵 · Junki Tanaka (for the ONOKORO collaboration)🇯🇵

    The quasi-free $(p,p\alpha )$ reaction is a powerful tool to probe preformed $\alpha$ clusters in nuclei, but it requires accurate reconstruction of both momentum and scattering angles at the reaction point. In this work, ion-optical analysis for $(p,p\alpha )$ measurements with the Grand Raiden spectrometer is presented. An under-focus optical setting was adopted to preserve sensitivity to the vertical scattering angle while maintaining high momentum resolution. The focal-plane geometry was determined independently as a purely geometrical reference. Momentum calibration was performed using elastic scattering of ${}^{206}$Pb$(p,p)$ at a fixed spectrometer angle. Scattering angles were reconstructed using ion-optical relations, and residual higher-order effects were corrected by a multidimensional fit. The dominant contributions to the reconstruction were found to arise from terms up to third order within the experimental acceptance. This ion-optical framework enables consistent event-by-event reconstruction of the reaction kinematics and provides a reliable basis for quasi-free $(p,p\alpha )$ analyses.

    ↳ physics.ins-detnucl-exEPJ Web Conf.(2026)·0 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.