PaperPanorama

Nuclear Experiment·nucl-ex

Mon·Jul 13, 2026

7 papers—1 primary·6 cross-listed

All7Primary1Cross-lists6
  1. 01

    Beyond Sphericity in a Semi-Magic Nucleus: Multiple-Shape Coexistence in Sn

    Marco Siciliano🇮🇹 · Marco Rocchini🇮🇹 · Tomás R. Rodríguez🇪🇸 · Alain Goasduff🇮🇹 · Andres Illana🇮🇹 · Mansi Saxena🇺🇸 · Giacomo de Angelis🇮🇹 · Samuel Bakes🇮🇹 · Tuncay Bayram🇮🇹 · Dino Bazzacco🇮🇹 · Kevin Belvedere🇬🇧 · Giovanna Benzoni🇮🇹 and 34 other authors

    The study of nuclear shape evolution and coexistence provides key insight into the nuclear interaction, particularly in semi-magic systems expected to be spherical. A high-precision Coulomb-excitation measurement of Sn yields a comprehensive set of electromagnetic matrix elements, enabling the determination of quadrupole moments of the states and intrinsic deformations of the states. The results provide an unambiguous and direct proof of the rare phenomenon of multiple-shape coexistence, revealing a weakly deformed ground state incompatible with the spherical shape.

    nucl-exnucl-th0 citations
  2. 02

    Stochastic Similarity Renormalization Group

    Rongzhe Hu🇨🇳 · Xin Zhen🇨🇳 · Furong Xu🇨🇳 · Junchen Pei🇨🇳

    By integrating the quantum Monte Carlo technique into the similarity renormalization group (SRG), we have developed a stochastic SRG framework (SRGQMC) capable of both free-space two-body and in-medium many-body evolutions. This approach circumvents the combinatorial tensor-space explosion of many-body flow equations by mapping continuous unitary transformations onto an ensemble of signed random walkers. We benchmark the SRGQMC against deterministic free-space SRG evolutions of realistic nucleon-nucleon (NN) interactions, as well as against in-medium SRG (IMSRG) many-body calculations with the Richardson pairing model at two- and three-body levels [IMSRG(2)/(3)]. While a deterministic extension to the four-body level [IMSRG(4)] remains unfeasible due to prohibitive computational costs, we have achieved the first IMSRG(4) calculation by using the stochastic technique, demonstrating a substantial improvement toward the full configuration-interaction limit. This stochastic framework provides a practical pathway to higher-order IMSRG calculations.

    ↳ nucl-thcond-mat.str-elnucl-ex1 citation
  3. 03

    The impact of nuclear uncertainties on the p-process nucleosynthesis in Supernovae

    S. Martinet🇧🇪 · S. Goriely🇧🇪 · A. Choplin🇧🇪

    The p-process is responsible for the production of the stable neutron-deficient nuclei heavier than iron observed in the solar system. However, important nuclear uncertainties still limit our understanding of this nucleosynthesis process. Among the most significant are the nuclear level densities (NLDs) and photon strength functions (PSFs) entering the calculation of photodisintegration rates under supernova conditions. We investigate both model (systematic) and parameter (statistical) uncertainties affecting NLDs and PSFs and quantify their impact on p-process nucleosynthesis in type-Ia and type-II supernovae. Correlated model uncertainties are estimated using several NLD and PSF models that reproduce available experimental observables. Uncorrelated parameter uncertainties are evaluated with a backward-forward Monte Carlo approach, in which parameter variations are constrained by measured reaction rates before being propagated to unknown cross sections of neutron-deficient nuclei. The resulting uncertainties are propagated through p-process calculations while preserving model correlations. To identify the reactions driving abundance uncertainties, we combine regularized linear-response modeling, stability analysis, and contribution and interaction decompositions. We find that photoneutron-emission uncertainties dominate the overall uncertainty budget. The leading source of uncertainty arises from local parameter variations still compatible with current experimental constraints, highlighting the lack of constraining nuclear data in the neutron-deficient region. For many p-nuclei, the dominant contribution originates either from the photoneutron emission of the p-nucleus itself or from a nearby reaction along the same isotopic chain. While improved nuclear models remain important, many key reactions involve stable or near-stable nuclei and should be experimentally accessible.

    ↳ nucl-thastro-ph.SRnucl-ex0 citations
  4. 04

    Energy, time, and position resolution measurements of an array of large tapered LYSO crystals

    O. Beesley🇺🇸 · J. Carlton🇺🇸 · D. Ding🇨🇳 · S. Foster🇺🇸 · K. Frahm · T. Frank · L. Gibbons🇺🇸 · D. Goeldi🇨🇭 · T. Gorringe🇺🇸 · D. W. Hertzog🇺🇸 · S. Hochrein · J. Hui🇨🇳 and 10 other authors

    We report on the performance of six custom-made tapered LYSO crystals of unprecedented volume, which constitute a sector of the 19 radiation length electromagnetic calorimeter planned for the PIONEER experiment. The longitudinal response uniformity of each crystal was measured using radioactive sources before characterizing the energy and time resolution of the crystals in an array using a 20 to 80 MeV positron beam at the Paul Scherrer Institute. The array demonstrated an energy resolution better than 2 % for energies above 40 MeV and a time resolution better than 130 ps for energies above 30 MeV. The spatial resolution was measured in the central region of the array to be 4.9 mm at 70 MeV, and was extrapolated to 5.4 mm across a 30 mm radius region using Geant4 simulation. The measured properties satisfy the key design parameters of the PIONEER calorimeter for the measurement of rare pion decays.

    ↳ physics.ins-dethep-exnucl-ex0 citations
  5. 05

    Tensor-polarized parton distribution functions of the deuteron by a convolution model

    S. Kumano🇨🇳 · Kenshi Kuroki🇨🇳

    Tensor-polarized parton distribution functions (PDFs) are calculated for the deuteron by using a convolution formalism, where the tensor-polarized PDFs are given by the corresponding nucleon's unpolarized PDFs convoluted with the tensor-polarized nucleon momentum distribution in the deuteron. These distributions are obtained at GeV in order to compare with the tensor-polarized PDFs which were determined by HERMES data. The obtained distributions are very different from the ones determined from the HERMES data, which indicates further studies are needed to clarify the difference, possibly by considering a new mechanism beyond the simple bound system of a proton and a neutron. The obtained PDFs and are converted to the PDFs of the Trento convention and , and they are used for estimating the twist-3 PDFs and by using a Wandzura-Wilczek-like relation. Because deep-inelastic-scattering experiments are under preparation for structure functions with a tensor-polarized deuteron target at the Thomas Jefferson National Accelerator Facility, and a Drell-Yan experiment will be possible at hadron accelerator facilities, such as the Fermi National Accelerator Laboratory, the obtained tensor-polarized PDFs will be tested experimentally.

    ↳ hep-phhep-exhep-latnucl-ex+10 citations
  6. 06

    Diffusion Monte Carlo study of deuteron-like fully light hexaquarks

    M.C. Gordillo🇪🇸 · J. Segovia🇪🇸

    We perform a Diffusion Monte Carlo study of fully light hexaquarks containing three quarks and three quarks within a constituent-quark model. Both compact and baryon--baryon-like arrangements were considered separately. All compact hexaquark configurations are found well above their corresponding baryon--baryon thresholds, suggesting that deeply bound compact six-quark states are not favored in the light-quark sector within this model. By contrast, several dibaryon-like configurations lie close, but above, to the , , and thresholds and show spatial structures compatible with molecular states. One configuration exhibits two well-defined nucleon-like subclusters separated by several femtometers, characteristic of deuteron-like spatial clustering, although its calculated energy remains slightly above the corresponding threshold.

    ↳ hep-phhep-exhep-latnucl-ex+10 citations
  7. 07

    Running coupling effects in the anti-collinear resummation in high energy evolution

    Alex Kovner🇺🇸 · Michael Lublinsky🇮🇱 · Maxim Nefedov🇮🇱 · Vladimir Skokov🇺🇸

    We study the effects of the running of the QCD coupling on the anti-collinear resummation in JIMWLK evolution in the linear (BFKL) regime. We determine the appropriate scale choice for the coupling entering the JIMWLK kernel, and derive the anti-collinearly resummed BFKL kernel, which includes running-coupling effects both in the resummation equation (i.e. DGLAP) and in the JIMWLK kernel proper. We find that the running of the coupling generally further slows down BFKL evolution, as expected. Surprisingly however the value of the generalized characteristic function at is unaffected by the running coupling owing to subtle cancellations. We develop an approximation that allows us to use the generalized characteristic function to study the BFKL Green's function. Within this approximation we find that the Pomeron intercept in the anti-collinear regime is significantly reduced by both, the resummation and the running of the coupling.

    ↳ hep-phhep-exhep-thnucl-ex+10 citations

Affiliations

first authorsco-authorsvia INSPIRE