Nuclear Experiment·nucl-ex

Wed·Aug 26, 2026Wednesday·August 26, 2026

6 papers—2 primary·4 cross-listed

01
Cluster emission and its impact on the r-process nucleosynthesis
Natalia Thomas🇧🇪 · Silvia Bara🇧🇪 · Thomas Elias Cocolios🇧🇪 · Stephane Goriely🇧🇪 · Boris Andel🇸🇰 · Andrei N. Andreyev🇬🇧 · Alberto Camaiani🇮🇹 · James G. Cubiss🇬🇧 · Hilde De Witte🇧🇪 · Zoe Favier🇨🇭 · Michael Heines🇧🇪 · Fedor Ivandikov🇧🇪 and 11 other authors
Cluster emission is an exotic decay mode between alpha-decay and fission, in which a parent nucleus emits a cluster of nucleons heavier than an alpha-particle, but lighter than what is usually considered a fission fragment. The properties of cluster emission were investigated by analyzing five high-energy events detected in a spectrum of a mass A = 230 beam produced at ISOLDE (CERN). Under the assumption that these events were caused by cluster emission, the most likely parent-cluster pair responsible for the five high-energy events, was found to be $^{230} R a$ emitting $^{22} O$ , with a branching ratio of $(4.3$ +\- $1.9) \times 1 0^{- 9}$ . Four analytical formulas were used to estimate the partial half-lives of cluster emission for a group of neutron-rich nuclei. The decay rate was calculated for a selection of cluster nuclei for each parent isotope. The rates of all decay channels of cluster emission per parent nucleus were then included in calculations of the r-process nucleosynthesis in a neutron star merger in order to study the possible impact of cluster emission on the r-process nuclear production. The resulting isotopic abundance distributions were compared to those calculated for a case in which cluster emission was not considered. It was found that the inclusion of cluster emission decay rates from the simple analytical formulas available nowadays does not influence the results of the r-process nucleosynthesis.
nucl-exastro-ph.HE0 citations
02
STAR Highlights II: Study of Small Systems and the Search for New, Exotic Physics
Jiangyong Jia🇺🇸
Twenty-five years of RHIC operation have produced a uniquely diverse dataset, which enables a broad physics program. This contribution highlights recent STAR results in four areas: exotic-state searches and ultra-peripheral collisions; the onset of quark--gluon plasma (QGP) signatures in small systems; radial flow and its fluctuations; and polarization and spin correlations.
nucl-exnucl-th0 citations
03
Bound and Resonant Spectra of Few-Lepton Coulomb Systems
Liang-Zhen Wen🇨🇳 · Yao Ma🇨🇳 · Zhi-He Shen · Shi-Lin Zhu🇨🇳
We present a unified calculation of bound and resonant states in purely leptonic Coulomb systems: $e^{-} e^{-} e^{+}$ ( $Ps^{-}$ ), $μ^{+} e^{-} e^{-}$ ( $Mu^{-}$ ), $μ^{+} μ^{+} e^{-}$ ( $Mu_{2}^{+}$ ), $e^{+} e^{+} e^{-} e^{-}$ ( $Ps_{2}$ ), and $μ^{+} μ^{+} e^{-} e^{-}$ ( $Mu_{2}$ ). Using an extended stochastic variational method combined with the complex scaling method, we resolve the natural-parity $S$ - and $P$ -wave spectra. Near their respective $n = 2$ thresholds, all three trilepton systems exhibit Gailitis--Damburg sequences generated by $2 S$ and $2 P$ Stark mixing and the resulting inverse-square attraction. Although microscopically distinct from the Efimov effect, this mechanism produces the same inverse-square asymptotics and geometric scaling. The $Ps^{-}$ and $Mu^{-}$ systems exhibit resonance sequences of comparable density, whereas the $Mu_{2}^{+}$ produces a much denser spectrum, with 20 resolved members in the $^{3} P^{o}$ channel. In $Mu_{2}^{+}$ , the deeper states follow molecular Born--Oppenheimer configurations, while the near-threshold spectrum is governed by the atomic $Mu (2) + μ^{+}$ structure. In $Ps_{2}$ , coupling between threshold-degenerate configurations is essential for a near-threshold bound state. In $Mu_{2}$ , the Born--Oppenheimer organization of the resonance spectrum is channel dependent.
↳ physics.atom-phhep-exhep-phnucl-ex0 citations
04
Ultracold Neutron Sources: An Essentially Enhanced Optimal Operation Temperature for Ortho-Deuterium-Based Superthermal Converters
Erik Walz · Christoph Morkel
There is a longstanding dogma in the physics of ultracold neutrons (UCN): The optimal temperature of ortho-deuterium based UCN-sources must not exceed $5 K$ . This value has been established by the pioneering work of Golub et al. decades ago, utilizing previously established cross sections for solid ortho-deuterium. But recently, an improved calculation of the crucial 1-phonon up-scattering cross section - using the so-called corrected Incoherent Approximation - leads to a new upper limit for the optimal operation temperature of ortho-deuterium based UCN sources. After a discussion of the relevant cross sections of the $\mathrm{D}_2$-molecule we conclude that the optimal temperature lies between $10 K$ and $12 K$ , a factor 2 higher than estimated earlier. This offers significantly relaxed cryogenic conditions for UCN experiments with solid ortho-deuterium and especially for the operation of ortho-deuterium based ultracold neutron sources.
↳ physics.ins-detcond-mat.mtrl-scinucl-ex0 citations
05
Demonstration of inkjet-printed targets for activation cross-section measurements: deuteron-induced reactions on strontium up to 24 MeV
Akihiro Nambu · Masayuki Aikawa · Yudai Shigekawa · Yousuke Kanayama · Tomohiro Tomitsuka · Sayantani Mitra🇮🇳 · Hiromitsu Haba
Excitation functions for the $^{na t}$ Sr( $d, x$ ) reactions producing $^{86 m, g}$ Y, $^{87 m, g}$ Y, and $^{88}$ Y were measured up to 24-MeV deuteron energy using the stacked-foil technique and gamma-ray spectrometry. The $^{na t}$ Sr targets were prepared using an inkjet printing method to ensure sufficient uniformity. To the best of our knowledge, this is the first experimental report of excitation functions measured using inkjet-printed targets, demonstrating the applicability of this technique to cross-section measurements. The measured cross sections were discussed in comparison with literature data and TENDL-2023 predictions. Our cross sections were generally consistent with those reported in the previous study, but were slightly higher in the threshold energy region. The TENDL-2023 library generally overestimates the experimental values. We report the experimental cross sections for the $^{na t}$ Sr( $d, x$ ) $^{86 m}$ Y reaction for the first time. These measured cross sections contribute to the refinement of nuclear reaction databases for practical applications.
↳ physics.ins-detnucl-ex0 citations
06
Resummed Power Corrections in Nuclear DVCS
John Terry🇺🇸
Generalized Parton Distributions (GPDs) encode the three-dimensional structure of hadrons, yet their modification in nuclear matter remains largely unconstrained. We report the first derivation of resummed QCD power corrections to deeply virtual Compton scattering on nuclei. Extending techniques from inclusive deep inelastic scattering, we identify the nuclear-enhanced higher-twist contributions generated by coherent final-state scattering of the struck quark in the medium and resum them to all orders. The corrections are enhanced by an effective nuclear size $A_{eff}^{1/3}$ and result in an exclusive analogue of dynamical nuclear shadowing. The shift is controlled by a parameter already fixed by inclusive nuclear data, so no new nonperturbative input enters. We present quantitative predictions for nuclear modifications of beam-spin observables at the Electron--Ion Collider.
↳ hep-phnucl-exnucl-th0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Cluster emission and its impact on the r-process nucleosynthesis

STAR Highlights II: Study of Small Systems and the Search for New, Exotic Physics

Bound and Resonant Spectra of Few-Lepton Coulomb Systems

Ultracold Neutron Sources: An Essentially Enhanced Optimal Operation Temperature for Ortho-Deuterium-Based Superthermal Converters

Demonstration of inkjet-printed targets for activation cross-section measurements: deuteron-induced reactions on strontium up to 24 MeV

Resummed Power Corrections in Nuclear DVCS

Affiliations