Thu·Jul 3, 2025Thursday·July 3, 2025

1. 01*

   Structure studies of 257Db through combined {\alpha}, {\gamma} and internal-conversion-electron spectroscopy

   P. Brionnet🇫🇷 · A. Lopez-Martens🇫🇷 · O. Dorvaux🇫🇷 · Z. Asfari🇫🇷 · M. L. Chelnokov🇷🇺 · V. I. Chepigin🇷🇺 · H. Faure🇫🇷 · B. Gall🇫🇷 · K. Hauschild🇫🇷 · A. V. Isaev🇷🇺 · I. N. Izosimov🇷🇺 · A. A. Kuznetsova🇷🇺 and 12 other authors

   This work reports on the study of the decay properties along the ${}^{257}$Db decay chain using the GABRIELA setup. The first observation of a high-K isomer in ${}^{257}$Db is presented. In addition, an unreported $\alpha$-decay branch in ${}^{249}$Md has been evidenced, allowing to constrain the differences in energy of the $\alpha$-decaying levels in ${}^{249}$Md, ${}^{253}$Lr and ${}^{257}$Db. Finally, the combination of the observed fine structure $\alpha$-decay from the high-spin state in ${}^{257}$Db with the first observation the internal decay in ${}^{253}$Lr requires a revision of level and decay scheme. In particular, a change of parity for the high-spin state from 9/2${}^{+}$ to 9/2${}^{-}$ in the ${}^{257}$Db is suggested, and the implications of such a change are also discussed.

   nucl-exPRC(2025)·2 citations
2. 02*

   Nuclear Physics Confronts Relativistic Collisions Of Isobars

   Giuliano Giacalone🇨🇭 · Jiangyong Jia🇺🇸 · Vittorio Somà🇫🇷 · You Zhou🇩🇰 · Anatoli Afanasjev🇺🇸 · Massimiliano Alvioli🇮🇹 · Benjamin Bally🇩🇪 · Federica Capellino🇩🇪 · Jean-Paul Ebran🇫🇷 · Hannah Elfner🇩🇪 · Fernando G. Gardim🇧🇷 · André V. Giannini🇧🇷 and 34 other authors

   High-energy collisions involving the $A=96$ isobars ${}^{96}$Zr and ${}^{96}$Ru have been performed in 2018 at Brookhaven National Laboratory's Relativistic Heavy Ion Collider (RHIC) as a means to search for the chiral magnetic effect in QCD. This would manifest itself as specific deviations from unity in the ratio of observables taken between ${}^{96}$Zr+${}^{96}$Zr and ${}^{96}$Ru+${}^{96}$Ru collisions. Measurements of such ratios (released at the end of 2021) indeed reveal deviations from unity, but these are primarily caused by the two collided isobars having different radial profiles and intrinsic deformations. To make progress in understanding RHIC data, nuclear physicists across the energy spectrum gathered in Heidelberg in 2022 as part of an EMMI Rapid Reaction Task Force (RRTF) to address the following question. Does the combined effort of low-energy nuclear structure physics and high-energy heavy-ion physics enable us to understand the observations made in isobar collisions at RHIC?

   nucl-exhep-exhep-phnucl-th27 citations
3. 03*

   Frequency reproducibility of solid-state Th-229 nuclear clocks

   Tian Ooi🇺🇸 · Jack F. Doyle🇺🇸 · Chuankun Zhang🇺🇸 · Jacob S. Higgins🇺🇸 · Jun Ye🇺🇸 · Kjeld Beeks🇦🇹 · Tomas Sikorsky · Thorsten Schumm🇦🇹

   Solid-state ${}^{229}$Th nuclear clocks are set to provide new opportunities for precision metrology and fundamental physics. Taking advantage of a nuclear transition's inherent low sensitivity to its environment, orders of magnitude more emitters can be hosted in a solid-state crystal compared to current optical lattice atomic clocks. Furthermore, solid-state systems needing only simple thermal control are key to the development of field-deployable compact clocks. In this work, we explore and characterize the frequency reproducibility of the ${}^{229}$Th:CaF${}_2$ nuclear clock transition, a key performance metric for all clocks. We measure the transition linewidth and center frequency as a function of the doping concentration, temperature, and time. We report the concentration-dependent inhomogeneous linewidth of the nuclear transition, limited by the intrinsic host crystal properties. We determine an optimal working temperature for the ${}^{229}$Th:CaF${}_2$ nuclear clock at 195(5) K where the first-order thermal sensitivity vanishes. This would enable in-situ temperature co-sensing using different quadrupole-split lines, reducing the temperature-induced systematic shift below the 10${}^{-18}$ fractional frequency uncertainty level. At 195 K, the reproducibility of the nuclear transition frequency is 280 Hz (fractionally $1.4\times 10^{-13}$) for two differently doped ${}^{229}$Th:CaF${}_2$ crystals over four months. These results form the foundation for understanding, controlling, and harnessing the coherent nuclear excitation of ${}^{229}$Th in solid-state hosts, and for their applications in constraining temporal variations of fundamental constants.

   ↳ physics.atom-phnucl-exphysics.opticsquant-phNature(2026)·19 citations
4. 04*

   Bremsstrahlung emission accompanying ternary fission of \isotope[252]{Cf}

   Sergei P. Maydanyuk (1, 2 and 3)🇨🇳 · Ju-Jun Xie (1, 4 and 5)🇨🇳 · Sergei O. Omelchenko (3) ((1) Southern Center for Nuclear-Science Theory (SCNT), Institute of Modern Physics, Chinese Academy of Sciences, Huizhou, China, (2) Wigner Research Centre for Physics, Budapest, Hungary, (3) Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kyiv, Ukraine, (4) Heavy Ion Science and Technology Key Laboratory, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China, (5) School of Nuclear Sciences and Technology, University of Chinese Academy of Sciences, Beijing, China)🇺🇦

   \textbf{Background} In ternary fission, bremsstrahlung photons are emitted but those have never been studied yet theoretically and experimentally. In other reactions, bremsstrahlung has been studied for a long time. \textbf{Purpose} To clarify which new information about ternary fission can be obtained from study of bremsstrahlung emission accompanying the ternary fission of \isotope[252]{Cf}. \textbf{Methods} A new quantum model of emission of bremsstrahlung photons accompanying ternary fission of heavy nuclei with $\alpha$-particle as light charged particle is developed. The model takes into account geometry and dynamics of ternary fission. \textbf{Results} We present the theoretical results on the bremsstrahlung emission in the ternary fission of the \isotope[252]{Cf} nucleus. High sensitivity of the bremsstrahlung spectra is established by the model concerning to the following aspects of the ternary fission, and the theoretical calcualtions are in agreement with the preliminary experimental data. It is found that: (a) Photons are emitted with highest intensity in case of perpendicular motion of the $\alpha$\,particle concerning to fission axis; (b) Relative motion between heavy fragments reinforces significantly bremsstrahlung, leaving of $\alpha$-particle concerning to system of heavy fragments is less important; (c) Relative motion between two heavy fragments is faster, bremsstrahlung is more intensive. \textbf{Conclusions} Theoretical study of bremsstrahlung in ternary fission of the \isotope[252]{Cf} nucleus shows high sensitivity of bremsstrahlung spectra on the geometry and dynamics of ternary fission process. It is expected that new information can be obtained by the model when new experimental measurements of bremsstrahlung in ternary fission of the \isotope[252]{Cf} nucleus are available.

   ↳ nucl-thhep-exnucl-exJ.Phys.A(2026)·0 citations
5. 05*

   Probing the tetrahedral $\alpha$ clusters in relativistic ${}^{16}$O + ${}^{16}$O collisions

   Jin-Yu Hu🇨🇳 · Hao-jie Xu🇨🇳 · Xiaobao Wang🇨🇳 · Shi Pu🇨🇳

   Relativistic ${}^{16}$O +${}^{16}$O collisions probe the Quark-Gluon Plasma formed in small systems, while their collective phenomena illuminate the structure of ${}^{16}$O. Recently, various configurations of ${}^{16}$O from \textit{ab initio} calculations were implemented in heavy-ion models, such as the hydrodynamic model and a multiphase transport model (AMPT) to study cluster effects in relativistic ${}^{16}$O +${}^{16}$O collisions. However, divergent predictions across configurations and models complicate interpretations. In this Letter, we isolate the impact of multi-nucleon correlations in relativistic ${}^{16}$O +${}^{16}$O collisions while fixing the one-body density distribution of ${}^{16}$O. Our results show that the normalized ratios $\mathrm{Norm}(v_2\{2\}/v_2\{4\})$ and $\mathrm{Norm}(v_2\{2\}/v_3\{2\})$ effectively probe the effects of one-body density (e.g., tetrahedral symmetry) and multi-nucleon correlations (e.g., $\alpha$ clusters). These observables provide critical constraints for refining heavy-ion models, essential for investigating cluster configurations in light nuclei through relativistic heavy-ion collisions.

   ↳ nucl-thnucl-ex7 citations
6. 06*

   Transmutation of ${}^{16}$O and ${}^{20}$Ne at the Large Hadron Collider

   Govert Nijs🇨🇭 · Wilke van der Schee🇨🇭

   In July 2025 the Large Hadron Collider (LHC) will collide ${}^{16}$O${}^{16}$O and ${}^{20}$Ne${}^{20}$Ne isotopes in a quest to understand the physics of ultrarelativistic light ion collisions. One particular feature is that there are many smaller isotopes with the exact same charge over mass ratio that potentially can be produced and contaminate the beam composition. Using the Trajectum framework together with the GEMINI code we provide an estimate of the production cross-section and its consequences. A potential benefit could be the interesting measurement of the multiplicity and mean transverse momentum of ${}^{16}$O${}^4$He collisions.

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

   The Roper Resonance $N^{\ast }(1440)$ in Nucleon-Nucleon Collisions and the Issue of Dibaryons

   Heinz Clement🇩🇪

   In many reactions leading to excitations of the nucleon the Roper resonance $N^{\ast }(1440)$ can be sensed only by complex partial-wave analyses. In nucleon-nucleon collisions the isoscalar single-pion production as well as specific two-pion production channels present the Roper excitation free of competing resonance processes at a mass of 1370 MeV and a width of 150 MeV. A detailed analysis points to the formation of $N^{\ast }(1440)N$ dibaryonic systems during the nucleon-nucleon collision process similar to what is known from the $\Delta (1232)N$ threshold.

   ↳ hep-exnucl-exnucl-thActa Phys.Polon.B(2026)·1 citation

* 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.