Mon·Oct 6, 2025Monday·October 6, 2025

1. 01*

   The beta decay of Tz=-2 64Se and its descendants: the T=2 isobaric multiplet

   P. Aguilera🇪🇸 · F. Molina🇨🇱 · B. Rubio🇪🇸 · S.E.A. Orrigo🇪🇸 · W. Gelletly🇪🇸 · Y. Fujita🇯🇵 · J. Agramunt🇪🇸 · A. Algora🇪🇸 · V. Guadilla🇪🇸 · A. Montaner-Pizá🇪🇸 · A.I. Morales🇪🇸 · H.F. Arellano🇨🇱 and 40 other authors

   In this paper we present our results on the decay of 64Se. It is the heaviest Tz=-2 nucleus that both beta decays and has a stable mirror partner Tz=+2, thus allowing comparison with charge exchange reaction studies. The beta decays of 64Se and its descendants were studied at the RIKEN Nishina Center (Tokyo, Japan) following their production in the fragmentation of 78Kr on a beryllium target. Beta-delayed gamma-ray and particle radiation was identified for each of the nuclei in the decay chain allowing us to obtain decay schemes for 64Se, 64As, and 63Ge. Thus new excited states could be found for the descendant nuclei, including the interesting case of the N=Z nucleus 64Ge. Furthermore we observed for the first time the beta-delayed proton emission of 64Se and 64As. Based on these results we obtained proton branching ratios of 48.0(9)% in 64Se decay and 4.4(1)% in 64As decay. We obtained a half-life value of 22.5(6) ms for 64Se decay and half-lives slightly more precise than those in the literature for each nucleus involved in the decay chain. Using our results on the excited levels of 64As and the mass excess in the literature for 63Ge we obtained -39588(50) keV for the mass excess of 64As. Then based on the IMME we obtained the mass excess of -27429(88) keV for 64Se by extrapolation. The mirror process of 64Se beta decay, the charge exchange reaction 64Zn(3He,t)64Ga, has already been measured allowing us to study the mirror symmetry through the comparison of the weak force (beta decay) and strong force (charge exchange reaction). An interpretation of the decay schemes based on the idea of the Anti Analogue State is proposed.

   nucl-exPRC(2025)·1 citation
2. 02*

   Observation of long-range collective flow in OO and NeNe collisions and implications for nuclear structure studies

   CMS Collaboration

   The long-range collective flow of particles produced in oxygen-oxygen (OO) and neon-neon (NeNe) collisions is measured with the CMS detector at the CERN LHC. The data samples were collected at a center-of-mass energy per nucleon pair of 5.36 TeV, with integrated luminosities of 7 nb${}^{-1}$ and 0.8 nb${}^{-1}$ for OO and NeNe collisions, respectively. Two- and four-particle azimuthal correlations are measured over nearly five units of pseudorapidity. Significant elliptic ($v_2$) and triangular ($v_3$) flow harmonics are observed in both systems. The ratios of $v_n$ coefficients between NeNe and OO collisions suggest sensitivity to the intrinsic nuclear structure of the respective Ne and O ions. Hydrodynamic models with $\text{ab initio}$ nuclear structure inputs qualitatively reproduce the collision-overlap dependence of both the $v_n$ values and the NeNe to OO ratios. These measurements provide new constraints when modeling the interplay of nuclear structure and collective dynamics in collisions of ${}^{16}$O and ${}^{20}$Ne, respectively.

   nucl-exhep-exPRL(2026)·58 citations
3. 03*

   Imaging shapes of ground-state uranium-238 nuclei in high-energy nuclear collisions at RHIC

   Chunjian Zhang (for the STAR Collaboration)🇨🇳

   The shape and orientation of colliding nuclei play a crucial role in determining the initial conditions of the quark-gluon plasma (QGP), which influence key observables such as anisotropic and radial flow. In these proceedings, we present the measurements of $v_2$, $p_{\mathrm{T}}$ fluctuations and $v_2-p_{\mathrm{T}}$ correlations in ${}^{238}$U + ${}^{238}$U and ${}^{197}$Au + ${}^{197}$Au collisions at center of mass energies $\sqrt{s_{\mathrm{NN}}}=$ 193 and 200 GeV, respectively. Our results reveal significant differences in these observables between the two systems, particularly in the most central collisions. Comparisons with hydrodynamic model calculations indicate a large deformation in the ground states of ${}^{238}$U nuclei, consistent with previous low-energy experiments. However, data also imply a small deviation from axial symmetry of ${}^{238}$U [1]. Our work introduces a novel approach for imaging nuclear shapes, enhances the modeling of QGP initial conditions, and sheds light on nuclear structure evolution across different energy scales. The potential applications of this method for other nuclear species are discussed.

   nucl-exhep-exEPJ Web Conf.(2026)·0 citations
4. 04*

   Role of universal function of the nuclear proximity potential: A systematic study on the alpha-decay of heavy/super-heavy nuclei and {\alpha}-induced reactions

   S. Mohammadi · R. Gharaei · S. A. Alavi🇮🇷

   The idea of the universal function is fundamental advantage of proximity potential model. We present a systematic study of the role of universal function of the proximity potential model on alpha decay process for 250 ground state to ground state transitions using WKB approximation. In order to realize this goal, five universal functions proposed in the proximity models gp 77, Guo 2013, Ngo 80, Zhang 2013 and Prox. 2010 have been incorporated into the formalism of Prox. 77. The obtained results show that the radial behavior of universal function affects the penetration probability of the {\alpha} particle. The theoretical {\alpha} decay half lives are calculated and compared with the corresponding experimental data. It is shown that the Prox. 77 with Guo 2013 universal function provides the best fit to the available data. The role of the different universal functions in the {\alpha} decay half lives of super heavy nuclei (SHN) with Z from 104 to 118 are also studied. It is shown that the experimental half lives in the super heavy mass region are described well using the Prox. 77 with Zhang 2013 universal function. In this paper, the validity of the original and modified forms of the proximity 77 potential is also examined for complete fusion reactions between {\alpha} particle and 10 different target nuclei. Our results show that the measured {\alpha} induced fusion reaction cross sections can be well reproduced using the Prox. 77 with Zhang 2013 universal function for the reactions involving light and medium nuclei. Whereas, the Prox. 77 with Guo 2013 universal function model demonstrates a reliable agreement with the experimental data at sub-barrier energies for heavier systems.

   ↳ nucl-thhep-phnucl-exPRC(2025)·1 citation
5. 05*

   Principal Components of Nuclear Mass Model Residuals

   Y. Y. Huang🇨🇳 · X. H. Wu🇨🇳

   Principal Component Analysis (PCA) is applied to the residuals of six widely used nuclear mass models to uncover systematic deviations and identify missing physical effects in theoretical nuclear mass predictions. By analyzing the principal components of nuclear mass model residuals, this study reveals that no single dominant pattern governs the discrepancies across models. Instead, the residual structures are largely uncorrelated, indicating that current nuclear mass models fail to capture underlying nuclear residual effects in distinct and model-specific ways. These findings suggest that improvements to nuclear mass models should be guided by model-specific residual analyses rather than a one-size-fits-all approach.

   ↳ nucl-thnucl-exPLB(2026)·0 citations
6. 06*

   Statistical framework for nuclear parameter uncertainties in nucleosynthesis modeling of r- and i-process

   S. Martinet🇧🇪 · G. Goriely🇧🇪 · A. Choplin🇧🇪 · L. Siess

   Propagating nuclear uncertainties to nucleosynthesis simulations is key to understand the impact of theoretical uncertainties on the predictions, especially for processes far from the stability region, where nuclear properties are scarcely known. While systematic (model) uncertainties have been thoroughly studied, the statistical (parameter) ones have been more rarely explored, as constraining them is more challenging. We present here a methodology to determine coherently parameter uncertainties by anchoring the theoretical uncertainties to the experimentally known nuclear properties through the use of the Backward Forward Monte Carlo method. We use this methodology for two nucleosynthesis processes: the intermediate neutron capture process (i-process) and the rapid neutron capture process (r-process). We determine coherently for the i-process the uncertainties from the (n,$\gamma$) rates while we explore the impact of nuclear mass uncertainties for the r-process. The effect of parameter uncertainties on the final nucleosynthesis is in the same order as model uncertainties, suggesting the crucial need for more experimental constraints on key nuclei of interest. We show how key nuclear properties, such as relevant (n,$\gamma$) rates impacting the i-process tracers, could enhance tremendously the prediction of stellar evolution models by experimentally constraining them.

   ↳ astro-ph.SRnucl-exnucl-thEPJA(2025)·2 citations
7. 07*

   First Demonstration that Quark-Gluon Plasma has a Nonzero Resolution Length

   Arjun Srinivasan Kudinoor🇺🇸 · Daniel Pablos🇪🇸 · Krishna Rajagopal🇺🇸

   We report on our investigation in arXiv:2509.08881 of how recent jet substructure measurements constrain the resolution length $L_{\mathrm{res}}$ of the quark-gluon plasma formed in heavy-ion collisions. $L_{\mathrm{res}}$ is defined such that high-energy partons within a jet shower are resolved by the medium if and only if they are separated by a distance greater than $L_{\mathrm{res}}$. Using the Hybrid Model, we reproduce ALICE data on the scaled Soft Drop angle ${\theta }_g$ for $R=0.2$ charged-particle jets and ATLAS data on the Hard Group angle $\Delta R_{12}$ for $R=1$ jets reclustered from skinny $R=0.2$ inclusive subjets. We find that the narrowing of the ${\theta }_g$-distribution in PbPb collisions observed by ALICE and the suppression of $R=1$ jets with multiple skinny subjets in PbPb collisions observed by ATLAS rule out $L_{\mathrm{res}}=\infty$, where each entire parton shower loses energy to the plasma coherently as if it were a single colored object. We then compare Hybrid Model calculations to ATLAS measurements of $R_{\mathrm{AA}}$ of $R=1$ jets reclustered from $R=0.2$ subjets, as a function of the Soft Drop angle $d{R}_{12}$ obtained by grooming all charged-particle tracks associated with each $R=1$ jet. We demonstrate, for the first time, that the ATLAS data is inconsistent with $L_{\mathrm{res}}=0$, where the plasma resolves every splitting in a parton shower. Our results agree best with the data when QGP possesses a finite, nonzero $L_{\mathrm{res}}\sim (1-2)/(\pi T)$.

   ↳ hep-phnucl-exnucl-th0 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.