Thu·Nov 6, 2025Thursday·November 6, 2025

1. 01*

   Large-Scale Calculations of $\beta$-Decay Rates and Implications for $r$-Process Nucleosynthesis

   A. Ravlić🇺🇸 · Y. Saito · W. Nazarewicz🇺🇸

   Nuclear $\beta$ decay is a key element of the astrophysical rapid neutron capture process ($r$-process). In this paper, we present state-of-the-art global $\beta$-decay calculations based on the quantified relativistic nuclear energy density functional theory and the deformed proton-neutron quasiparticle random-phase approximation. Our analysis considers contributions from allowed and first-forbidden transitions. We used two point-coupling functionals with carefully calibrated time-odd terms and isoscalar pairing strength. The new calculations display consistent results for both employed functionals, especially near the neutron drip line, suggesting slower $\beta$ decays past the $N=126$ neutron shell closure than in commonly used $\beta$-decay models. The new rates, along with the existing rates based on the latest non-relativistic calculations, are found to slow down the synthesis of heavy elements in the $r$-process and significantly reduce the contribution of neutron-induced fission.

   ↳ nucl-thastro-ph.HEnucl-exPRC(2026)·3 citations
2. 02*

   Constraining capture cross sections using proton inelastic scattering as a surrogate reaction

   Aaina Thapa🇺🇸 · Jutta Escher🇺🇸 · Emanuel Chimanski🇺🇸 · Oliver Gorton🇺🇸 · Marc Dupuis🇫🇷 · Eun Jin In🇺🇸 · Shuya Ota🇯🇵 · Sophie Péru🇫🇷 · Walid Younes🇺🇸

   The surrogate reaction method is an alternative to direct measurements of compound nuclear reaction cross sections. We introduce theory tools for extracting capture cross sections from experiments that use proton inelastic scattering as a surrogate reaction mechanism. This makes it possible to constrain compound nucleus decay models which are typically the largest source of uncertainty in capture cross section calculations. This letter describes the theory developments that were used to simultaneously infer ${}^{89}$Y$(p,\gamma )$ and ${}^{89}$Zr$(n,\gamma )$ cross sections from ${}^{90}$Zr$(p,p^{\prime }\gamma )$ surrogate measurements.

   ↳ nucl-thnucl-exPLB(2026)·2 citations
3. 03*

   {\alpha}/{\gamma} discrimination method for bulky BaF2 detector used in {\gamma} total absorption facility

   Chong Zou · Qiwei Zhang🇨🇳 · Guangyuan Luan🇨🇳 · Hongyi Wu🇺🇸 · Haotian Luo🇨🇳 · Xuanbo Chen🇨🇳 · Xiaoyu Wang · Guozhu He · Jie Ren🇨🇳 · Hanxiong Huang🇨🇳 · Xichao Ruan🇨🇳 · Jie Bao · Xinghua Zhu

   The gamma-ray total absorption facility (GTAF) composed of 40 BaF2 detection units is designed to measure the cross section data of neutron radiation capture reaction online, in order to comply with the experimental nuclear data sheet.We have found that one of the most important sources of experimental background is the initial alpha particles emitted by the BaF2 crystal. Developing data analysis algorithms to eliminate the influence of alpha particles in experimental data has become a key aspect. In this work, in order to meet the needs of data acquisition, online measurement and analysis of neutron radiation cross section, the GTAF data acquisition system adopts a full waveform acquisition method, which results in a large number of data recorded, transmitted, and stored during experiment, which also affects the uncertainty of the cross-section data.Based on the signal waveform characteristics of the BaF2 detection unit, in order to solve the aforementioned problems, three methods, namely the ratio of fast component to total component, pulse width, and time decay constant, are used to identify and distinguish alpha particles and gamma rays. The quality factor FOM is utilized as an evaluation value and several experiments are conducted using three radioactive sources (22Na, 137Cs, 60Co) for verification.

   ↳ physics.ins-detnucl-exActa Phys.Sin.(2025)·1 citation
4. 04*

   Design and development of optical modules for the BUTTON-30 detector

   D. S. Bhattacharya · J. Bae · M. Bergevin · J. Boissevain · S. Boyd · K. Bridges · L. Capponi · J. Coleman · D. Costanzo · T. Cunniffe · S. A. Dazeley · M. V. Diwan and 54 other authors

   BUTTON-30 is a neutrino detector demonstrator located in the STFC Boulby underground facility in the north-east of England. The main goal of the project is to deploy and test the performance of the gadolinium-loaded water-based liquid scintillator for neutrino detection in an underground environment. This will pave the way for a future large-volume neutrino observatory that can also perform remote monitoring of nuclear reactors for nonproliferation. This paper describes the design and construction of the watertight optical modules of the experiment.

   ↳ physics.ins-dethep-exnucl-exEur.Phys.J.Plus(2026)·3 citations
5. 05*

   ENDF/B-VIII.1: Updated Nuclear Reaction Data Library for Science and Applications

   G.P.A. Nobre🇺🇸 · R. Capote🇦🇹 · M.T. Pigni🇺🇸 · A. Trkov🇸🇮 · C.M. Mattoon🇺🇸 · D. Neudecker🇺🇸 · D.A. Brown🇺🇸 · M.B. Chadwick🇺🇸 · A.C. Kahler🇺🇸 · N.A. Kleedtke🇺🇸 · M. Zerkle🇺🇸 · A.I. Hawari🇺🇸 and 97 other authors

   The ENDF/B-VIII.1 library is the newest recommended evaluated nuclear data file by the Cross Section Evaluation Working Group (CSEWG) for use in nuclear science and technology applications, and incorporates advances made in the six years since the release of ENDF/B-VIII.0. Among key advances made are that the ${}^{239}$Pu file was reevaluated by a joint international effort and that updated ${}^{16,18}$O, ${}^{19}$F, ${}^{28-30}$Si, ${}^{50-54}$Cr, ${}^{55}$Mn, ${}^{54,56,57}$Fe, ${}^{63,65}$Cu, ${}^{139}$La, ${}^{233,235,238}$U, and ${}^{240,241}$Pu neutron nuclear data from the IAEA coordinated INDEN collaboration were adopted. Over 60 neutron dosimetry cross sections were adopted from the IAEA's IRDFF-II library. In addition, the new library includes significant changes for ${}^3$He, ${}^6$Li,${}^9$Be, ${}^{51}$V, ${}^{88}$Sr, ${}^{103}$Rh, ${}^{140,142}$Ce, Dy, ${}^{181}$Ta, Pt, ${}^{206-208}$Pb, and ${}^{234,236}$U neutron data, and new nuclear data for the photonuclear, charged-particle and atomic sublibraries. Numerous thermal neutron scattering kernels were reevaluated or provided for the very first time. On the covariance side, work was undertaken to introduce better uncertainty quantification standards and testing for nuclear data covariances. The significant effort to reevaluate important nuclides has reduced bias in the simulations of many integral experiments with particular progress noted for fluorine, copper, and stainless steel containing benchmarks. Data issues hindered the successful deployment of the previous ENDF/B-VIII.0 for commercial nuclear power applications in high burnup situations. These issues were addressed by improving the ${}^{238}$U and ${}^{239,240,241}$Pu evaluated data in the resonance region. The new library performance as a function of burnup is similar to the reference ENDF/B-VII.1 library. The ENDF/B-VIII.1 data are available in ENDF-6 and GNDS format at https://doi.org/10.11578/endf/2571019.

   ↳ physics.app-phnucl-exnucl-thNuclear Data Sheets Volume 210, May 2026,…·11 citations
6. 06*

   Impact of QCD Energy Evolution on Observables in Heavy-Ion Collisions

   Heikki Mäntysaari🇫🇮 · Björn Schenke🇺🇸 · Chun Shen🇺🇸 · Wenbin Zhao🇨🇳

   We study how the inclusion of energy dependence as dictated by quantum chromodynamic (QCD) small-$x$ evolution equations affects key observables in ultra-relativistic heavy-ion collisions. Specifically, we incorporate JIMWLK evolution into the IP-Glasma framework, which serves as the initial condition for a simulation pipeline that includes viscous relativistic hydrodynamics and a hadronic afterburner. This approach enables a consistent modeling of highly energetic nuclei across varying Bjorken-$x$ values, which are relevant for different collision energies and rapidity regions. In comparison to the standard IP-Glasma setup without small-$x$ evolution, we observe pronounced changes in particle multiplicities and spectral distributions, especially in smaller systems and at the highest available energies. We further explore effects on anisotropic flow observables and correlations between mean transverse momentum and elliptic flow. Our findings underscore the critical role of nonlinear QCD evolution in accurately modeling the early stages of heavy-ion collisions, as well as its implications for extracting transport properties of the quark-gluon plasma.

   ↳ nucl-thhep-phnucl-exPRC(2026)·2 citations
7. 07*

   Violation of the elliptic flow scaling of $f_0(980)$ in p-Pb collisions at the LHC

   Yili Wang🇨🇳 · Wenbin Zhao🇺🇸 · Che Ming Ko🇺🇸 · Feng-Kun Guo🇨🇳 · Ju-Jun Xie🇨🇳 · Huichao Song🇨🇳

   We investigate the production and elliptic flow of the $f_0(980)$ in high-multiplicity p-Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV using a hadronic coalescence model with the $K$ and $\bar{K}$ phase-space distributions provided by the Hydro-Coal-Frag hybrid model. Our results, which agree with the ALICE and CMS measurements, support the $K\bar{K}$ molecular interpretation of the $f_0(980)$ structure and show, however, a breakdown of the simple number-of-constituent (NC) scaling of its elliptic flow. The latter is in contrast to the deuteron elliptic flow, which exhibits a significantly better NC scaling when the same coalescence width parameter is used.

   ↳ nucl-thnucl-exEPJ Web Conf.(2026)·1 citation
8. 08*

   Probing the structure of $f_0(980)$ from the elliptic flow in p-Pb collisions at the LHC

   Yili Wang🇨🇳 · Wenbin Zhao🇨🇳 · Che Ming Ko🇺🇸 · Fengkun Guo🇨🇳 · Ju-Jun Xie🇨🇳 · Huichao Song🇨🇳

   The $f_0(980)$ is a light scalar meson whose internal structure remains under debate and investigation. Assuming that the $f_0(980)$ is a $K\bar{K}$ molecule that can only survive at the kinetic freeze-out of the evolving bulk matter, we implement the coalescence model to study its transverse momentum ($p_T$) spectra and elliptic flow ($v_2$) in high-multiplicity p-Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV. Using the well-tuned kaon phase-space distributions from the Hydro-Coal-Frag model, our $K\bar{K}$ coalescence calculations with reasonable values for the $f_0(980)$ radius successfully reproduce the elliptic flow measured by CMS over the range $0<p_T<12$ GeV and also agree with the $p_T$-spectra from ALICE. These results in heavy ion collisions are consistent with the $K\bar{K}$ molecular picture of the $f_0(980)$. We also find that the number-of-constituent scaling of $v_2$ for the $f_0(980)$ is violated in p-Pb collisions at the LHC because most $f_0(980)$ are produced from the coalescence of kaons that have different momenta. Our study demonstrates the necessity of realistic coalescence model calculations and also explains why the CMS interpretation of the $f_0(980)$ as an ordinary $q\bar{q}$ meson is no longer valid by interpreting the measured $v_2$ with a simple scaling formula based on the assumption of equal momentum coalescence. The investigation also provides a novel way to explore the internal structure of light exotic hadrons that can be abundantly produced in relativistic heavy and/or light ion collisions.

   ↳ nucl-thnucl-exPLB(2026)·0 citations
9. 09*

   Is The Trace Anomaly at its Minimum Value at Neutron Star Centers?

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

   While the equation of state (EOS) $P(\epsilon )$ of neutron star (NS) matter has been extensively studied, the EOS-parameter $\varphi =P/\epsilon$ or equivalently the dimensionless trace anomaly $\Delta =1/3-\varphi$, which quantifies the balance between pressure $P$ and energy density $\epsilon$, remains far less explored, especially in NS cores. Its bounds and density profile carry crucial information about the nature of superdense matter. Physically, the EOS-parameter $\varphi$ represents the mean stiffness of matter accumulated from the stellar surface up to a given density. Based on the intrinsic structure of the Tolman--Oppenheimer--Volkoff equations, we show that $\varphi$ decreases monotonically outward from the NS center, independent of any specific input NS EOS model. Furthermore, observational evidence of a peak in the speed-of-sound squared (SSS) density-profile near the center effectively rules out a valley and a subsequent peak in the radial profile of $\varphi$ at similar densities, reinforcing its monotonic decrease. These model-independent relations impose strong constraints on the near-center behavior of the EOS-parameter $\varphi$, particularly demonstrating that the mean stiffness (or equivalently $\Delta$) reaches a local maximum (minimum) at the center.

   ↳ astro-ph.HEhep-phhep-thnucl-ex+1PRD(2026)·5 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.