Tue·Oct 22, 2024Tuesday·October 22, 2024

1. 01*

   Binding energies, charge radii, spins and moments: odd-odd Ag isotopes and discovery of a new isomer

   B. van den Borne🇧🇪 · M. Stryjczyk🇫🇮 · R. P. de Groote🇫🇮 · A. Kankainen🇫🇮 · D.A. Nesterenko🇫🇮 · L. Al Ayoubi🇫🇮 · P. Ascher🇫🇷 · O. Beliuskina🇫🇮 · M.L. Bissell🇬🇧 · J. Bonnard🇬🇧 · P. Campbell🇬🇧 · L. Canete🇫🇮 and 24 other authors

   We report on the masses and hyperfine structure of ground and isomeric states in ${}^{114,116,118,120}$Ag isotopes, measured with the phase-imaging ion-cyclotron-resonance technique (PI-ICR) with the JYFLTRAP mass spectrometer and the collinear laser spectroscopy beamline at the Ion Guide Isotope Separator On-Line (IGISOL) facility, Jyväskylä, Finland. We measured the masses and excitation energies, electromagnetic moments, and charge radii, and firmly established the nuclear spins of the long-lived states. A new isomer was discovered in ${}^{118}$Ag and the half-lives of ${}^{118}$Ag long-lived states were reevaluated. We unambiguously pinned down the level ordering of all long-lived states, placing the inversion of the $I=0^{-}$ and $I=4^{+}$ states at $A=118$ $(N=71)$. Lastly, we compared the electromagnetic moments of each state to empirical single-particle moments to identify the dominant configuration where possible.

   nucl-exphysics.atom-phPRC(2025)·1 citation
2. 02*

   Enhanced $S$-factor for the ${}^{14}$N$(p,\gamma {)}^{15}$O reaction and its impact on the solar composition problem

   X. Chen · J. Su · Y. P. Shen · L. Y. Zhang · J. J. He · S. Z. Chen · S. Wang · Z. L. Shen · S. Lin · L. Y. Song · H. Zhang · L. H. Wang and 36 other authors

   The solar composition problem has puzzled astrophysicists for more than 20 years. Recent measurements of carbon-nitrogen-oxygen (CNO) neutrinos by the Borexino experiment show a $\sim 2\sigma$ tension with the "low-metallicity" determinations. ${}^{14}$N$(p,\gamma {)}^{15}$O, the slowest reaction in the CNO cycle, plays a crucial role in the standard solar model (SSM) calculations of CNO neutrino fluxes. Here we report a direct measurement of the ${}^{14}$N$(p,\gamma {)}^{15}$O reaction, in which $S$-factors for all transitions were simultaneously determined in the energy range of $E_p=110-260$ keV for the first time. Our results resolve previous discrepancies in the ground-state transition, yielding a zero-energy $S$-factor $S_{114}(0)=1.92\pm 0.08$ keV b which is 14% higher than the $1.68\pm 0.14$ keV b recommended in Solar Fusion III (SF-III). With our $S_{114}$ values, the SSM B23-GS98, and the latest global analysis of solar neutrino measurements, the C and N photospheric abundance determined by the Borexino experiment is updated to $N_{\mathrm{CN}}=({4.45}_{-0.61}^{+0.69})\times 10^{-4}$. This new $N_{\mathrm{CN}}$ value agrees well with latest "high-metallicity" composition, however, is also consistent with the "low-metallicity" determination within $\sim 1\sigma$ C.L., indicating that the solar metallicity problem remains an open question. In addition, the significant reduction in the uncertainty of $S_{114}$ paves the way for the precise determination of the CN abundance in future large-volume solar neutrino measurements.

   nucl-exastro-ph.SRPRL(2025)·4 citations
3. 03*

   Pair momentum dependence of tilted source in heavy ion collisions

   Yevheniia Khyzhniak🇺🇸 · Michael Annan Lisa🇺🇸

   In non-central heavy-ion collisions, the particle-emitting source can be tilted away from the beam direction, an effect that becomes particularly significant at collision energies of a few GeV and lower. This phenomenon, manifest itself in many observables such as directed flow, polarization, and vorticity, is therefore important to investigate. In this paper, we study the consistency between the tilt extracted directly from the freeze-out distribution of pions and the tilt parameter obtained using the azimuthally sensitive femtoscopy (asHBT) method. Using the UrQMD model, we demonstrate a strong dependence of the tilt parameter extracted with asHBT on the momentum of the particle pair. Considering the experimental challenges in accessing low particle momenta - where the tilt parameter extracted with asHBT closely matches the tilt of the freeze-out distribution of pions - we propose an exponential extrapolation method to obtain the tilt of the entire freeze-out distribution. This approach aims to enhance the accuracy of experimental measurements of tilt in non-central heavy-ion collisions.

   ↳ nucl-thhep-phnucl-exPRC(2025)·5 citations
4. 04*

   AutoFLUKA: A Large Language Model Based Framework for Automating Monte Carlo Simulations in FLUKA

   Zavier Ndum Ndum · Jian Tao · John Ford🇺🇸 · Yang Liu🇨🇳

   Monte Carlo (MC) simulations, particularly using FLUKA, are essential for replicating real-world scenarios across scientific and engineering fields. Despite the robustness and versatility, FLUKA faces significant limitations in automation and integration with external post-processing tools, leading to workflows with a steep learning curve, which are time-consuming and prone to human errors. Traditional methods involving the use of shell and Python scripts, MATLAB, and Microsoft Excel require extensive manual intervention and lack flexibility, adding complexity to evolving scenarios. This study explores the potential of Large Language Models (LLMs) and AI agents to address these limitations. AI agents, integrate natural language processing with autonomous reasoning for decision-making and adaptive planning, making them ideal for automation. We introduce AutoFLUKA, an AI agent application developed using the LangChain Python Framework to automate typical MC simulation workflows in FLUKA. AutoFLUKA can modify FLUKA input files, execute simulations, and efficiently process results for visualization, significantly reducing human labor and error. Our case studies demonstrate that AutoFLUKA can handle both generalized and domain-specific cases, such as Microdosimetry, with an streamlined automated workflow, showcasing its scalability and flexibility. The study also highlights the potential of Retrieval Augmentation Generation (RAG) tools to act as virtual assistants for FLUKA, further improving user experience, time and efficiency. In conclusion, AutoFLUKA represents a significant advancement in automating MC simulation workflows, offering a robust solution to the inherent limitations. This innovation not only saves time and resources but also opens new paradigms for research and development in high energy physics, medical physics, nuclear engineering space and environmental science.

   ↳ cs.AIhep-exnucl-exphysics.comp-ph+12 citations
5. 05*

   Test of $T$-invariance in scattering of polarized protons on tensor-polarized deuterons at energies of the NICA SPD

   Yu.N. Uzikov🇷🇺 · M.N. Platonova🇷🇺

   The effect of violation of $T$-invariance, provided that $P$-parity is preserved, is given by the total cross section of the interaction of a vector-polarized particle with a tensor-polarized target. A formalism for calculating this effect developed previously and based on the spin-dependent Glauber theory of elastic $pd$ scattering is used here to calculate the effect under discussion in the range of collision energies corresponding to the invariant mass of the $pN$ system $\sqrt{s_{pN}}=5$--$30$ GeV. The spin-dependent amplitudes of elastic $pN$ scattering required for this calculation are taken from existing phenomenological models for $pN$ scattering in the energy region considered.

   ↳ nucl-thhep-exhep-phnucl-exPhys.Part.Nucl.(2025)·2 citations
6. 06*

   Shell quenching in nuclear charge radii based on Monte Carlo dropout Bayesian neural network

   Zhen-Yan Xian · Yan Ya · Rong An

   Charge radii can be generally used to encode information about various fine structures of finite nuclei. In this work, a constructed Bayesian neural network based on the Monte Carlo dropout approach is proposed to accurately describe the charge radii of nuclei with proton number $Z\ge 20$ and mass number $A\ge 40$. More motivated underlying mechanisms are incorporated into this combined model in addition to the basic building blocks with the specific number of protons and neutrons, which naturally contain the pairing effect, the isospin effect, the shell closure effect associated with the Casten factor $P$, the valence neutrons, the valence protons, the quadrupole deformation ${\beta }_{20}$, the high order hexadecapole deformation ${\beta }_{40}$, and the local shape staggering effect of ${}^{181,183,185}$Hg. To avoid the distorted cases of the traditional Casten factor at the fully filled shells, the modified Casten factor $P^{\ast }$ is introduced into the input structure parameter sets. The standard root-mean-square deviation is reduced to $0.0084$ fm for the training data set and $0.0124$ fm for the validation data set with the modified Casten factor $P^{\ast }$. Meanwhile, the shell closure effect of nuclear charge radii can be reproduced remarkably well. We have successfully demonstrated the ability of this constructed model to significantly increase the accuracy in predicting the nuclear charge radii.

   ↳ nucl-thnucl-exPLB(2025)·6 citations
7. 07*

   Summary of Global Extraction of the ${}^{12}\mathrm{C}$ Nuclear Electromagnetic Response Functions and Comparisons to Nuclear Theory and Neutrino/Electron Monte Carlo Generators at Nufact24

   Arie Bodek🇺🇸 · M. E. Christy🇺🇸 · Zihao Lin🇺🇸 · Giulia-Maria Bulugean🇺🇸 · Amii Matamoros Delgado🇺🇸

   We present a brief report (at the Nufact-2024 conference) summarizing a global extraction of the ${}^{12}\mathrm{C}$ longitudinal (${\mathcal{R}}_L$) and transverse (${\mathcal{R}}_T$) nuclear electromagnetic response functions from an analysis of all available electron scattering data on carbon. Since the extracted response functions cover a large kinematic range they can be readily used for comparison to theoretical predictions as well as validation and tuning Monte Carlo (MC) generators for electron and neutrino scattering experiments. Comparisons to several theoretical approaches and MC generators are given in arXiv:2409.10637v1 [hep-ex]. We find that among all the theoretical models that were investigated, the ``Energy Dependent-Relativistic Mean Field'' (ED-RMF) approach provides the best description of both the Quasielastic (QE) and {\it nuclear excitation} response functions (leading to single nucleon final states) over all values of four-momentum transfer. he QE data are also well described by the "Short Time Approximation Quantum Monte Carlo" (STA-QMC) calculation which includes both single and two nucleon final states which presently is only valid for momentum transfer $0.3<\mathbf{q}<0.65$ GeV and does not include nuclear excitations. An analytic extrapolation of STA-QMC to lower $\mathbf{q}$ has been implemented in the GENIE MC generator for ${}^4\mathrm{He}$ and a similar extrapolation for ${}^{12}\mathrm{C}$ is under development. STA validity for $\mathbf{q}>$ 0.65 GeV requires the implementation of relativistic corrections. Both approaches have the added benefit that the calculations are also directly applicable to the same kinematic regions for neutrino scattering. In addition we also report on a universal fit to all electron scattering data that can be used in lieu of experimental data for validation of Monte Carlo generators (and is in the process of being implemented in GENIE).

   ↳ hep-exnucl-ex3 citations
8. 08*

   Locating the QCD critical point through contours of constant entropy density

   Hitansh Shah🇺🇸 · Mauricio Hippert🇧🇷 · Jorge Noronha🇺🇸 · Claudia Ratti🇺🇸 · Volodymyr Vovchenko🇺🇸

   We propose a new method to investigate the existence and location of the conjectured high-temperature critical point of strongly interacting matter via contours of constant entropy density. By approximating these lines as a power series in the baryon chemical potential ${\mu }_B$, one can extrapolate them from first-principle results at zero net-baryon density, and use them to locate the QCD critical point, including the associated first-order and spinodal lines. As a proof of principle, we employ currently available continuum-extrapolated first-principle results from the Wuppertal--Budapest collaboration to find a critical point at a temperature and a baryon chemical potential of $T_c=114.3\pm 6.9$ MeV and ${\mu }_{B,c}=602.1\pm 62.1$ MeV, respectively. We advocate for a more precise determination of the required expansion coefficients via lattice QCD simulations as a means of pinpointing the location of the critical endpoint in the phase diagram of strongly interacting matter.

   ↳ hep-phhep-latnucl-exnucl-thPRC(2026)·55 citations
9. 09*

   New Angles on Energy Correlators

   Samuel Alipour-fard🇺🇸 · Ankita Budhraja🇳🇱 · Jesse Thaler🇺🇸 · Wouter J. Waalewijn🇳🇱

   Energy correlators have recently come to the forefront of jet substructure studies at colliders due to their remarkable properties: they naturally separate physics at different scales, are robust to contamination from soft radiation, and offer a direct connection with quantum field theory. The current parametrization used for energy correlators, however, is based on redundant pairwise angles with complex phase space restrictions. In this Letter, we introduce a new parametrization of energy correlators that features a simpler phase space structure and preserves information about the orientation of jet constituents. Further, our parametrization drastically reduces the computational cost to compute energy correlators on experimental data; whereas the time to compute a traditional projected $N$-point energy correlator scales as $M^N/N!$ on a jet with $M$ particles, our new parametrization achieves a scaling of $M^2\log M$, remarkably independently of N. Even for N=3, this improved scaling is particularly important for studies of heavy ion collisions, and higher values of $N$ will enable new qualitative understanding of gauge theories. Theoretical calculations for our new energy correlators differ from those of traditional parametrizations only at next-to-next-to-leading logarithmic accuracy and beyond, and we expect that our simpler phase space structure will simplify those calculations. We also discuss how to extend our parametrization to resolved $N$-point energy correlators that encode angular distances between greater numbers of particles, yielding intuitive visualizations of jet substructure that are qualitatively different for different jet samples. We propose two possible generalizations for probing multi-prong jets and testing jet scaling behavior.

   ↳ hep-phhep-exnucl-exnucl-thPRL(2025)·21 citations
10. 10*

    Universality in the Near-Side Energy-Energy Correlator

    Xiaohui Liu🇨🇳 · Werner Vogelsang🇩🇪 · Feng Yuan🇺🇸 · Hua Xing Zhu🇨🇳

    We investigate the energy-energy correlator (EEC) of hadrons produced on the same side in $e^{+}{e}^{-}$ annihilation or in leading jets in $pp$ collisions. We observe a remarkable universality of the correlator. Using a non-perturbative transverse momentum dependent (TMD) fragmentation function to model the transition from the ``free-hadron" region to the perturbative collinear region, we are able to describe the near-side shapes and peaks over a wide range of energy for both the $e^{+}{e}^{-}$ annihilation and the $pp$ jet substructure measurements in terms of just two parameters. We present further predictions for the ratio of the projected three-point energy correlator to the EEC. The excellent agreement between our calculations and the experimental data may provide new insights into the role of non-perturbative physics for EECs, and suggests the possibility of exploring non-perturbative TMDs using theoretical tools developed for the energy correlators.

    ↳ hep-phhep-exnucl-exnucl-thPRL(2025)·32 citations
11. 11*

    A method to detect the VUV photons from cooled ${}^{229}$Th:CaF${}_2$ crystals

    Ming Guan · Michael Bartokos🇦🇹 · Kjeld Beeks🇨🇭 · Yuta Fukunaga · Takahiro Hiraki · Takahiko Masuda🇯🇵 · Yuki Miyamoto · Ryoichiro Okage · Koichi Okai · Noboru Sasao🇯🇵 · Fabian Schaden🇦🇹 · Thorsten Schumm🇦🇹 and 4 other authors

    Thorium-229, with its exceptionally low-energy nuclear excited state, is a key candidate for developing nuclear clocks. ${}^{229}$Th-doped CaF${}_2$ crystals, benefiting from calcium fluoride's wide band gap, show great promise as solid-state nuclear clock materials. These crystals are excited by vacuum ultraviolet (VUV) lasers, which over time cause radiation damage. Cooling the crystals can mitigate this damage but introduces a challenge: photoabsorption. This occurs when residual gas molecules condense on the crystal surface, absorbing VUV photons and deteriorating detection efficiency. To solve this, we developed a cooling technique using a copper shield to surround the crystal, acting as a cold trap. This prevents ice-layer formation, even at temperatures below $-100{}^{\circ }$C, preserving high VUV photon detection efficiency. Our study detailed the experimental cooling setup and demonstrated the effectiveness of the copper shield in maintaining crystal performance, a critical improvement for future solid-state nuclear clocks operating at cryogenic temperatures.

    ↳ physics.ins-detnucl-exNucl.Instrum.Meth.B(2025)·2 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.