Thu·Aug 14, 2025Thursday·August 14, 2025

1. 01*

   Coulomb excitation of ${}^{124}$Te: Emerging collectivity and persisting seniority structure in the $6_1^{+}$ level

   M. Reece🇦🇺 · B. J. Coombes🇦🇺 · A. J. Mitchell🇦🇺 · A. E. Stuchbery🇦🇺 · G. J. Lane🇦🇺 · A. Gargano🇮🇹 · V. U. Bashu🇦🇺 · L. J. Bignell🇦🇺 · C. Gautam🇺🇸 · L. J. McKie🇦🇺 · N. J. Spinks🇦🇺 · J. A. Woodside🇦🇺

   The low-lying energy spectra of even-even tellurium isotopes near midshell have long been interpreted as `textbook' examples of vibrational collective motion. However, in many cases electric-quadrupole observables, which are a particularly sensitive probe of collectivity, remain undetermined. Coulomb-excitation measurements were performed to measure transition strengths connecting the ground and low-excitation states in ${}^{124}$Te. This isotope lies at a transitional point between collective structure near the neutron midshell and seniority structures near the $N=82$ shell. A transition strength, $B(E2;6_1^{+}\to 4_1^{+})$, of 27(9)~W.u. was measured for the $6_1^{+}\to 4_1^{+}$ transition for the first time in this nucleus; this value is significantly below that expected for a spherical vibrator, as well as other collective models. We examine the transition strengths in ${}^{124}$Te and its neighbors by comparison with large-basis shell-model calculations and by comparison with General Collective Model (GCM) fits. A GCM description of ${}^{120}$Te agrees with experimental $E2$ transition strengths, but no comparable description of ${}^{124}$Te is possible with the GCM. In contrast, there is remarkably good agreement between the $B(E2;6_1^{+}\to 4_1^{+})$ values and shell-model calculations for ${}^{124-134}$Te. It appears that, despite approaching midshell, ${}^{124}$Te retains a seniority structure for the $6_1^{+}$ level, i.e. a significant $\pi 0g_{7/2}^2$ contribution. This persistence of the shell structure at the $6_1^{+}$ state is in contrast to the $B(E2)$ values of the lower-excitation $2_1^{+}$ and $4_1^{+}$ states in ${}^{124}$Te, and neighboring ${}^{120}$Te and ${}^{122}$Te, for which the collectivity becomes enhanced as more neutrons are removed from $N=82$.

   nucl-exnucl-thPRC(2025)·3 citations
2. 02*

   First direct access to the ${\rho }^0$p interaction via correlation studies at the LHC

   ALICE Collaboration

   Direct measurements of the ${\rho }^0$p interaction have remained so far elusive, with most insights derived indirectly from photoproduction or low-energy partial wave analyses. This letter presents the first direct observation of the ${\rho }^0$p interaction, obtained through two-particle correlations measured in high-multiplicity, ultrarelativistic proton-proton collisions at $\sqrt{s}=13$ TeV by the ALICE Collaboration at the LHC. Two-particle correlation data, analyzed within chiral effective field theory ($\chi$EFT) using a coupled-channel approach and incorporating recent $\varphi$-p data, yield a scattering length of $a_{{\rho }^{0}p}=(-0.46\pm 0.04)+i(0.20\pm 0.04)$ fm and constrain coupling strengths of two states identified with the N(1958) and N(1700). These findings emphasize the importance of coupled-channel dynamics and dynamically generated states in understanding the ${\rho }^0$p interaction. The results establish a vacuum baseline for extrapolation studies to high densities, contributing to the foundation for chiral symmetry restoration searches, and offer collider-based insights into the QCD spectrum, complementing traditional low-energy approaches. This work marks a significant advance in correlation studies, extending the exploration of interactions to the most short-lived QCD states.

   nucl-exhep-ex4 citations
3. 03*

   Machine Learning Power Week 2023: Clustering in Hadronic Calorimeters

   Muaz Al Halabi🇩🇪 · Marcel Bajdel🇩🇪 · Jeroen Peter Bormans🇩🇪 · Hannah Bossi (ed)🇺🇸 · Maria Calmon Behling🇩🇪 · Florian Ehmann🇩🇪 · Niklas Gotz🇩🇪 · Jerome Jung🇩🇪 · Rafet Kavak🇩🇪 · Mario Krüger🇩🇪 · Robin Lakos🇩🇪 · Annemarie Lauterbach🇩🇪 and 10 other authors

   In both high-energy physics and industry applications, a crowd-sourced approach to difficult problems is becoming increasingly common. These innovative approaches are ideal for the development of future facilities where the simulations can be publicly distributed, such as the Electron-Ion Collider (EIC). In this paper, we discuss a so-called ``Power Week" where graduate students were able to learn about machine learning while also contributing to an unsolved problem at a future facility. Here, the problem of interest was the clustering of the forward hadronic calorimeter in the foreseen electron-proton/ion collider experiment (ePIC) detector at the EIC. The different possible approaches, developed over the course of a single week, and their performance are detailed and summarised. Feedback on the format of the week and recommendations for future similar programs are provided in the hopes to inspire future learning opportunities for students that also serve as a crowd-sourced approaches to unsolved problems.

   nucl-exhep-ex0 citations
4. 04*

   Multiplicity dependence of ${\Xi }_c^{+}$ and ${\Xi }_c^0$ production in pp collisions at $\sqrt{s}=13$ TeV

   ALICE Collaboration

   The first measurement at midrapidity ($|y|<0.5$) of the production yield of the strange-charm baryons ${\Xi }_c^{+}$ and ${\Xi }_c^0$ as a function of transverse momentum ($p_{\mathrm{T}}$) in different charged-particle multiplicity classes in proton-proton collisions at $\sqrt{s}=13$ TeV with the ALICE experiment at the LHC is reported. The ${\Xi }_c^{+}$ baryon is reconstructed via the ${\Xi }_c^{+}\to {\Xi }^{-}{\pi }^{+}{\pi }^{+}$ decay channel in the range $4<p_{\mathrm{T}}<12$ GeV/$c$, while the ${\Xi }_c^0$ baryon is reconstructed via both the ${\Xi }_c^0\to {\Xi }^{-}{\pi }^{+}$ and ${\Xi }_c^0\to {\Xi }^{-}{e}^{+}{\nu }_e$ decay channels in the range $2<p_{\mathrm{T}}<12$ GeV/$c$. The baryon-to-meson (${\Xi }_c^{0,+}/{\mathrm{D}}^0$) and the baryon-to-baryon (${\Xi }_c^{0,+}/{\Lambda }_{\mathrm{c}}^{+}$) production yield ratios show no significant dependence on multiplicity. In addition, the observed yield ratios are not described by theoretical predictions that model charm-quark fragmentation based on measurements at $e^{+}{e}^{-}$ and $e^{-}$p colliders, indicating differences in the charm-baryon production mechanism in pp collisions. A comparison with different event generators and tunings, including different modelling of the hadronisation process, is also discussed. Moreover, the branching-fraction ratio of BR(${\Xi }_c^0\to {\Xi }^{-}{e}^{+}{\nu }_e$)/BR(${\Xi }_c^0\to {\Xi }^{-}{\pi }^{+}$) is measured as 0.825 $\pm$ 0.094 (stat.) $\pm$ 0.081 (syst.). This value supersedes the previous ALICE measurement, improving the statistical precision by a factor of 1.6.

   nucl-exhep-exJHEP(2025)·4 citations
5. 05*

   Extracting temperature of plasma through fusion reactions within a transport approach

   Zhe Zhu🇨🇳 · Jun Xu🇨🇳

   We have investigated the method of extracting the temperature from weighted proton-to-neutron yield ratio from fusion reactions as in the previous experiment~[W. Bang, {\it et al.}, Phys. Rev. Lett. \textbf{111}, 055002 (2013).] using the Texas Petawatt laser beam. The Coulomb explosion of deuterium clusters is simulated based on the particle-in-cell model in a box system with periodic boundary conditions, and fusion reactions are incorporated through the stochastic method. As long as the deuteron numbers in deuterium clusters follow a log-normal distribution, the low-energy part of the final deuteron spectrum can be fitted by a Maxwell-Boltzmann distribution, while there are more deuterons in the intermediate- and high-energy region compared to a thermal distribution, and dominate the weighted yield ratio. Therefore, the effective temperature extracted from the weighted yield ratio is generally higher than that from fitting the final deuteron spectrum. The local density fluctuation, which intrinsically exists due to the log-normal distribution of deuteron numbers, further enhances hot deuteron-deuteron collisions, and significantly affects the weighted yield ratio.

   ↳ physics.plasm-phnucl-exnucl-thPhys.Plasmas(2025)·0 citations
6. 06*

   Spectral function approach in NuWro: modeling of multinucleon final states in quasielastic scattering

   Artur M. Ankowski🇵🇱 · Rwik Dharmapal Banerjee🇵🇱 · Jan T. Sobczyk🇵🇱 · José L. Bonilla🇵🇱 · Krzysztof M. Graczyk🇵🇱 · Beata E. Kowal🇵🇱 · Hemant Prasad🇵🇱

   Neutrino-oscillation experiments performed in the few-GeV energy region create an urgent demand for a significant improvement in the accuracy of modeling of neutrino interactions with atomic nuclei. Here, we report an updated implementation of the spectral function approach in the \nuwro{} Monte Carlo generator, which consistently treats multinucleon final-states in quasielastic scattering at the inclusive and exclusive level. After validating its accuracy against inclusive electron-scattering data, we compare its predictions to various neutrino cross sections from MicroBooNE. We find that with the multinucleon contribution, these data are reproduced with ${\chi }^2$ per degree of freedom of 1.3--1.8, compared to 2.7--7.2 without it.

   ↳ hep-phnucl-exnucl-th4 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.