Fri·Aug 29, 2025Friday·August 29, 2025

1. 01*

   ${\Sigma }^{+}$ production in pp collisions at $\sqrt{s}=13$ TeV

   ALICE Collaboration

   The measurement of ${\Sigma }^{+}$ production in pp collisions at $\sqrt{s}=13$ TeV is presented. The measurement is performed at midrapidity in both minimum-bias and high-multiplicity pp collisions at $\sqrt{s}=13$ TeV. The ${\Sigma }^{+}$ is reconstructed via its weak-decay topology in the decay channel ${\Sigma }^{+}\to \mathrm{p}+{\pi }^0$ with ${\pi }^0\to \gamma +\gamma$. In a novel approach, the neutral pion is reconstructed by combining photons that convert in the detector material with photons measured in the calorimeters. The transverse-momentum ($p_{\mathrm{T}}$) distributions of the ${\Sigma }^{+}$ and its rapidity densities $\mathrm{d}N$/$\mathrm{d}y$ in both event classes are reported. The $p_{\mathrm{T}}$ spectrum in minimum-bias collisions is compared to QCD-inspired event generators. The ratio of ${\Sigma }^{+}$ to previously measured $\Lambda$ baryons is in good agreement with calculations from the Statistical Hadronization Model. The high efficiency and purity of the novel reconstruction method for ${\Sigma }^{+}$ presented here will enable future studies of the interaction of ${\Sigma }^{+}$ with protons in the context of femtoscopic measurements, which could be crucial for understanding the equation of state of neutron stars.

   nucl-exhep-exEPJC(2026)·1 citation
2. 02*

   First Evidence of Solar Neutrino Interactions on ${}^{13}$C

   SNO+ Collaboration: M. Abreu · A. Allega · M. R. Anderson · S. Andringa · D. M. Asner · D. J. Auty · A. Bacon · T. Baltazar · F. Barão · N. Barros · R. Bayes · E. W. Beier and 100 other authors

   The SNO+ Collaboration reports the first evidence of ${}^8\text{B}$ solar neutrinos interacting on ${}^{13}\text{C}$ nuclei. The charged current interaction proceeds through ${}^{13}\text{C}+{\nu }_e\to {}^{13}\text{N}+e^{-}$ which is followed, with a 10 minute half-life, by ${}^{13}\text{N}\to {}^{13}\text{C}+e^{+}+{\nu }_e.$ The detection strategy is based on the delayed coincidence between the electron and the positron. Evidence for the charged current signal is presented with a significance of 4.2$\sigma$. Using the natural abundance of ${}^{13}\text{C}$ present in the scintillator, 5.7 tonnes of ${}^{13}\text{C}$ over 231 days of data were used in this analysis. The 5.6${}_{-2.3}^{+3.0}$ observed events in the data set are consistent with the expectation of 4.7${}_{-1.3}^{+0.6}$ events. This result is the second real-time measurement of CC interactions of ${}^8\text{B}$ neutrinos with nuclei and constitutes the lowest energy observation of neutrino interactions on ${}^{13}\text{C}$ generally. This enables the first direct measurement of the CC ${\nu }_e$ reaction to the ground state of ${}^{13}\text{N}$, yielding an average cross section of $(16.1_{-6.7}^{+8.5}(\text{stat.}{)}_{-2.7}^{+1.6}(\text{syst.}))\times 10^{-43}$ cm${}^2$ over the relevant ${}^8\text{B}$ solar neutrino energies.

   nucl-exhep-exPRL(2025)·4 citations
3. 03*

   Spectral line-shape in collinear laser spectroscopy after atomic charge exchange

   Adam Dockery🇺🇸 · Kei Minamisono🇺🇸 · Alejandro Ortiz Cortes · Brooke Rickey🇺🇸

   Collinear laser spectroscopy experiments on fast, neutral beams have been extensively used for studies on short-lived radioactive nuclei, taking advantage of its high sensitivity. The resulting resonance line-shape is known to show significant distortion, due to the energy exchange during the charge-exchange neutralization process, which can cause large systematic uncertainty in the determined centroid. A model for the line shape was constructed and simulated to be compared to measured Al, Si, and Ni hyperfine spectra. It is shown that the distortion is caused mainly by the transfer of electron into many different energy levels in the projectile atom and subsequent decays, rather than secondary inelastic collisions, which were often assumed in the line shape analysis before. The model can also be applied to other projectile-alkali pairs, providing a reliable line-shape with less fitting parameters than conventional phenomenological models.

   ↳ physics.atom-phnucl-exSpectrochimica Acta Part B 233, 107280 (2…·1 citation
4. 04*

   Configuration mixing effects on neutrinoless $\beta \beta$-decay nuclear matrix elements

   Kosuke Nomura🇯🇵

   Mixing and coexistence of intrinsic nuclear shapes play an important role to determine the low-energy structure of heavy nuclei, and are expected to affect nuclear matrix elements (NMEs) of neutrinoless double beta ($0\nu \beta \beta$) decay. This problem is addressed in the interacting boson model with configuration mixing that is formulated by using the nuclear energy density functional theory. It is shown that significant amounts of mixing of normal and deformed intruder configurations are present in the ground and excited $0^{+}$ states in the even-even nuclei that are parent or daughter nuclei of the $0\nu \beta \beta$ decay. An illustrative application to the $0\nu \beta \beta$ decays of ${}^{76}$Ge, ${}^{96}$Zr, ${}^{100}$Mo, ${}^{116}$Cd, and ${}^{150}$Nd shows that the inclusion of the configuration mixing reduces the NMEs for most of the $0_1^{+}$ $\to$ $0_1^{+}$ $0\nu \beta \beta$ decays.

   ↳ nucl-thnucl-exPLB(2025)·3 citations
5. 05*

   $\Xi NN$ three-baryon force from SU(3) chiral effective field theory: A femtoscopic study

   Gen Uratsu🇯🇵 · Tokuro Fukui🇯🇵 · Kazuyuki Ogata🇯🇵

   Background: The development of SU(3) chiral effective field theory has opened the way to a systematic exploration of three-baryon forces (3BFs), a key ingredient in hypernuclear and dense matter physics. However, $\Xi NN$ 3BF based on SU(3) chiral EFT has not been studied until now. Purpose: We apply SU(3) chiral EFT to derive $\Xi NN$ potentials in momentum space. Then, we investigate how the $\Xi NN$ 3BF affects the correlation function of deuteron--${\Xi }^{-}$ pair created through heavy-ion collisions. Methods: To reduce the number of low-energy constants involved in the $\Xi NN$ potentials, we employ the decuplet saturation approximation, by which only two of them remain unconstrained. The deuteron--${\Xi }^{-}$ scattering is treated as an effective two-body problem with the $\Xi NN$ 3BF incorporated into the potential between the deuteron and ${\Xi }^{-}$. Results: We found that the effect of the $\Xi NN$ 3BF on the deuteron--${\Xi }^{-}$ correlation function is at most about 4\%. This small effect is not primarily due to the loosely-bound nature of the deuteron. Instead, this is because the deuteron and ${\Xi }^{-}$ interact with each other mainly at low momentum, corresponding to peripheral scattering, where the influence of the $\Xi NN$ 3BF is limited. Conclusions: Since the correlation function shows limited sensitivity to the short-range 3BF, complementary approaches may be necessary.

   ↳ nucl-thhep-phnucl-exPRC(2026)·0 citations
6. 06*

   Deep learning for jet modification in the presence of the QGP background

   Ran Li🇨🇳 · Yi-Lun Du🇨🇳 · Shanshan Cao🇨🇳

   Jet interactions with the color-deconfined QCD medium in relativistic heavy-ion collisions are conventionally assessed by measuring the modification of the distributions of jet observables with respect to their baselines in proton-proton collisions. Deep learning methods enable per-jet evaluation of these modifications, enhancing the use of jets as precision probes of the nuclear medium. In this work, we predict the jet-by-jet fractional energy loss $\chi$ for jets evolving through a quark-gluon plasma (QGP) medium using a Linear Boltzmann Transport (LBT) model. To approximate realistic experimental conditions, we embed medium-modified jets in a thermal background and apply Constituent Subtraction for background removal. Two network architectures are studied: convolutional neural networks (CNNs) using jet images, and dynamic graph convolutional neural networks (DGCNNs) using particle clouds. We find that CNNs achieve accurate predictions for background-free jets but degrade in the presence of the QGP background and remain below the background-free baseline even after background subtraction. In contrast, DGCNNs applied to background-subtracted particle clouds maintain high accuracy across the entire $\chi$ range, demonstrating the advantage of point-cloud-based graph neural networks that exploit full jet structure under realistic conditions.

   ↳ hep-phhep-exnucl-exnucl-thPRC(2026)·3 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.