Tue·Aug 5, 2025Tuesday·August 5, 2025

1. 01*

   Measurement of transverse $\Lambda$ and $\bar{\Lambda }$ hyperon polarization in $p$Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV

   LHCb collaboration: R. Aaij · A.S.W. Abdelmotteleb · C. Abellan Beteta · F. Abudinén · T. Ackernley · A. A. Adefisoye · B. Adeva · M. Adinolfi · P. Adlarson · C. Agapopoulou · C.A. Aidala · Z. Ajaltouni and 1140 other authors

   The transverse polarization of $\Lambda$ and $\bar{\Lambda }$ hyperons is measured in $p$Pb collisions collected by the LHCb experiment at a nucleon-nucleon center-of-mass energy of $5.02$ TeV. The polarization is averaged over hyperon transverse momentum in the ranges $0.15<p_T<6.00$ GeV/$c$, and Feynman-$x$ in the ranges $0.005<x_F<0.040$ (forward region) and $-0.10<x_F<-0.01$ (backward region) defined relative to the proton beam direction. The transverse polarization is found to be compatible with zero for both $\Lambda$ and $\bar{\Lambda }$ hyperons. The results are also measured as a function of $p_T$ and $x_F$ with no significant dependence on these variables observed. The results are compared with previous experimental measurements at different center-of-mass energies and collision environments.

   nucl-exhep-exPRD(2025)·6 citations
2. 02*

   Re-optimization of a deep neural network model for electron-carbon scattering using new experimental data

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

   We present an updated deep neural network model for inclusive electron-carbon scattering. Using the bootstrap model [Phys.Rev.C 110 (2024) 2, 025501] as a prior, we incorporate recent experimental data, as well as older measurements in the deep inelastic scattering region, to derive a re-optimized posterior model. We examine the impact of these new inputs on model predictions and associated uncertainties. Finally, we evaluate the resulting cross-section predictions in the kinematic range relevant to the Hyper-Kamiokande and DUNE experiments.

   ↳ hep-phcs.LGnucl-exnucl-thPRC(2025)·0 citations
3. 03*

   Electron Emissions and Hot spots in Dual-Phase LXe TPCs

   J. Va'vra🇺🇸

   Persistent photon and single-electron emissions - in the form of "electron trains" and localized "hot spots" - have been observed in multiple dual-phase liquid xenon (LXe) time projection chambers (TPCs), often persisting long after ionizing events. We show that these phenomena are naturally explained by photon-triggered single-electron emission from resistive mixed-oxide films on stainless-steel wires, which behave as leaky capacitors with long RC time constants at LXe temperature. Positive ions landing on these oxides can further enhance local fields and drive Malter-like electron emission. We outline the materials physics (Cr2O3 / Cr2O3-x / Cr(OH)3 mosaics), quantify expected time scales (~1 second under illumination), and demonstrate how small damaged regions with enhanced QE can produce persistent hot spots.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2026)·2 citations
4. 04*

   HPGe-Compton Net: A Physics-Guided CNN for Fast Gamma Spectra Analysis via Compton Region Learning

   Yanfeng Xie🇨🇳 · Yiming Weng · Soo Hyun Byun

   High Purity Germanium (HPGe) detectors have been golden standard for gamma spectrometry in Low level radioactive waste (LLW) analysis; however, their notable shortcoming is prolonged measurement durations for weak radioactive waste materials. The present study aimed to develop the HPGe Compton Net, a 1D Physics Guided CNN to accelerate LLW analysis by taking advantage of the entire response function of a HPGe detector for each radionuclide of interest, in contrast to the traditional methods that analyze only peak regions of the response. This acceleration is supported by two core innovative strategies: (a) Channel Prompt method, a feature enhancement incorporating additional physical information to guide the model to locate the designated radionuclide; (b) the specially designed database to achieve effective targeted feature learning. The performance evaluation carried out for test data set showed a five times reduction in measurement time compared to a conventional spectral analysis method while maintaining comparable precision. Compton perturbation tests confirmed the model's smart adaptive utilization of the Compton regions. The generalization testing of four LLW samples as the external validation set proved its superior performance in low count data with an average accuracy of 90% over 83% of the traditional method. Future work will focus on upgrading the HPGe Compton Net for practical applications.

   ↳ physics.ins-detnucl-exMach.Learn.Sci.Tech.(2025)·0 citations
5. 05*

   Eliminating beam-induced depolarizing effects in the hydrogen jet target for high-precision proton beam polarimetry at the Electron-Ion Collider

   F. Rathmann · A. Nass · K.O. Eyser · V. Shmakova · E.C. Aschenauer · G. Atoian · A. Cannavo · K. Hock · H. Huang · H. Lovelace · G. Mahler · J. Ritter and 7 other authors

   We analyze beam-induced depolarizing effects in the hydrogen jet target (HJET) at the Relativistic Heavy Ion Collider (RHIC) that has been used for absolute hadron beam polarimetry and shall be employed at the Electron-Ion Collider (EIC). The EIC's higher bunch repetition frequencies and shorter bunch durations shift beam harmonics to frequencies that can resonantly drive hyperfine transitions in hydrogen, threatening to depolarize the target atoms. Using frequency-domain analysis of beam harmonics and hyperfine transition frequencies, we establish a photon emission threshold above which beam-induced fields are too weak to cause significant depolarization. For EIC injection (\SI{23.5}{\GeV}) and flattop (\SI{275}{\GeV}), beam-induced depolarization through the bunch structure renders operation at the current RHIC magnetic guide field at the target of $B_0=\text{SI}120\text{milli}\text{tesla}$ untenable. Increasing the magnetic guide field at the target to $B_0\approx \text{SI}400\text{milli}\text{tesla}$ moves all hyperfine transition frequencies to at least three times the cutoff frequency, ensuring reliable absolute beam polarimetry with the required 1\% precision at the EIC.

   ↳ physics.acc-phnucl-exPhys.Rev.Accel.Beams(2026)·6 citations
6. 06*

   Tribute to Toshimitsu Yamazaki (1934-2025): Quest for Exotic Hadronic Matter

   Avraham Gal🇮🇱

   In this talk I pay tribute to Toshimitsu Yamazaki who died earlier this year. Yamazaki's leading contributions to Hadronic Physics, in particular to Strangeness Nuclear Physics in Japan and elsewhere, are well known. Two of the five Recurring Themes of his research, as listed in the Japan Academy site, are highlighted here: (i) Discovery of deeply bound pionic-atom states, and (ii) Search for kaonic nuclei -- Kaonic Proton Matter (KPM). I conclude by reviewing briefly my own recent work, confirming Farrar's conjecture that a deeply bound $H$ dibaryon is not ruled out by the weak-decay observation of $\Lambda \Lambda$ hypernuclei. However, the relatively long lifetime of such a deeply bound $H$ is much too short to qualify it for a Dark-Matter candidate.

   ↳ nucl-thhep-phnucl-exPoS(2026)·0 citations
7. 07*

   Commissioning of the NUCLEUS Experiment at the Technical University of Munich

   H. Abele🇦🇹 · G. Angloher🇩🇪 · B. Arnold🇦🇹 · M. Atzori Corona🇮🇹 · A. Bento🇩🇪 · E. Bossio🇫🇷 · F. Buchsteiner🇦🇹 · J. Burkhart🇦🇹 · F. Cappella🇮🇹 · M. Cappelli🇮🇹 · N. Casali🇮🇹 · R. Cerulli🇮🇹 and 48 other authors

   The NUCLEUS experiment aims to detect coherent elastic neutrino-nucleus scattering of reactor antineutrinos on CaWO${}_4$ targets in the fully coherent regime, using gram-scale cryogenic calorimeters. The experimental apparatus will be installed at the Chooz nuclear power plant in France, in the vicinity of two 4.25 GW${}_{\text{th}}$ reactor cores. This work presents results from the commissioning of an essential version of the experiment at the shallow Underground Laboratory of the Technical University of Munich. For the first time, two cryogenic target detectors were tested alongside active and passive shielding systems. Over a period of two months all detector subsystems were operated with stable performance. Background measurements were conducted, providing important benchmarks for the modeling of background sources at the reactor site. Finally, we present ongoing efforts to upgrade the detector systems in preparation for a technical run at Chooz in 2026, and highlight the remaining challenges to achieving neutrino detection.

   ↳ hep-exnucl-exphysics.ins-detPRD(2025)·12 citations
8. 08*

   Pulse Shape Discrimination Algorithms: Survey and Benchmark

   Haoran Liu🇺🇸 · Yihan Zhan🇨🇳 · Mingzhe Liu🇨🇳 · Yanhua Liu🇨🇳 · Peng Li🇨🇳 · Zhuo Zuo · Bingqi Liu🇺🇸 · Runxi Liu🇺🇸

   This review presents a comprehensive survey and benchmark of pulse shape discrimination (PSD) algorithms for radiation detection, classifying nearly sixty methods into statistical (time-domain, frequency-domain, neural network-based) and prior-knowledge (machine learning, deep learning) paradigms. We implement and evaluate all algorithms on two standardized datasets: an unlabeled set from a 241Am-9Be source and a time-of-flight labeled set from a 238Pu-9Be source, using metrics including Figure of Merit (FOM), F1-score, ROC-AUC, and inter-method correlations. Our analysis reveals that deep learning models, particularly Multi-Layer Perceptrons (MLPs) and hybrid approaches combining statistical features with neural regression, often outperform traditional methods. We discuss architectural suitabilities, the limitations of FOM, alternative evaluation metrics, and performance across energy thresholds. Accompanying this work, we release an open-source toolbox in Python and MATLAB, along with the datasets, to promote reproducibility and advance PSD research.

   ↳ cs.LGcs.AInucl-exphysics.app-ph+1Radiat.Meas.(2026)·1 citation
9. 09*

   Half-life Measurements of Highly Charged Radioisotopes by Nuclear Recoil in a Penning Trap

   Scott Moroch🇺🇸 · Carolyn Chun · Doug VanDerwerken · Ariana Shearin · Brian Beaudoin · Klaus Blaum🇩🇪 · Timothy Koeth

   We present a novel method for measuring the half-life of highly charged radioisotopes by non-destructive nuclear recoil detection in a Penning ion trap. A specific emphasis is placed on ${}^7\mathrm{B}{\mathrm{e}}^{3+}$, which plays a crucial role in stellar evolution and the production of solar neutrinos. The determination of the half-life is necessary to constrain the free electron capture rate in the solar environment, but is difficult to measure by existing techniques. Simulations of the sympathetic cooling of the recoiled daughter nuclei (${}^7\mathrm{L}{\mathrm{i}}^{3+}$) with the trapped cloud of ${}^7\mathrm{B}{\mathrm{e}}^{3+}$ demonstrate a decay detection efficiency of $99.5\%$. A statistical analysis of half-life measurements on ensembles containing hundreds of ions shows that a final statistical uncertainty of less than $5\%$ is achieved with only 500 measured decays. By coherent control of hyperfine populations in trapped ions, the fidelity of the technique we describe enables the direct measurement and manipulation of state-dependent decay branching ratios for the first time.

   ↳ physics.ins-detnucl-exquant-phPRResearch(2025)·0 citations
10. 10*

    Intermediate Silicon Tracker in sPHENIX at RHIC

    Cheng-Wei Shih🇹🇼

    The sPHENIX collaboration has been taking data since 2023 at the Relativistic Heavy Ion Collider in BNL to study the Quark-Gluon Plasma and cold Quantum Chromodynamics (QCD). The tracking system of sPHENIX consists of a time projection chamber, a MAPS-based vertex detector, and an intermediate silicon tracker (INTT). Together with the sPHENIX full barrel calorimeter system, the measurement of the heavy-flavor jets and the upsilon-state identification are enabled. INTT, surrounding the collision point azimuthally at approximately 10 cm away with two layers of silicon strip sensors, detects hit points in the intermediate area of the tracking system to enhance tracking precision. Thanks to the good timing resolution of INTT, it also provides timing information to corresponding hits of other tracking detectors. This capability eliminates pile-up events due to misidentifying bunch crossings. This proceeding discusses the achievements of INTT using Au+Au collision data taken in 2023, and the status of INTT commissioning with proton+proton collisions in 2024.

    ↳ physics.ins-detnucl-exEPJ Web Conf.(2025)·1 citation

* 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.