Wed·Jul 23, 2025Wednesday·July 23, 2025

1. 01*

   Symmetric-asymmetric collision comparison: disentangling nuclear structure and subnucleonic structure effects for small system flow

   Shengli Huang🇺🇸 · Jiangyong Jia🇺🇸 · Chunjian Zhang🇨🇳

   Previous flow measurements in small collision systems were mostly based on highly asymmetric collisions ($p$+Pb, $p$+Au, $d$+Au, ${}^3$He+Au), where both nuclear structure and subnucleonic fluctuations are important. Comparing these asymmetric systems with the newly available symmetric ${}^{16}$O+${}^{16}$O collisions at RHIC and LHC provides a unique opportunity to disentangle these two contributions. Using Glauber models incorporating both nucleon and quark-level substructure, we analyze multiplicity distributions and initial-state estimators: eccentricities ${\epsilon }_n$ for anisotropic flow $v_n$ and inverse transverse size $d_{\perp }$ for radial flow. We find that subnucleonic fluctuations impact O+O collisions differently from asymmetric systems, creating specific patterns in flow observables that enable disentangling the competing contributions. Such experimental comparisons will reduce uncertainties in the initial conditions and improve our understanding of the properties of the QGP-like medium produced in small systems.

   ↳ nucl-thhep-phnucl-exPLB(2025)·6 citations
2. 02*

   The Automatic Calibration Method of the Compton Edge Based on Normalized Cross-correlation and Simulated Annealing Algorithm

   Dehua Kong · Yanbiao Zhang🇨🇳 · Zixi Lin🇺🇸 · Yehao Qiu🇩🇪 · Xiulian Chen🇨🇳 · Zhonghai Wang🇺🇸

   Accurate energy channel calibration in scintillation detectors is essential for reliable radiation detection across nuclear physics, medical imaging, and environmental monitoring. Organic scintillators like BC408 and EJ309 lack full-energy peaks, making their Compton edge a critical calibration alternative where traditional peak methods fail. Existing Compton edge identification techniques - Gaussian fitting for the 50%-70% amplitude point, first derivative minimum detection, and Monte Carlo simulation - suffer significant degradation from low count rates, spectral overlap, and subjective interval selection. For the first time, we propose an automated calibration procedure based on Normalized Cross-Correlation (NCC), Simulated Annealing (SA), and a convolutional response model to address these issues. This method automates the selection of the Compton edge interval through NCC-based matching, utilizes SA for global parameter optimization, and then employs a convolutional model for precise matching. Experiments involving the irradiation of organic scintillators (BC408, EJ309) and inorganic scintillators (NaI:Tl, LaBr3:Ce) with 137Cs, 22Na, 54Mn, and 60Co radiation sources demonstrate that this method achieves accuracy commensurate with full-energy peak calibration method (cosine similarity >99.999%) and exhibits superior stability compared to the two traditional methods. In the extreme cases of spectral overlap and low count rate, the average errors of this method are 19.77% and 15.65% of those from the two traditional methods in BC408, 56.44% and 33.15% of those from the two traditional methods in EJ309. This work advances detector calibration and offers a scalable, automated solution for high-energy experiments and portable devices.

   ↳ physics.ins-detnucl-ex0 citations
3. 03*

   Correlation function for the $n{\bar{D}}_{s0}^{\ast }(2317)$ interaction and the issue of elastic unitarity

   Natsumi Ikeno🇯🇵 · Eulogio Oset🇪🇸

   We study the interaction of a neutron with the ${\bar{D}}_{s0}^{\ast }(2317)$ resonance and look at the amplitude below threshold and close above threshold. The study is done from the perspective that the $D_{s0}^{\ast }(2317)$ resonance is a molecular state of $DK$ in $I=0$. To study this interaction, we use the Fixed Center Approximation to Faddeev equations that considers the $DK$ molecule as the cluster and the neutron as the external particle. We improve the Fixed Center approach to implement elastic unitarity around threshold, which is needed to obtain scattering parameters and to evaluate the $n{\bar{D}}_{s0}^{\ast }(2317)$ correlation function that we determine here. One interesting result of the study is the appearance of a resonant state below threshold with a binding of about 130 MeV and a width of about 80 MeV, which we suggest to look at in reactions measuring the invariant mass of $\pi \Sigma \bar{D}$. The ALICE collaboration has initiated studies of this type, by looking at the $p{f}_1(1285)$ correlation function, and we can only encourage work in this direction which should provide much valuable information on the nature of many resonant states.

   ↳ hep-phnucl-exnucl-thPRD(2025)·12 citations
4. 04*

   Alpha clustering in warm and dense nuclear matter from heavy-ion collisions

   Rui Wang🇮🇹 · Zhen Zhang🇨🇳 · Yu-Gang Ma🇨🇳 · Lie-Wen Chen🇨🇳 · Che Ming Ko🇺🇸 · Kai-Jia Sun🇨🇳

   Although light nuclear clusters are known to affect the properties of warm and dilute nuclear matter, their role in warm and dense nuclear matter remains unclear due to the lack of experimental evidence for their modifications by the Mott effect in such an environment. To address this issue, we resort to intermediate-energy heavy-ion collisions, where light clusters are mainly produced in the transiently formed warm and dense matter. A kinetic approach, which includes dynamically the formation and dissociation of light clusters, is employed to deduce the strength of the Mott effects and the $\alpha$-particle fraction in warm and dense nuclear matter from the light-nuclei yields measured by the FOPI Collaboration in central Au$+$Au collisions at energies of $0.25A$ to $0.6A\mathrm{GeV}$. We find an unexpectedly abundant $\alpha$ clustering in this environment, which will have profound implications for modeling the nuclear equation of state and describing supernovae and neutron star mergers.

   ↳ nucl-thastro-ph.HEnucl-exPRL(2026)·14 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.