Thu·Oct 31, 2024Thursday·October 31, 2024

1. 01*

   Azimuthal Anisotropy Scaling Functions for Identified Particle and Anti-Particle Species across Beam Energies: Insights into Baryon Junction Effects

   Roy A. Lacey (Department of Chemistry, Stony Brook University, Stony Brook, NY)🇺🇸

   Azimuthal anisotropy scaling functions are constructed from species-resolved anisotropy measurements in Pb+Pb ($\sqrt{s_{NN}}$=2.76, 5.02~TeV) and Au+Au ($\sqrt{s_{NN}}$=7.7--200~GeV) collisions to probe baryon transport and medium response at finite baryon chemical potential (${\mu }_B$). Within this data-driven framework, meson and baryon anisotropies spanning the collective-flow and quenching regimes collapse onto common scaling curves, enabling quantitative separation of viscous attenuation, radial flow, and hadronic re-scattering. The attenuation scale $k_{\beta }$ exhibits a non-monotonic beam-energy dependence, coincident with the low-energy rise of hadronic re-scattering, consistent with a temperature-dependent specific shear viscosity featuring a near-minimum near the QCD critical region. A charge-odd baryon--antibaryon separation in the effective radial-flow response is negligible at LHC energies but grows toward lower $\sqrt{s_{NN}}$. This species-uniform, baryon-number-scaling separation across $p,\Lambda ,\Xi ,\Omega$, and $d$ disfavors a purely hadronic origin and supports junction-driven net-baryon transport at finite ${\mu }_B$, enhancing the experimental visibility of critical dynamics in finite, rapidly evolving systems. Together, these results establish species-resolved scaling functions as a compact and robust tool for constraining baryon stopping, medium opacity, and QGP transport properties.

   nucl-exhep-exhep-phnucl-thPLB(2026)·3 citations
2. 02*

   The Auger-Meitner Radioisotope Microscope: an instrument for characterization of Auger electron multiplicities and energy distributions

   Patrick R. Stollenwerk · Stephen H. Southworth · Francesco Granato · Amy Renne · Brahim Mustapha · Kevin G. Bailey🇺🇸 · Peter Mueller · Jerry Nolen · Thomas P. O'Connor🇺🇸 · Junqi Xie · Linda Young · Matthew R. Dietrich

   We describe a new instrument, the Argonne Auger Radioisotope Microscope (ARM), capable of characterizing the Auger electron emission of radionuclides, including candidates relevant in nuclear medicine. Our approach relies on event-by-event ion-electron coincidence, time-of-flight, and spatial readout measurement to determine correlated electron multiplicity and energy distributions of Auger decays. We present a proof-of-principle measurement with the ARM using X-ray photoionization of stable krypton beyond the K-edge and identify a bifurcation in the electron multiplicity distribution depending on the emission of K-LX electrons. Extension of the ARM to the characterization of radioactive sources of Auger electron emissions is enabled by the combination of two recent developments: (1) cryogenic buffer gas beam technology to introduce Auger emitters into the detection region with well-defined initial conditions, and (2) large-area micro-channel plate detectors with multi-hit detection capabilities to simultaneously detect multiple electrons emitted in a single decay. The ARM will generate new experimental data on Auger multiplicities that can be used to benchmark atomic relaxation and decay models. This data will provide insight into the low-energy regime of Auger electrons where intensity calculations are most challenging and experimental data is limited. In particular, accurate multiplicity data of the low-energy regime can be used to inform oncological dosimetry models, where electron energies less than 500 eV are known to be most effective in damaging DNA and cell membranes.

   ↳ physics.ins-detnucl-exphysics.atom-phphysics.med-phNew J.Phys.(2025)·0 citations
3. 03*

   Ab initio nuclear shape coexistence and emergence of island of inversion around $N=20$

   E. F. Zhou · C. R. Ding🇨🇳 · J. M. Yao🇨🇳 · B. Bally🇫🇷 · H. Hergert🇺🇸 · C. F. Jiao🇨🇳 · T. R. Rodríguez🇪🇸

   We extend a nuclear ab initio framework based on chiral two- and three-nucleon interactions to investigate shape coexistence and the degradation of the $N=20$ magic number in both even-even and odd-even magnesium isotopes. The quantum-number projected generator coordinate method, combined with the in-medium similarity renormalization group (IMSRG), is employed to compute their low-lying states. This approach reasonably reproduces the coexistence of weakly and strongly deformed states at comparable energies, and allows us to track the emergence of the $N=20$ island of inversion through the continuous IMSRG evolution of the chiral Hamiltonian. Our results indicate that the ground state of ${}^{33}$Mg with spin-parity $3/2^{-}$ is predominantly a strongly deformed configuration with $K^{\pi }=3/2^{-}$, while the lowest $7/2^{-}$ state is predicted to be a shape isomer, consisting of a mixture of weakly deformed configurations with different $K$ values. The results highlight the essential roles of both dynamical and static collective correlations in reproducing the ordering of nuclear states with distinct shapes.

   ↳ nucl-thnucl-exPLB(2025)·15 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.