Wed·Aug 13, 2025Wednesday·August 13, 2025

1. 01*

   Recent Highlights from the STAR Experiment

   Rutik Manikandhan🇺🇸

   We summarize the latest correlation and fluctuation measurements derived from the RHIC Beam Energy Scan-II (BES-II) data, collected by the STAR experiment. We will focus on the recent results of higher-order net-proton cumulants ($C_1-C_4$) in the energy range of 7.7 to 27 GeV Au+Au collisions. Furthermore, we will present measurements of transverse momentum correlations of charged particles, particularly focusing on 2-particle correlators and their dependency on centrality in 3.0 and 3.2 GeV Au+Au collisions.

   nucl-exhep-exhep-phPoS(2026)·0 citations
2. 02*

   On the High Excitation 7$\alpha$ De-exciting States in ${}^{28}$Si${}^{\ast }$

   J. B. Natowitz · X. G. Cao · A. Bonasera🇺🇸 · T. Depastas🇺🇸

   A direct comparison and analysis of published spectra for the 7$\alpha$ disassembly of ${}^{28}$Si projectiles excited in collisions with ${}^{12}$C at 35 MeV/u reveals significant agreement in the derived excitation energies of high excitation energy resonances observed in two different experiments, in contrast to some earlier conclusions reported in the literature. Many of the observed resonances have excitation energies consistent with those arrived at in recent theoretical investigations explicitly predicting the excitation energies and spins of toroidal nuclei. An AI-assisted application of well-established statistical filtering techniques reveals identical structures in all spectra investigated. Some additional peaks are observed. The possibility that they correspond to other favored geometries is discussed.

   nucl-exnucl-th0 citations
3. 03*

   $\text{Ab Initio}$ Exact Calculation of Strongly Correlated Nucleonic Matter

   Rongzhe Hu🇨🇳 · Shaoliang Jin🇨🇳 · Xin Zhen🇨🇳 · Haoyu Shang🇨🇳 · Junchen Pei🇨🇳 · Furong Xu🇨🇳 · Francesco Marino🇩🇪

   Dense nucleonic matter is of vital importance for understanding compact stars and inferring the transition into deconfined quark phase. We present $\text{ab initio}$ exact calculations of infinite nucleonic matter with the state-of-the-art full configuration-interaction quantum Monte Carlo method, enabling us to rigorously benchmark many-body methods and assess the degree to which the nucleonic matter is correlated. Our method has been numerically validated against exact diagonalization within a small model space. Calculations of nucleonic matter using chiral nuclear forces reveal that symmetric nuclear matter is strikingly strongly correlated, raising questions on previous $\text{ab initio}$ calculations of nuclear matter with many-body expansion truncations and offering insights into simultaneous descriptions of finite nuclei and infinite nucleonic matter from first principles.

   ↳ nucl-thastro-ph.HEnucl-exPRL(2026)·9 citations
4. 04*

   High-resolution multi-reflection time-of-flight mass spectrometer for exotic nuclei at IGISOL

   V.A. Virtanen🇫🇮 · T. Eronen🇫🇮 · A. Kankainen🇫🇮 · O. Beliuskina🇫🇮 · Z. Ge🇫🇮 · R.P. de Groote🇧🇪 · A. Jokinen🇫🇮 · M. Mougeot🇫🇮 · A. de Roubin🇫🇮 · J. Ruotsalainen🇫🇮 · J. Sarén🇫🇮 · A. Takkinen🇫🇮

   A Multi-Reflection Time-of-Flight Mass Spectrometer (MR-ToF-MS) has been commissioned at the Ion-Guide Isotope Separator On-Line (IGISOL) facility. It consists of six electrode pairs that form a nearly energy-isochronous potential and a pulsed drift-tube to trap the ions between the electrodes. Time-of-flight peak widths down to 22 ns full-width at half-maximum and mass-resolving powers of $\approx 1.5\times 10^5$ within 20 ms have been demonstrated. The obtained time-focus and mass-resolving power depend sensitively on the trapping energy, energy spread and the number of revolutions of the ions. The mass-resolving power is affected by the temporal and energy spread of the ions entering the MR-ToF-MS, and fluctuations in the electrode voltages due to temperature variations. The longitudinal emittance corresponding to the temporal and energy spread of ${}^{39}$K is estimated to be 175 eVns based on the data, close to the expected 186(10) eVns. The time-of-flight temperature sensitivity is found to be -5.55(30) ppm/K. In addition to atomic mass measurements of short-lived exotic nuclides, the MR-ToF-MS can be used as a fast mass separator for various other experiments at IGISOL and as an ion counter for laser spectroscopy and yield measurements.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2026)·4 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.