Fri·Feb 7, 2025Friday·February 7, 2025

1. 01*

   Multidisciplinary Science in the Multimessenger Era

   Eric Burns🇺🇸 · Christopher L. Fryer🇺🇸 · Ivan Agullo🇺🇸 · Jennifer Andrews · Elias Aydi · Matthew G. Baring · Eddie Baron · Peter G. Boorman · Mohammad Ali Boroumand · Eric Borowski · Floor S. Broekgaarden · Poonam Chandra and 73 other authors

   Astrophysical observations of the cosmos allow us to probe extreme physics and answer foundational questions on our universe. Modern astronomy is increasingly operating under a holistic approach, probing the same question with multiple diagnostics including how sources vary over time, how they appear across the electromagnetic spectrum, and through their other signatures, including gravitational waves, neutrinos, cosmic rays, and dust on Earth. Astrophysical observations are now reaching the point where approximate physics models are insufficient. Key sources of interest are explosive transients, whose understanding requires multidisciplinary studies at the intersection of astrophysics, gravity, nuclear science, plasma physics, fluid dynamics and turbulence, computation, particle physics, atomic, molecular, and optical science, condensed matter and materials science, radiation transport, and high energy density physics. This white paper provides an overview of the major scientific advances that lay at the intersection of physics and astronomy and are best probed through time-domain and multimessenger astrophysics, an exploration of how multidisciplinary science can be fostered, and introductory descriptions of the relevant scientific disciplines and key astrophysical sources of interest.

   ↳ astro-ph.HEgr-qcnucl-exnucl-th+17 citations
2. 02*

   Measurements of ${\rm Y}$ States Production in $\text{p+p}$ Collisions at $\sqrt{s}=500\mathrm{GeV}$ with STAR: Cross Sections, Ratios, and Multiplicity Dependence

   The STAR Collaboration

   We report measurements of ${\rm Y}(1S)$, ${\rm Y}(2S)$ and ${\rm Y}(3S)$ production in $\text{p+p}$ collisions at $\sqrt{s}=500\mathrm{GeV}$ by the STAR experiment in year 2011, corresponding to an integrated luminosity ${\mathcal{L}}_{int}=13\mathrm{p}{\mathrm{b}}^{-1}$. The results provide precise cross sections, transverse momentum ($p_T$) and rapidity ($y$) spectra, as well as cross section ratios for $p_{\mathrm{T}}<10GeV/c$ and $|y|<1$. The dependence of the ${\rm Y}$ yield on charged particle multiplicity has also been measured, offering new insights into the mechanisms of quarkonium production. The data are compared to various theoretical models: the Color Evaporation Model (CEM) accurately describes the ${\rm Y}(1S)$ production, while the Color Glass Condensate + Non-relativistic Quantum Chromodynamics (CGC+NRQCD) model overestimates the data, particularly at low $p_T$. Conversely, the Color Singlet Model (CSM) underestimates the rapidity dependence. These discrepancies highlight the need for further development in understanding the production dynamics of heavy quarkonia in high-energy hadronic collisions. The trend in the multiplicity dependence is consistent with CGC/Saturation and String Percolation models or ${\rm Y}$ production happening in multiple parton interactions modeled by PYTHIA8.

   ↳ hep-exnucl-exPRD(2025)·5 citations
3. 03*

   Three-body structures of low-lying nuclear states of ${}^8$Li

   E. Garrido🇪🇸 · A.S. Jensen

   The four nucleons in ${}^8$Li outside the $\alpha$-particle ($\alpha {=}^4$He) can be divided into pairs of one neutron ($n$) and 3 nucleons in the triton ($t{=}^3$H), or 2 in the deuteron ($d{=}^2$H) and two neutrons in a dineutron (${}^{2}n$). The corresponding three-body structures, $\alpha$+$t$+$n$ or $\alpha$+$d$+${}^{2}n$, are suggested to describe the bulk part of the low-energy ($<10$~MeV) states of ${}^8$Li. Several breakup thresholds influence the structures and possible decays. We calculate the three-body structures of the various $J^{\pi }$ states, where different clustering appear, e.g. ${}^7$Li*+$n$, ${}^6$Li*${+}^{2}n$, ${}^6$He*$+d$. The experimental ${}^8$Li spectrum can be reproduced with fine tuning by a three-body potential parameter. Three unobserved $0^{+}$ and an excited 2${}^{+}$ states are found. All states appear as bound states or resonances. The lowest or highest energies have cluster structures, $\alpha$+$t$+$n$ or $\alpha$+$d$+${}^{2}n$, respectively. We give calculated energy and width (if possible), geometry, and partial wave decomposition for all states.

   ↳ nucl-thnucl-exPRC(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.