Fri·Jan 31, 2025Friday·January 31, 2025

1. 01*

   Recent open heavy flavor studies for the Electron-Ion Collider

   Xuan Li🇺🇸

   The future Electron-Ion Collider (EIC) will operate a series of high-luminosity high-energy electron+proton ($e+p$) and electron+nucleus ($\text{e + A}$) collisions to study several fundamental questions in the high energy and nuclear physics field. Heavy flavor hadron and jet production at the EIC plays an important role in exploring both potential modification on the initial-state nuclear parton distribution functions (nPDFs) and final-state parton propagation and hadronization processes under different nuclear medium conditions. The current design of the EIC ePIC detector has good performance of vertex and track reconstruction, particle identification and energy determination in the pseudorapidity region of $-3.5<\eta <3.5$, which will enable a series of high precision heavy flavor hadron and jet measurements. Latest simulation studies of the projected nuclear modification factor $R_{eA}$ of heavy flavor jets and heavy flavor hadron inside jets in $e+p$ and $\text{e + Au}$ collisions at $\sqrt{s}=$ 28.6 GeV and 63.2 GeV as well as the projected statistical accuracy of inclusive and differential charm baryon over meson ratio measurements in $e+p$ collisions will be presented. The impacts of these proposed EIC measurements on constraining the heavy quark propagation properties in cold nuclear medium and exploring the heavy quark hadronization process will be discussed.

   nucl-exhep-exnucl-thphysics.ins-detPoS(2025)·3 citations
2. 02*

   $\beta$-delayed neutron spectroscopy of ${}^{85,86}$As with MONSTER at IGISOL

   A. Pérez de Rada Fiol (1)🇪🇸 · T. Martínez (1)🇪🇸 · D. Cano-Ott (1)🇪🇸 · H. Penttilä (2)🇫🇮 · J. Agramunt (3)🇪🇸 · V. Alcayne (1)🇪🇸 · A. Algora (3)🇪🇸 · S. Alhomaidhi (4 and 5)🇩🇪 · J. Äystö (2 and 6)🇫🇮 · K. Banerjee (7 and 8)🇮🇳 · O. Beliuskina (2)🇫🇮 · J. Benito (9)🇪🇸 and 26 other authors

   The $\beta$-delayed neutron emission in the ${}^{85,86}$As $\beta$-decays has been measured at the Ion Guide Isotope Separator On Line facility of the Accelerator Laboratory of the University of Jyväskylä. The complete $\beta$-decays have been studied with a complex setup that consists of a plastic scintillator for $\beta$-particles, MONSTER -- the MOdular Neutron time-of-flight SpectromeTER -- for neutrons, and a high-purity germanium and four LaBr${}_3$ crystals for $\gamma$-rays. The $\beta$-delayed neutron energy distributions have been determined by unfolding the time-of-flight spectra with an innovative methodology based on the iterative Bayesian unfolding method and accurate Monte Carlo simulations. The results obtained for ${}^{85}$As are in excellent agreement with the existing evaluated data, validating the proposed methodology. In the case of ${}^{86}$As, a stronger neutron intensity at higher energies than previously predicted is discovered.

   nucl-exPRC(2025)·1 citation
3. 03*

   Updated analysis of neutron magnetic form factor and the nucleon transverse densities

   T. J. Hague (1 and 2)🇺🇸 · J. Arrington (1)🇺🇸 · J. Jayne (3)🇺🇸 · G. A. Miller (4)🇺🇸 · S. N. Santiesteban (3)🇺🇸 · Z. Ye (5) ((1) Lawrence Berkeley National Laboratory, (2) Thomas Jefferson National Accelerator Facility, (3) University of New Hampshire, (4) University of Washington, (5) Tsinghua University)🇨🇳

   We provide an updated global extraction of the neutron magnetic form factor, including new extractions from ${}^3$H-${}^3$He comparisons at Jefferson Lab. Our new global fit addresses discrepancies between previous data sets at modest momentum transfer by separating the uncertainties from world data into normalization and uncorrelated uncertainties. We use this updated global fit, along with previous fits for the other form factors, to extract the neutron and proton transverse charge and magnetization densities and their uncertainties.

   nucl-ex2 citations
4. 04*

   Branching ratio and information entropy for the p+${}^{12}$C reaction in the extended-quantum-molecular-dynamics model

   Lei Shen · Bo-Song Huang · Yu-Gang Ma🇨🇳

   The reactions of p+${}^{12}$C with triangular 3$\alpha$ structure and spherical structure with incident energies ranging from 5 to 200 MeV/nucleon are simulated by the in the extended-quantum-molecular-dynamics (EQMD) model together with the GEMINI decay process. This paper presents the incident energy dependence of the branching ratios of fragment production and multiplicity, as well as the associated event information entropy. The results indicate that the triangular 3$\alpha$ ${}^{12}$C has an extra branching ratio for the quasi-elastic reaction compared to the spherical ${}^{12}$C. This peculiarity of the branching ratios of the triangular 3$\alpha$ ${}^{12}$C appears as a small dent in the curves of the event information entropy (both the fragment information entropy and the multiplicity information entropy). Therefore, we propose that the event information entropy could be a probe for detecting the $\alpha$-cluster structure.

   ↳ nucl-thnucl-exPRC(2025)·0 citations
5. 05*

   Description of di-hadron saturation signals within a universal nuclear parton distribution function approach

   Dennis V. Perepelitsa🇺🇸

   Di-hadron and di-jet correlation measurements in proton-nucleus ($p$+A) and electron--nucleus collisions are widely motivated as sensitive probes of novel, non-linear QCD saturation dynamics in hadrons, which are particularly accessible in the dense nuclear environment at low values of Bjorken-$x$ ($x_{\mathrm{A}})$. Current measurements at RHIC and the LHC observe a significant suppression in the per-trigger yield at forward rapidities compared to that in proton-proton collisions, nominally consistent with the "mono-jet" production expected in a saturation scenario. However, the width of the azimuthal correlation remains unmodified, in contradiction to the qualitative expectations from this physics picture. I investigate whether the construction of these observables leaves them sensitive to effects from simple nuclear shadowing as captured by, for example, universal nuclear parton distribution function (nPDF) analyses. I find that modern nPDF sets, informed by recent precision measurements sensitive to the shadowing of low-$x_{\mathrm{A}}$ gluon densities in LHC and other data, can describe all or the majority of the di-hadron/jet suppression effects in $p$+A data at both RHIC and the LHC, while giving a natural explanation for why the azimuthal correlation width is unmodified. Notably, this is achieved via a $(x_{\mathrm{A}},Q^2)$-differential suppression of overall cross-sections only, without requiring additional physics dynamics which alter the inter-event correlations.

   ↳ nucl-thnucl-exPRC(2025)·4 citations
6. 06*

   Unpaired Translation of Point Clouds for Modeling Detector Response

   Mingyang Li🇨🇳 · Michelle Kuchera🇺🇸 · Raghuram Ramanujan🇺🇸 · Adam Anthony🇺🇸 · Curtis Hunt🇺🇸 · Yassid Ayyad🇪🇸

   Modeling detector response is a key challenge in time projection chambers. We cast this problem as an unpaired point cloud translation task, between data collected from simulations and from experimental runs. Effective translation can assist with both noise rejection and the construction of high-fidelity simulators. Building on recent work in diffusion probabilistic models, we present a novel framework for performing this mapping. We demonstrate the success of our approach in both synthetic domains and in data sourced from the Active-Target Time Projection Chamber.

   ↳ cs.CVcs.LGnucl-ex0 citations
7. 07*

   Novel Scalings of Neutron Star Properties from Analyzing Dimensionless Tolman--Oppenheimer--Volkoff Equations

   Bao-Jun Cai🇨🇳 · Bao-An Li🇺🇸

   The TOV equations govern the radial evolution of pressure and energy density in static neutron stars (NSs) in hydrodynamical equilibrium. Using the reduced pressure and energy density with respect to the NS central energy density, the original TOV equations can be recast into dimensionless forms. While the traditionally used integral approach for solving the original TOV equations require an input nuclear Equation of State (EOS), the dimensionless TOV equations can be anatomized by using the reduced pressure and energy density as polynomials of the reduced radial coordinate without using any input nuclear EOS. Interesting and novel perspectives about NS core EOS can be extracted directly from NS observables using this new approach based on Intrinsic and Perturbative Analyses of the Dimensionless (IPAD) TOV equations (IPAD-TOV). In this review, we first discuss the length and energy density scales of NSs as well as the dimensionless TOV equations for scaled variables and their perturbative solutions near NS cores. We then review several new insights into NS physics gained from using the IPAD-TOV. We also demonstrate that the strong-field gravity plays a fundamental role in extruding a peak in the density/radius profile of the speed of sound squared (SSS) in massive NS cores independent of the nuclear EOS. Finally, some future perspectives of NS research using the IPAD-TOV are outlined.

   ↳ astro-ph.HEastro-ph.SRgr-qcnucl-ex+1EPJA(2025)·25 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.