Thu·Jan 2, 2025Thursday·January 2, 2025

1. 01*

   Comprehensive Measurement of the Reactor Antineutrino Spectrum and Flux at Daya Bay

   F. P. An · W. D. Bai · A. B. Balantekin · M. Bishai · S. Blyth · G. F. Cao · J. Cao · J. F. Chang · Y. Chang · H. S. Chen · H. Y. Chen · S. M. Chen and 190 other authors

   This Letter reports the precise measurement of reactor antineutrino spectrum and flux based on the full data set of 4.7 million inverse-beta-decay (IBD) candidates collected at Daya Bay near detectors. Expressed in terms of the IBD yield per fission, the antineutrino spectra from all reactor fissile isotopes and the specific ${}^{235}\mathrm{U}$ and ${}^{239}\mathrm{Pu}$ isotopes are measured with 1.3$\%$, 3$\%$ and 8$\%$ uncertainties respectively near the 3 MeV spectrum peak in reconstructed energy, reaching the best precision in the world. The total antineutrino flux and isotopic ${}^{235}\mathrm{U}$ and ${}^{239}\mathrm{Pu}$ fluxes are precisely measured to be $5.84\pm 0.07$, $6.16\pm 0.12$ and $4.16\pm 0.21$ in units of $10^{-43}\mathrm{c}{\mathrm{m}}^2/fission$. These measurements are compared with the Huber-Mueller (HM) model, the reevaluated conversion model based on the Kurchatov Institute (KI) measurement and the latest Summation Model (SM2023). The Daya Bay flux shows good consistency with KI and SM2023 models, but disagrees with HM model. The Daya Bay spectrum, however, disagrees with all model predictions.

   nucl-exhep-exPRL(2025)·20 citations
2. 02*

   Exploring QGP-like phenomena with Charmonia in $p+p$ collisions at $\sqrt{s}=13$ TeV

   Captain R. Singh🇮🇳 · Partha Bagchi🇮🇳 · Raghunath Sahoo🇮🇳 · Jan-e Alam🇮🇳

   In ultrarelativistic collisions of nuclei at the Large Hadron Collider, the created QCD environment rapidly changes, leading to a non-adiabatic evolution of the quantum states involved. Considering this, we first examine the pre-equilibrium state of QCD matter and its effect on the initially produced charmonium using a temperature-independent Hamiltonian. As the QCD matter reaches local thermal equilibrium, this Hamiltonian transforms to its finite temperature counterpart. To model the pre-equilibrium stage, we use the bottom-up thermalization approach to determine the effective temperature of the QCD matter, followed by a Gubser-type expansion for the thermalized medium. Additionally, we consider collisional damping, gluonic dissociation, and regeneration mechanisms, which specifically modify the charmonium yield in the thermalized medium. Mainly, the gluonic dissociation and collisional damping cause a reduction in the yield conversely, regeneration through gluonic deexcitation enhances the yield of charmonium. Further, we explore the combined effects of these mechanisms on the collective yield of charmonium states with transverse momentum ($p_{\mathrm{T}}$) and event multiplicity in the proton-proton collisions at $\sqrt{s}=13$ TeV. Based on our findings, we contend that the combined effects of these mechanisms can serve as a robust probe for determining the possible existence of a thermalized QCD medium in such a small collision system.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2025)·3 citations
3. 03*

   Isospin effect on the liquid-gas phase transition for finite nuclei

   S. Mallik🇮🇳

   The phenomenon of nuclear liquid-gas phase transition is a topic of contemporary interest. In heavy-ion collisions, there is no direct way of accessing the thermodynamic variables like pressure, density, free energy, entropy etc., and unambiguous detection of phase transition becomes difficult. A peak in the first order derivative of total multiplicity with respect to temperature (commonly abbreviated as the multiplicity derivative) has been established as a new experimentally accessible signature of the nuclear liquid-gas phase transition. In this work, the effect of isospin asymmetry in the fragmenting system, as well as the nuclear equation of state, on the multiplicity derivative and specific heat at constant volume is investigated within the framework of the Canonical Thermodynamical Model (CTM) with a semi-microscopic cluster functional.

   ↳ nucl-thhep-phnucl-exNPA(2025)·3 citations
4. 04*

   White Paper on Software Infrastructure for Advanced Nuclear Physics Computing

   P. M. Jacobs🇺🇸 · A. Boehnlein🇺🇸 · B. Sawatzky🇺🇸 · J. Carlson🇺🇸 · I. Cloet🇺🇸 · M. Diefenthaler🇺🇸 · R. G. Edwards🇺🇸 · K. Godbey🇺🇸 · W. R. Hix🇺🇸 · K. Orginos🇺🇸 · T. Papenbrock🇺🇸 · M. Ploskon🇺🇸 and 40 other authors

   This White Paper documents the discussion and consensus conclusions of the workshop "Software Infrastructure for Advanced Nuclear Physics Computing" (SANPC 24), which was held at Jefferson Lab on June 20-22, 2024. The workshop brought together members of the US Nuclear Physics community with data scientists and funding agency representatives, to discuss the challenges and opportunities in advanced computing for Nuclear Physics in the coming decade. Opportunities for sustainable support and growth are identified, within the context of existing and currently planned DOE and NSF programs.

   ↳ nucl-thhep-phnucl-ex3 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.