Fri·May 2, 2025Friday·May 2, 2025

1. 01*

   Hard-jet correlations in large and small systems

   Riccardo Longo🇺🇸

   Hard-jet correlations probe parton energy loss and the microscopic structure of the quark-gluon plasma formed in ultra-relativistic heavy-ion collisions. The correlation of high-$p_{\mathrm{T}}$ jets with other jets, hadrons, or electroweak bosons, offers differential sensitivity to medium-induced effects such as momentum broadening, color decoherence, and medium response in different types of nuclear reactions. Such correlations can also be used to study cold nuclear matter effects arising in $p$+A collisions. This proceeding summarizes recent advances achieved by studying hard-jet correlations in large and small systems discussed at Hard Probes 2024, complementing the experimental jet overview.

   nucl-exEPJ Web Conf.(2025)·0 citations
2. 02*

   Measuring ${}^{241}$Am Dipole Response

   C. Scarlett🇺🇸 · E. Fischbach🇺🇸 · B. Freeman🇺🇸 · J. J. Coy🇺🇸 · P. Edwards🇺🇸 · D. Osborne🇺🇸 · J. Edwards🇺🇸 · L. Mwibanda🇺🇸 · A. Alsayegh🇺🇸

   Americium (${}^{241}$Am) with an unpaired proton in the F${}_{5/2}$ state exhibits a significant magnetic dipole moment. The dipole can be experimentally measured with application of even modest external magnetic fields, as little as 1G, as a shifting in the energy spectrum of emitted gammas during the process of decaying to ${}^{237}$Np ground state. This paper looks at the shifting in the output energy peak of gammas from the decay of excited ${}^{237}$Np when two configurations of an external magnetic field are applied. The peak shifting, which does not appear in the background data dominated by ${}^{238}$U decays, differs for the two dominant gammas released at 26.3 keV and 59.5 keV. For the 59.5 keV peak: shifting is ~ 32% of 1-Energy Bin or about 0.5 keV. While for the 26.3 keV peak: shifting is ~ 15% of 1-Energy Bin or about 0.24 keV. Interestingly enough, there appears to be a shifting for the case where the field remains in a direction horizontal to the optical bench and the light is simply blocked or unblocked from entering the field, referred to as the light (sP) or dark (sD) modes.

   nucl-ex0 citations
3. 03*

   Bayesian Inference of Hybrid Star Properties from Future High-Precision Measurements of Their Radii

   Bao-An Li🇺🇸 · Xavier Grundler🇺🇸 · Wen-Jie Xie🇨🇳 · Nai-Bo Zhang🇨🇳

   Future high-precision X-ray and gravitational-wave observations of neutron stars (NSs) are expected to constrain NS radii with uncertainties as small as $\sigma \simeq 0.1$~km. Such unprecedented precision offers a unique opportunity to extract new information about the nature and equation of state (EOS) of supradense matter in NS cores. Using mock radius data with uncertainties ranging from $\sigma =1.0$ to $0.1$~km, together with a flexible meta-model NS EOS that allows for a first-order hadron-quark phase transition, we perform a Bayesian statistical analysis to assess the impact of radius measurements on EOS constraints. We find that high-precision radius measurements, particularly for massive NSs, significantly tighten constraints on the hadron-quark transition density ${\rho }_t$, the quark matter mass fraction in NS cores, and several parameters characterizing the EOS of supranuclear hadronic matter, although the degree of improvement depends on the assumed prior range of ${\rho }_t$. In contrast, even with the highest precision considered, NS radii -- including those of massive stars -- remain largely insensitive to the stiffness of quark matter, independent of the measurement accuracy or the prior range adopted for ${\rho }_t$.

   ↳ astro-ph.HEastro-ph.GAhep-phnucl-ex+1ApJ(2026)·16 citations
4. 04*

   Neutron Star Radii from Laboratory Experiments

   M. D. Cozma🇷🇴 · W. Trautmann🇩🇪

   Our present knowledge of the nuclear equation of state is briefly reviewed in this article intended for a wider readership. Particular emphasis is given to the asymmetric-matter equation of state required for modeling neutron stars, neutron-star mergers, and r-process nucleosynthesis. Recent analyses based on combining information obtained from nuclear theory, heavy-ion collisions and astrophysical observations confine the obtained radii of the canonical 1.4-solar-mass neutron star to values between 12 km and 13 km. The remaining uncertainty is primarily related to missing information in the density interval between nuclear saturation density and about twice that value which, however, is accessible with laboratory experiments.

   ↳ nucl-thastro-ph.SRnucl-exIJMPE(2025)·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.