Nuclear Theory·nucl-th

Tuesday·July 7, 2026

19 papers—11 primary·8 cross-listed

12
Subensemble Acceptance Method 3.0: General Corrections to Cumulants from Exact Conservation Constraints
Roman Poberezhniuk🇺🇸 · Volodymyr A. Kuznietsov🇺🇸 · Grégoire Pihan🇺🇸 · Volodymyr Vovchenko🇺🇸
We present the subensemble acceptance method 3.0 (SAM-3.0), which corrects cumulants of an observable measured in a subsystem of a large system for the effect of exact global conservation of multiple charges. The required input is the set of joint grand-canonical cumulants of the acceptance observable with the total event charges, from which the canonical cumulants follow algebraically via a closed recursion based on (multivariate) partial exponential Bell polynomials. The framework accommodates any number of observables, including non-conserved quantities such as net protons, and any number of simultaneously conserved charges, including the total energy, which yields the microcanonical ensemble. The mapping contains SAM-1.0 and SAM-2.0 as special cases and, unlike SAM-2.0, reproduces the exact binomial-acceptance limit. We also derive the leading finite-size corrections from the saddle-point expansion. We apply the method to update the hydrodynamics-based non-critical baseline (Hydro-EV) for net-proton cumulants at RHIC-BES energies, finding a refined baseline that agrees with direct canonical Monte Carlo sampling and stays close to the earlier SAM-2.0 result. We further validate the formalism against direct Monte Carlo sampling with exact simultaneous conservation of baryon number, electric charge, and strangeness, including hadronic-afterburner effects.
↳ hep-phnucl-th2 citations
13
Transverse-spin dependent energy-energy correlators in proton-proton collisions within the dihadron fragmentation framework
Zhong-Bo Kang🇺🇸 · Andreas Metz🇺🇸 · Daniel Pitonyak🇺🇸 · Congyue Zhang🇺🇸
We calculate energy-energy correlations for two hadrons produced inside a jet in transversely polarized proton-proton collisions. We make numerical predictions based on a simple model that utilizes a previous global QCD analysis of dihadron fragmentation and transversity parton distribution functions. The results show remarkable agreement with a very recent STAR measurement. We also find the data at large jet transverse momentum have a slight preference for extractions of transversity that are consistent with lattice QCD computations of the nucleon tensor charges. Overall, this work provides further evidence for the underlying non-perturbative mechanism of near-side energy-energy correlators as well as highlights the potential for these observables to probe transverse-spin effects inside the nucleon.
↳ hep-phhep-exnucl-exnucl-th0 citations
14
Studying baryon number transport dynamics via hyperon-kaon correlations in $p + Au$ collisions at $s_{_{NN}} = 20$ , $39$ and $62$ GeV
Siyuan Ping🇨🇳 · Xiaozhou Yu🇨🇳 · Long Ma🇨🇳
The observation of positive net hyperon baryon numbers at mid-rapidity in heavy-ion collisions indicates that baryon numbers from incident nucleons can be transported across a large rapidity gap to hyperons where strange quarks of $s - s ˉ$ are pair-produced. Consequently, hyperons and kaons are expected to be correlated, providing a sensitive probe of both baryon number transport mechanism and strange quark pair correlation. Such correlation may be used to test the gluon-junction interaction mechanism where a $Y$ -shaped gluonic field may carry the baryon number and be responsible for the baryon number transport to hyperons over a large rapidity gap. We present hyperon-kaon correlations as a function of their relative rapidity in $p + Au$ collisions at $s_{N N} = 20$ , $39$ , and $62$ GeV using a multiphase transport ( $AMPT$ ) model and Ultra-relativistic Quantum Molecular Dynamics ( $UrQMD$ ) models where hyperon-kaon pairs are originated from fragmentation scheme. We quantify the correlation function using the Wasserstein distance method and systematically investigate the correlation dependence on the beam energy, hyperon emission direction and detector acceptance. Our simulation results provide a baseline without the baryon junction mechanism for future experimental measurements.
↳ hep-phhep-exnucl-exnucl-th0 citations
15
Polarized Nucleon as a Topological Dipole
Kenji Fukushima🇯🇵 · Tomoya Uji🇯🇵
We show that a polarized nucleon generically carries a dipole distribution of topological charge density. This topological dipole follows robustly from the definition of the topological form factor and the pseudoscalar nature of the topological charge density. The strength of the topological dipole is fixed, in the chiral limit, by the flavor-singlet axial charge. We demonstrate the mechanism in a two-flavor chiral soliton model with vector mesons and the $U (1)_{A}$ anomaly, where the rotation of the soliton induces a singlet pseudoscalar profile and realizes the predicted dipole pattern. We also discuss possible experimental probes through exclusive $η$ , $η^{'}$ production and directed-flow-like pseudoscalar-meson asymmetries correlated with magnetic fields or vorticity in relativistic heavy-ion collisions.
↳ hep-phnucl-th0 citations
16
Measurement of isolated prompt photon production in $p$ + $p$ collisions at $s = 200$ GeV with the sPHENIX detector
sPHENIX Collaboration · M. I. Abdulhamid · U. Acharya · G. Adawi · I. Ahmed · C. A. Aidala · Y. Akiba · M. Alfred · A. Alsayegh · D. M. Anderson · V. V. Andrieux · A. Angerami and 88 other authors
The differential cross section of isolated prompt photon production is measured as a function of photon transverse energy ( $E_{T}^{γ}$ ) in proton--proton ( $p$ + $p$ ) collisions at $s = 200$ GeV. The data were recorded in $2024$ with the sPHENIX detector at the Relativistic Heavy Ion Collider. Photons are reconstructed in $∣ η^{γ} ∣ < 0.7$ and $12 < E_{T}^{γ} < 32$ GeV using the electromagnetic calorimeter, and an isolation requirement is imposed using both the electromagnetic and hadronic calorimeters. The measured cross section is compared with the PYTHIA Monte Carlo event generator and perturbative quantum chromodynamics (pQCD) calculations at next-to-leading and next-to-next-to-leading order. The pQCD calculations are consistent with the result within the quoted uncertainties. This measurement provides a test of pQCD calculations for a process with sensitivity to the gluon parton distribution function of the proton and establishes the $p$ + $p$ baseline for forthcoming sPHENIX measurements of isolated prompt photons in heavy-ion collisions.
↳ nucl-exnucl-th1 citation
17
ML and AI for density functional theory: different priorities for Kohn-Sham and orbital-free DFT, for electronic and nuclear DFT
Xin-Hui Wu · Sergei Manzhos
We overview similarities and, importantly, differences in computational bottlenecks and accuracy requirements that can be addressed with machine learning (ML) and artificial intelligence (AI) techniques in electronic and nuclear DFT. From these follow different promising methodological and algorithmic choices depending on whether one machine learns the exchange correlation (XC) functional, the kinetic energy functional (KEF), the density or the basis functions. In particular, while the popular deep neural networks remain a potent choice in the context of KS DFT, we highlight their disadvantages when building KEFs and highlight conceptual advantages - yet to be fully realized - of symbolic regression for both electronic and nuclear DFT. We point out promising approaches that can be carried from the more extensively investigated ML-enhanced electronic DFT to nuclear DFT.
↳ physics.chem-phcond-mat.mtrl-scinucl-thquant-ph0 citations
18
Exclusive Quark and Gluon Dijet Production as Probes of GPDs at Collider Energies
Zhuoyi Pang (NCBJ, Warsaw) · Paweł Sznajder (NCBJ, Warsaw) · Lech Szymanowski (NCBJ, Warsaw) · Jakub Wagner (NCBJ, Warsaw)
We study exclusive electroproduction of dijets in the collinear factorization framework as a probe of generalized parton distributions (GPDs). For quark dijet production, we extend previous analyses by including contributions from helicity GPDs and by assessing an additional leading-order electromagnetic channel governed by elastic nucleon form factors. Furthermore, we investigate exclusive gluon dijet production. We compare our prediction to HERA data and provide projections for measurements at the future Electron-Ion Collider.
↳ hep-phhep-exhep-thnucl-th1 citation
19
Structure of Anisotropic Magnetized Neutron Stars in f(R,T) Gravity with Realistic Equation of State
M. Savari · G. H. Bordbar · J. Sedaghat · A. Sheykhi
In this study, within the framework of f(R,T) modified gravity, we investigate the influence of coupling parameter, magnetic field and anisotropy parameter on the neutron star structure. This work employs an accurate equation of state (EoS), derived from realistic microscopic calculations based on the AV18 nucleon-nucleon potential, to compute the structure of this compact object. Here, determination of Schwarzschild radius, compactness, gravitational surface redshift and Kretschmann scalar within the f(R, T) gravity, confirms that our theoretical results are consistent with the observational constraints. While established physical EoSs within the framework of Einstein gravity have successfully characterized a broad range of compact objects, they remain inadequate in explaining certain massive objects residing within the mass gap (2.5 to 5 Msun). We show that some compact objects residing in the mass gap interpreted as candidates of neutron stars within the framework of f(R, T) gravity. Finally, we compare our results with the observational data from LIGO/Virgo/KAGRA and NICER, setting the parameters of the f(R, T) theory and anisotropy to successfully reproduce the masses and radii of the GW170817, PSR J0952-0607 and PSR J0740+6620 and the masses of the secondary components of GW190814 and GW200210-092254.
↳ gr-qcastro-ph.SRnucl-thPLB(2026)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE