Nuclear Theory·nucl-th

Friday·September 4, 2026

11 papers—6 primary·5 cross-listed

07
Quantum Complexity in Nuclear Scattering and Fission Dynamics
Saurabh V. Kadam🇺🇸 · Antonio Bjelčić🇺🇸 · Nicolas Schunck🇺🇸 · Kyle Wendt🇺🇸
Quantum computers promise advantages for simulating strongly correlated quantum many-body systems, like atomic nuclei, that are beyond the reach of classical computers. Realizing this potential requires understanding the quantum complexity structure of the target problem. We investigate the time-evolution of two key indicators of quantum complexity, bipartite entanglement entropy and non-local magic (non-stabilizerness), in nuclear reaction dynamics. We analyze two representative dynamical processes: scattering in a one-dimensional model of strongly interacting fermions governed by the Negele potential, and a realistic simulation of $^{240}$ Pu fission within time-dependent Hartree-Fock-Bogoliubov (TDHFB) theory. In the former case, we find that interactions dynamically generate both entanglement and non-local magic, leaving persistent signatures of quantum complexity in the outgoing states. In the latter, we observe that substantial quantum complexity survives in the spatial bipartition of daughter fragments well beyond scission. The presence of significant non-local magic and entanglement in both cases strongly indicate that quantum computers would provide substantial advantages for accurately simulating nuclear reaction dynamics.
↳ quant-phnucl-th0 citations
08
CGC-py: A Monte Carlo Event Generator for Gluon Saturation Physics
Haowu Duan🇨🇳 · Cong Yi🇨🇳 · Si-Wei Dai🇨🇳 · Shu-Yi Wei🇨🇳 · Wenbin Zhao🇨🇳 · Liang Zheng🇨🇳
We develop CGC-py, a Monte Carlo event generator for deep-inelastic scattering. It couples the full Color Glass Condensate (CGC) cross section for $γ^{*} p (A) \to q q ˉ + X$ to a Parton-Branching transverse-momentum-dependent backward initial-state shower, while \textsc{Pythia}~8 handles final-state radiation and hadronization. CGC-py retains the complete target-elastic and target-inelastic contributions without taking the back-to-back correlation limit, allowing single- and di-hadron observables to be generated consistently from the same event sample. We validate the generator through an analytic closure test of the single-inclusive quark spectrum and a comparison of charged-hadron spectra in $e p$ collisions with H1 data, finding excellent agreement. The predicted nuclear modification factor $R_{e Au}^{h}$ shows the expected saturation pattern: suppression at low $p_{T}^{*}$ followed by a rise toward unity at higher $p_{T}^{*}$ . A comparison with a \textsc{Pythia}~6 baseline, together with an $x_{g}$ -rescaling study, indicates that small- $x$ CGC evolution and collinear DGLAP dynamics contribute comparably to the growth of the dihadron away-side width with energy. Genuine saturation-driven broadening emerges only at the highest energies considered. Within CGC-py, $e Au$ collisions exhibit an enhanced away-side width and a suppressed back-to-back yield relative to $e p$ collisions. These nuclear effects remain modest over EIC kinematics, motivating measurements at the most forward accessible kinematics and the use of complementary observables to maximize sensitivity to gluon saturation.
↳ hep-phhep-exnucl-exnucl-th0 citations
09
Ultra-compact twin stars with hybrid equations of state from bosonic dark matter
Ishfaq Ahmad Rather🇩🇪 · Sarah Louisa Pitz🇩🇪 · Jürgen Schaffner-Bielich🇩🇪
The properties of compact stars with a strong first-order phase transition to quark matter and with an additional fluid of self-interacting bosonic dark matter (DM) are studied. We find that the inclusion of DM changes considerably the stability of mass-radius configurations relative to the naive one-fluid criterion. For compact star configurations with similar masses and different radii, so-called twin stars, the presence of DM removes the unstable segment between the hadronic and the hybrid branch, so that the stable mass-radius sequence becomes continuous after the onset of the phase transition to quark matter. We furthermore find stable ultra-compact objects (UCOs), defined by a total compactness $C = M_{tot} / R_{grav} \geq 1/3$ . We observe two distinct classes of UCOs: a DM-halo class with $f_{DM} ≳ 0.9$ , and a DM-core class at $f_{DM} ≲ 0.02$ . The two classes can be separated by the surface redshift of the normal matter, which reaches $z = 0.73$ -- $0.77$ for the DM-core class and stays below $0.45$ for the DM-halo class. Finally, we find hybrid star solutions of 'ultimate twins' with similar mass and visible radius, but different dark matter content, leading to different tidal deformabilities and surface redshifts. Future X-ray and gravitational measurements of ultra-compact neutron stars with radii and masses outside the allowed neutron star range can thereby probe the presence and the properties of DM in addition to a first-order phase transition to quark matter.
↳ astro-ph.HEhep-phnucl-th0 citations
10
TQ4Q2.0 Fragmentation Functions for Fully Heavy Tetraquark Production
Francesco Giovanni Celiberto🇪🇸
We investigate the fragmentation dynamics underlying the production of fully heavy tetraquarks by means of the TQ4Q2.0 collinear FF set, covering scalar ( $0^{++}$ ), axial-vector ( $1^{+-}$ ), and tensor ( $2^{++}$ ) configurations. The fragmentation inputs are determined within NRQCD factorization for the complete set of relevant partonic channels and are subsequently evolved across heavy-flavor thresholds through the HF-NRevo scheme. Perturbative uncertainties associated with fragmentation-scale variations are consistently propagated together with nonperturbative effects encoded in color-composite long-distance matrix elements. Attention is devoted to the axial-vector sector, whose fragmentation pattern makes it especially sensitive to intrinsic-charm contributions at LHC and FCC energies. TQ4Q2.0 therefore provides an uncertainty-aware framework for exploring fully heavy tetraquark production over a broad kinematic range and for connecting exotic-hadron spectroscopy with the partonic structure of the proton.
↳ hep-phhep-exnucl-exnucl-th0 citations
11
First Two-Hadron Form Factor from QCD
Felipe G. Ortega-Gama🇺🇸 · Raúl A. Briceño🇺🇸 · Ivan M. Burbano🇺🇸 · Robert G. Edwards🇺🇸
We present the first QCD determination of an energy-dependent form factor for a two-hadron scattering state. In particular, we calculate the QCD contribution to the forward electromagnetic $π^{+} π^{+} + γ \to π^{+} π^{+}$ amplitude at $m_{π} \approx 400$ ~MeV using lattice QCD. Because lattice calculations are performed in a finite Euclidean spacetime, where asymptotic scattering states are absent, this amplitude cannot be accessed directly from correlation functions. Instead, we can constrain this and related amplitudes nonperturbatively using a finite-volume formalism that requires two ingredients: the discrete finite-volume spectrum and finite-volume matrix elements of the electromagnetic current. We calculate three-point correlation functions coupling $π^{+} π^{+}$ finite-volume states and extract the corresponding electromagnetic matrix elements. Combining these results with the previously determined spectrum, we constrain the infinite-volume $π^{+} π^{+} + γ \to π^{+} π^{+}$ amplitude in the forward limit. Using constraints from Lorentz symmetry, unitarity, and analyticity, we describe this amplitude in terms of a single real-valued energy-dependent two-hadron form factor. The resulting amplitude and form factor agree with the Ward-Takahashi identity across all energies and moving frames considered, providing the first QCD validation of this finite-volume approach and a pathway toward first-principles studies of the electromagnetic structure and electroweak responses of resonances and multi-hadron bound states.
↳ hep-lathep-phnucl-th0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Quantum Complexity in Nuclear Scattering and Fission Dynamics

CGC-py: A Monte Carlo Event Generator for Gluon Saturation Physics

Ultra-compact twin stars with hybrid equations of state from bosonic dark matter

TQ4Q2.0 Fragmentation Functions for Fully Heavy Tetraquark Production

First Two-Hadron Form Factor from QCD

Affiliations