Nuclear Theory·nucl-th

Thursday·April 16, 2026

9 papers—2 primary·7 cross-listed

01
Scattering lengths beyond the nuclear scale and the Efimov effect
F. Miguel Marqués🇫🇷
The interaction of neutrons and nuclei at low energies may potentially lead to scattering lengths several orders of magnitude larger than the effective range of the interaction, well beyond the nuclear scale. If such cases existed, they could lead to the observation of the Efimov effect in nuclei, a remarkable universal phenomenon that has been observed only in atoms. The interaction parameters of neutrons scattering off unstable nuclei can be explored in neutron-nucleus systems created after the fast removal of a few nucleons from a slightly heavier beam. The case of the $^{17}$ B- $n$ system is considered, and the implications of its potentially huge scattering length on the structure of $^{19}$ B as a $^{17}$ B- $n$ - $n$ Efimov trimer are discussed.
nucl-thnucl-ex0 citations
02
Non-Gaussian fluctuations in relativistic hydrodynamics: Confluent equations for three-point correlations
Xin An · Gokce Basar · Mikhail Stephanov
We derive deterministic equations for the evolution of non-Gaussian fluctuations in relativistic stochastic hydrodynamics. This is achieved by defining the average local Landau frame and corresponding fluctuating hydrodynamic variables. Fully nonlinear stochastic hydrodynamics is expressed in a unified multi-component matrix form. A novel relativistic formalism, also manifestly covariant under SO(3) rotations of the local spatial basis in the average local Landau frame, is introduced. The equations describe correlators of all hydrodynamic variables, including fluctuating velocity (or momentum density) -- a nontrivial problem in relativistic hydrodynamics.
nucl-thcond-mat.stat-mechhep-th3 citations
03
Proton Structure from Neural Simulation-Based Inference at the LHC
Ricardo Barrué🇦🇹 · Lisa Benato🇦🇹 · Ali Kaan Güven🇦🇹 · Elie Hammou🇳🇱 · Jaco ter Hoeve🇬🇧 · Claudius Krause🇦🇹 · Ang Li🇦🇹 · Luca Mantani🇪🇸 · Juan Rojo🇳🇱 · Sergio Sánchez Cruz🇪🇸 · Robert Schöfbeck🇦🇹 · Maria Ubiali🇬🇧 · Daohan Wang🇦🇹
The precise determination of the parton distribution functions (PDFs) of the proton is an essential ingredient for LHC analyses, including for those at the upcoming High-Luminosity LHC. So far, PDFs are determined from global fits to binned low-dimensional data obtained from unfolded hard-scattering cross section measurements. In this work we demonstrate for the first time the feasibility of neural simulation-based inference (NSBI) for constraining the proton PDFs using a high-dimensional unbinned data set. Exploiting the full statistical power of unbinned data removes the loss of information inherited by the binning procedure. As a proof-of-concept, we determine the gluon PDF from simulated data of top quark pair production at the LHC with $s = 13$ TeV. Taking into account both experimental and theoretical systematic uncertainties in the detector-level features, we demonstrate how the NSBI pipeline achieves significant improvements in precision compared to existing low-dimensional binned analyses. Our results illustrate the potential of unbinned inference to reduce the reliance on coarse approximations of uncertainties and their correlations entering PDF determinations, hence contributing to a new paradigm of unbinned detector-level ML-assisted measurements at the LHC.
↳ hep-phhep-exnucl-exnucl-th3 citations
04
Quantum computing for effective nuclear lattice model
Zhushuo Liu🇨🇳 · Jia-ai Shi🇨🇳 · Bing-Nan Lu🇨🇳 · Xiaosi Xu🇨🇳
Nuclear lattice effective field theory has become an important framework for quantum many-body calculations in nuclear physics, yet its classical implementation remains increasingly challenging for more general interactions and larger systems. In this work, we develop a quantum-computing framework for a three-dimensional nuclear lattice model. We construct a variational quantum eigensolver framework and systematically compare the Jordan-Wigner and Gray code encodings. Our analysis shows that for the few-body systems considered here, Gray code combined with symmetry reduction yields a substantially more compact qubit representation. Based on this framework, we perform numerical studies for $^{2} H$ , $^{3} H$ , and $^{4} He$ on finite lattices. The calculated ground-state energies exhibit a clear approach toward the corresponding experimental binding energies as the lattice size increases. These results provide a proof-of-principle foundation for future quantum simulations of nuclear many-body problems.
↳ quant-phnucl-th0 citations
05
Response theory for quantum fields in isolation
Stefan Floerchinger🇩🇪
Response theory describes the reaction of observales to perturbations in external fields. We review this formalism for quantum fiels in isolation that have unitary time evolution. An emphasis is put on consequences of causality and the resulting spectral representations for linear and nonlinear response functions, on functional techniques and generating functionals, including the description of the initial state, the evolution, and measurements. We review consequences of time reversal symmetry and relations for the statistics of work, and discuss a large class of quantum correlation functions, and their relation to response functions through fluctuation-dissipation relations. Consequences of conservation laws and gauge symmetries are mentioned briefly.
↳ quant-phhep-thnucl-th1 citation
06
Global polarization of $Λ$ hyperons in hot QCD matter at TeV energies
Bhagyarathi Sahoo🇮🇳 · Captain R. Singh🇮🇳 · Raghunath Sahoo🇮🇳
The study of spin polarization of $Λ$ hyperons in ultrarelativistic heavy-ion collisions provides insights into the angular momentum and vortical structure of the possible existence of QGP. The present study examines the global spin polarization of $Λ$ hyperons using a second-order relativistic viscous hydrodynamic framework that incorporates medium vorticity, shear viscosity, and evolving magnetic fields. It explores thermal vorticity evolution in relativistic heavy-ion collisions and evaluates its value at the decoupling isothermal freeze-out surface. We quantify the contributions of thermal vorticity and magnetic field to the global spin polarization of $Λ$ hyperons. Comparing results with recent ALICE measurements in Pb+Pb collisions at $s_{N N}$ = 2.76 and 5.02 TeV shows qualitative agreement, offering new insights into the vortical structure of QCD matter. It also explores the relationship between magnetic and rotational dynamics, with implications for spin polarization at RHIC and LHC energies.
↳ hep-phhep-exhep-thnucl-ex+11 citation
07
Spectroscopy of $^{11}$ Be from the $^{10}$ Be( $d, p$ ) reaction measured in inverse kinematics by the AT-TPC in SOLARIS
M. Z. Serikow · D. Bazin · M. A. Caprio · Y. Ayyad · S. Beceiro-Novo · J. Chen · M. Cortesi · M. DeNudt · S. Giraud · P. Gueye · S. Heinitz · C. R. Hoffman and 12 other authors
The spectroscopy of $^{11}$ Be is explored using the $^{10}$ Be $(d, p)$ $^{11}$ Be transfer reaction performed in inverse kinematics at $9.6 \MeV / u$ using the Active Target Time Projection Chamber (AT-TPC) inside the SOLARIS solenoid. This experiment is the first attempt at coupling the AT-TPC with SOLARIS to perform a high luminosity transfer reaction measurement without compromising excitation energy and scattering angle resolutions. The angular momentum transfer for states up to $3.40 \MeV$ are determined from distorted-wave Born approximation analysis of the measured angular distributions, from which the corresponding spectroscopic factors are deduced. These factors are compared with those from various shell model interactions, and those for the $3.40 \MeV$ state are consistent with a positive parity assignment. Recent \textit{ab initio} no-core configuration interaction (NCCI) calculations with various nucleon-nucleon interactions are presented for the low-lying positive parity states of $^{11}$ Be. The excitation energies produced using the Daejeon16 interaction are in good agreement with those found from both this experiment and the literature, thus supporting a positive parity assignment. The $3.40 \MeV$ state, if assigned a tentative $J^{π} = 3/ 2^{+}$ , would then correspond to the second excited state of the $K^{P} = 1/ 2^{+}$ one-neutron halo ground state rotational band also predicted from such NCCI calculations.
↳ nucl-exnucl-th0 citations
08
Fully Heavy Pentaquarks with JETHAD: A High-Energy Viewpoint
Francesco Giovanni Celiberto🇪🇸
We examine the leading-power fragmentation of fully heavy pentaquarks in high-energy hadronic collisions. To this end, we complete the release of the hadron-structure-oriented PQ5Q1.0 fragmentation functions, by discussing the $P_{5 c}$ set and delivering the $P_{5 b}$ one. These functions incorporate an improved computation of the initial-scale input for the constituent heavy-quark fragmentation channel, making them particularly suitable for describing both the direct formation of a compact multicharm state and the hadronization from a diquark-antiquark-diquark configuration. For phenomenological applications, we employ the data-validated (sym)JETHAD framework to compute and analyze NLL/NLO $^{+}$ semi-inclusive production rates of pentaquark-plus-jet systems at the upcoming HL-LHC and the future FCC. This study marks a further step toward connecting hadronic structure, precision QCD, and the emerging physics of exotic matter.
↳ hep-phhep-exhep-thnucl-ex+1Particles(2026)·6 citations
09
AI-assisted modeling and Bayesian inference of unpolarized quark transverse momentum distributions from Drell-Yan data
Zhong-Bo Kang🇺🇸 · Luke Sellers🇺🇸 · Congyue Zhang🇺🇸 · Curtis Zhou🇺🇸
We present an extraction of unpolarized quark transverse-momentum-dependent parton distribution functions (TMD PDFs) from Drell-Yan data within a Bayesian inference framework, incorporating artificial intelligence at multiple stages of the analysis. Our analysis is performed at $N^{3} LO$ in perturbative QCD combined with $N^{4} LL$ resummation accuracy. We first employ an AI-driven iterative procedure to explore and rank candidate functional forms for the nonperturbative contributions to TMD PDFs at the initial scale, as well as for the Collins-Soper evolution kernel, using $χ^{2}$ fits and physics constraints. To enable efficient Bayesian inference, we construct a surrogate model for TMD cross sections by training a machine-learning emulator over the parameter space, replacing computationally expensive repeated evaluations and allowing scalable sampling with an affine-invariant Markov Chain Monte Carlo (MCMC) ensemble. Using this framework, we perform a global analysis of Drell-Yan data from fixed-target, RHIC, and LHC experiments and extract TMD PDFs with quantified uncertainties. We compare the results with those obtained using the replica method and highlight differences in the resulting uncertainty estimates.
↳ hep-phhep-exnucl-exnucl-th5 citations

Affiliations

first authorsco-authorsvia INSPIRE