HEP Lattice·hep-lat

Fri·Sep 4, 2026Friday·September 4, 2026

5 papers—4 primary·1 cross-listed

01
Real-Time String Dynamics in $3 + 1$ D Lattice Quantum Electrodynamics
Helen Zwölfer🇩🇪 · Giovanni Cataldi🇩🇪 · Umberto Borla🇩🇪 · Jad C. Halimeh🇩🇪
Understanding real-time string dynamics in three spatial dimensions is essential for connecting quantum simulations of lattice gauge theories (LGTs) to the physical dimensionality of QED and QCD, where transverse fluctuations and competing local processes proliferate. We present the first real-time simulations of string breaking in $3 + 1$ D lattice quantum electrodynamics. Using tree tensor networks, we simulate the quench dynamics of electric flux strings in a $3 + 1$ D U(1) LGT with dynamical matter. At strong coupling, the string breaks resonantly at a sharp resonance condition of mass and gauge couplings, converting electric energy into matter--antimatter pairs that screen the static charges. Off resonance, we classify all competing channels---pair production, string deformations and extensions, and flux loops---whose multiplicity, extensive for pair production and flux loops, depletes the string sector even far from resonance. A channel-resolved perturbation theory quantitatively reproduces these dynamics and their Fourier spectrum. Our results establish diagnostics and benchmarks for upcoming quantum simulators of higher-dimensional LGTs.
hep-latcond-mat.quant-gashep-phhep-th+10 citations
02
Non-Abelian string melting and thermalization in an open lattice gauge theory
Erick Parra Verde🇩🇪 · Giovanni Cataldi🇩🇪 · Stefan Kühn🇩🇪 · Giuseppe Magnifico🇮🇹 · Jad C. Halimeh🇩🇪
Open-system lattice gauge theory (LGT) has so far been developed predominantly in Abelian settings, leaving open how genuinely non-Abelian gauge structure reshapes dissipative real-time dynamics. Here, we study a $1 + 1$ D SU(2) Yang--Mills LGT with dynamical matter coupled to a thermal scalar environment through a gauge-preserving Lindblad evolution, which we solve using tensor networks. Starting from a quark--antiquark pair connected by a chromoelectric flux string, we find that the thermal medium melts the string by delocalizing the color charges and screening the flux; on resonance, this dissipative melting competes with and delays coherent string breaking. The thermalization time is non-monotonic in the environment coupling, decreasing through environment-assisted transport at weak dissipation before increasing in a quantum-Zeno regime. In the strong-dephasing limit, a Schrieffer--Wolff expansion maps the dynamics to a classical exclusion process and yields the Liouvillian thermalization time analytically. Beyond these generic open-system effects, the non-Abelian matter structure produces a systematic mesonic bias in the steady state, while the thermalization time decreases with temperature, in contrast to the Abelian Schwinger model trend and in qualitative agreement with pNRQCD studies of the quark--gluon plasma. These results establish a gauge-preserving framework for thermalization and string dynamics in open non-Abelian lattice gauge theories.
hep-latcond-mat.quant-gascond-mat.stat-mechhep-ph+10 citations
03
Lattice QCD calculation of the pion-nucleon coupling $g ˉ_{0}$ induced by the QCD $Θ$ -term
Fangcheng He🇺🇸 · Tanmoy Bhattacharya🇺🇸 · Rajan Gupta🇺🇸 · Emanuele Mereghetti🇺🇸
We present lattice QCD results for the CP violating pion-nucleon coupling $g ˉ_{0}$ induced by the QCD $Θ$ term from the analysis of three 2+1+1-flavor ensembles generated with highly improved staggered quarks (HISQ) by the MILC collaboration. These ensembles are at lattice spacing $a \approx 0.09 fm$ and pion masses of 313, 226 and 138 MeV, respectively. The coupling $g ˉ_{0}$ is extracted in two ways. First, from the matrix element of the correlation between the pesudoscalar current and the topological charge evaluated between the nucleon ground state. The data for correlation functions with both the pseudoscalar and axial vector exhibit large contamination from the $N π$ excited state. We show that these can be controlled at the leading order using chiral perturbation theory ( $χ$ PT) and the axial Ward identity (AWI, also called the partially conserved axial current (PCAC) relation). The result after removing the $N π$ contamination and extrapolating to the physical pion mass is, however, noisy: $g ˉ_{0} / (2 F_{π}) = - 7 (63) \times 1 0^{- 3} Θ$ . The more precise result $g ˉ_{0} / (2 F_{π}) = 17.4 (1.9) \times 1 0^{- 3} Θ$ is obtained using low energy effective field theory methods or equivalently the AWI. Since contamination from the $N π$ excited states arises in the calculation of many nucleon matrix elements, we give an extended discussion on them and the use of the AWI for controlling them in the calculation of $g ˉ_{0}$ .
hep-lathep-ph0 citations
04
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
05
Center-twisted Gribov spectra and the finite-volume Gaussian response in the refined Gribov--Zwanziger framework
Okuto Morikawa🇯🇵
We develop a continuum framework for comparing the Gribov--Zwanziger and center-vortex descriptions of confinement through the gauge-invariant twisted partition function of the electric $Z_{N}^{[1]}$ 1-form symmetry. A background 2-form field $B$ , equivalently an 't~Hooft twist on a torus, labels a global sector and is not itself a dynamical center vortex. For a minimal irreducible twist on $T^{4}$ , we derive the complete adjoint momentum lattice of $S U (N)$ . The twisted spectrum is exactly the scalar spectrum on an enlarged torus with periods $(L_{1}, L_{2}, N L_{3}, N L_{4})$ with the ordinary-torus sublattice removed. This yields a finite Faddeev--Popov gap at the flat representative and reduces twisted-minus-untwisted spectral traces to ordinary torus traces. For the refined Gribov--Zwanziger (RGZ) kernel, Poisson resummation gives an exact finite-volume Bessel-function winding sum with a universal center-twist projector. We evaluate the Gaussian one-loop integral at fixed RGZ parameters up to the finite-dimensional global zero-mode/stabilizer normalization. The Zwanziger determinants cancel, while the gauge-fixing/ghost sector leaves a universal massless primed determinant on $T^{4}$ ; the untwisted sector also contains constant gluon modes. The only normalization not fixed by the local quadratic Hessian is the relative zero-mode/stabilizer measure of the reducible untwisted and irreducibly twisted flat connections. We also derive closed finite-volume sources for the RGZ stationary equations. The massive response is exponentially suppressed at large volume, whereas the massless factor depends on the global zero-mode normalization. Thus the Gaussian calculation does not by itself establish the strong center-vortex-condensation criterion for $Z [B] / Z [0]$ , but it isolates the remaining global normalization problem and separates a global twist from an actual dynamical vortex.
↳ hep-thhep-lat0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Real-Time String Dynamics in 3+1D Lattice Quantum Electrodynamics

Non-Abelian string melting and thermalization in an open lattice gauge theory

Lattice QCD calculation of the pion-nucleon coupling gˉ​0​ induced by the QCD Θ-term

First Two-Hadron Form Factor from QCD

Center-twisted Gribov spectra and the finite-volume Gaussian response in the refined Gribov--Zwanziger framework

Affiliations

Real-Time String Dynamics in $3 + 1$ D Lattice Quantum Electrodynamics

Lattice QCD calculation of the pion-nucleon coupling $g ˉ_{0}$ induced by the QCD $Θ$ -term