HEP Lattice·hep-lat

Tue·Jul 14, 2026Tuesday·July 14, 2026

6 papers—2 primary·4 cross-listed

01
The Neutron Electric Dipole Moment from Lattice QCD using a Background Electric Field
Thomas Blum🇺🇸 · Fangcheng He🇺🇸 · Taku Izubuchi🇺🇸 · Luchang Jin🇺🇸 · Hiroshi Ohki🇯🇵 · Sergey Syritsyn🇺🇸
We present the calculation of the neutron electric dipole moment (nEDM) $d_{n}$ using 2+1 flavor domain wall fermion ensembles with fixed lattice spacing $a \approx 0.11 fm$ and pion masses of 340, 420, and 576 MeV. We show that the neutron electric dipole moment can be extracted from the energy shift induced by a static uniform external background electric field in the presence of the CP-violating QCD theta-term, $θ ˉ Q_{t o p}$ . Motivated by the Feynman-Hellmann theorem, we employ sampling of the topological charge $q_{top} (t)$ on a single time-slice rather than the global topological charge $Q_{top} = \int q_{top} (t) d t$ , which dramatically improves the statistical precision of the $θ$ -induced nEDM. Key to our method is to calculate the forward matrix element of the topological charge density in the nucleon deformed by a background electric field. We find that calculation with the traditional positive parity-projected nucleon operator is subject to large excited-state contamination. To remove the contamination, we construct the ground state of the deformed nucleon by solving a non-Hermitian generalized eigenvalue problem. With this approach, we find consistent values for the nEDM when using different nucleon interpolating operators, regardless of whether they are covariant or non-covariant under chiral transformations. Finally, after extrapolating to the physical point, we obtain $d_{n} = - 0.0050 (4)^{stat} (8)^{sys} θ ˉ$ $e$ fm, where the systematic uncertainty includes excited-state effects estimated as variation with the Euclidean-time fits and the dependence on the strength of the electric field applied to the neutron. Conventional systematic errors like discretization, finite-volume, and chiral extrapolation effects will be addressed in future work.
hep-lathep-exhep-ph3 citations
02
Chiral and $U (1)_{A}$ symmetries in background magnetic fields from lattice QCD
Heng-Tong Ding🇨🇳 · José Javier Hernández Hernández🇨🇳 · Dan Zhang🇨🇳
We study chiral symmetry and singlet $U (1)_{A}$ symmetry in QCD in a background magnetic field using lattice QCD. We first clarify the neutral-sector symmetry structure in a pure magnetic background, where the unequal electric charges of the light quarks explicitly reduce the non-singlet flavor symmetry. We identify the neutral-pion--sigma susceptibility difference, $χ_{π^{0}} - χ_{σ}$ , as the chiral-partner splitting associated with the surviving neutral non-singlet axial symmetry, and the neutral-pion--delta susceptibility difference, $χ_{π^{0}} - χ_{δ^{0}}$ , as the singlet $U (1)_{A}$ partner splitting. We also discuss the disconnected contribution to the neutral-pion susceptibility and its continuum constraint. Numerical results are obtained on fixed-scale $(2 + 1)$ -flavor HISQ ensembles with $m_{l} = m_{s}^{phys} /10$ , corresponding to a pion mass of about $220 MeV$ at vanishing magnetic field. We find that the neutral chiral-partner splitting increases with the magnetic field strength $e B$ at low temperature and decreases at sufficiently large $e B$ near the crossover, providing susceptibility-splitting counterparts of magnetic catalysis and inverse magnetic catalysis, respectively. The singlet $U (1)_{A}$ partner splitting shows an analogous low-temperature enhancement and large-field suppression near the crossover, with the suppression setting in at larger $e B$ and remaining milder than in the chiral channel. These results provide a first lattice-QCD study of neutral-sector probes of chiral and singlet $U (1)_{A}$ partner susceptibility splittings in background magnetic fields.
hep-lathep-phhep-thnucl-th0 citations
03
Hardware-efficient quantum simulation of intense-field QED
Zhuoyi Li🇨🇳 · Bin Xu🇨🇳 · Zhongtian Dong🇺🇸 · Yuxiang Huang🇨🇳 · Ying-Ying Li🇨🇳 · Yiheng Lin🇨🇳 · Jing Shu🇨🇳
Strong electromagnetic backgrounds make quantum electrodynamics a real-time nonperturbative problem involving dressed fermions and dynamical photons. We propose a trapped-ion protocol for simulating intense-field QED in $3 + 1$ dimensions in the Furry picture. The construction encodes photon modes in collective phonons and Volkov-dressed fermion modes in ion spins, combining native spin-phonon couplings with Clifford circuits that compress nonlocal Jordan--Wigner strings. For nonlinear Breit--Wheeler pair production, the protocol has polynomial resource scaling and is benchmarked against exact single-mode dynamics with controlled Trotter errors. With experimentally motivated phonon heating and dephasing, zero-noise extrapolation substantially reduces deviations in photon-survival and pair-production signals. These results provide a hardware-efficient route to intense-field particle-production dynamics beyond perturbative or static-field descriptions.
↳ quant-phhep-lathep-ph0 citations
04
Bosonization versus the Nielsen-Ninomiya theorem
Saif Ullah Baig🇺🇸 · Shi Chen🇺🇸 · Aleksey Cherman🇺🇸 · Maria Neuzil🇺🇸
Thanks to bosonization, bosonic lattice models can offer a lattice regularization of chiral fermions. We construct chiral lattice fermion operators in the 2D modified Villain scalar model and evaluate their correlation functions. This microscopic bosonic model has an ultra-local action and an ultra-local symmetry that realizes the fermionic chiral symmetry under bosonization. The reconstructed lattice Dirac operator has no doublers, but is consistent with the Nielsen-Ninomiya theorem because it turns out to be non-local. The non-locality of this derived quantity at finite lattice spacing does not pose any obstructions to gauging the non-anomalous symmetries of the model, which is itself ultra-local.
↳ hep-thcond-mat.str-elhep-lat2 citations
05
Multipole structure of the $N \to Δ$ Transition Generalized Parton Distributions
June-Young Kim🇰🇷 · Hyun-Chul Kim🇰🇷
We establish the multipole structure of the $N \to Δ$ transition at the level of the generalized parton distributions (GPDs). We decompose the four transition GPDs into one monopole, two dipole, and one quadrupole components in the transverse plane by a multipole expansion of the covariant transition matrix element in terms of the three-dimensional spin-transition tensors and the transverse momentum transfer. These multipole components are in one-to-one correspondence with the light-front helicity amplitudes. In the zero-skewness limit, the multipole GPDs define impact-parameter transition densities, which generalize the transverse transition charge densities to the $x$ -dependent level. These transition densities arise from non-diagonal matrix elements between two distinct hadronic states and must therefore be distinguished from the diagonal densities of the nucleon and the $Δ$ . The multipole transition densities visualize the monopole, dipole, and quadrupole structures of the partonic $N \to Δ$ transition in the transverse plane.
↳ hep-phhep-exhep-lat1 citation
06
$p$ -Form Gauge Dynamics and Digital Quantum Simulation -- Flux and Cosmological Constant Neutralization
Soo-Jong Rey🇰🇷
I develop a Hamiltonian framework for $Z_{k}$ $p$ -form gauge fields on arbitrary oriented cell complexes in arbitrary dimensions. Gauge qudits are defined by $p$ -cells, charged boundary qudits by $(p - 1)$ -cells, Gauss-law generators by boundary map $\partial_{p}$ , and magnetic checks by $\partial_{p + 1}$ . The same cellular structure produces local dressed Wilson operators, and at $k = 2$ a Calderbank-Shor-Steane check complex relevant to quantum error correction. I then specialize to $p = 2, k = 2$ , where the magnetic 3-cell term is absent and the one-form Gauss-law can be solved exactly. The physical Hilbert space is parameterized by plaquette electric-flux variables, while the link configuration is reconstructed as the dynamical boundary of the evolving flux domains. The reduced Hamiltonian is an Ising-type plaquette model, where its local transverse-field term is the physical image of the boundary-dressed Wilson operator $σ_{p}^{z} \prod_{ℓ \in \partial p} τ_{ℓ}^{z}$ . A tube-cap quench compares two initial flux fillings with the same initial boundary loops. Exact diagonalization on $4 \times 4$ , $6 \times 4$ , and $5 \times 5$ tori finds that the cap loses $20$ - $37%$ of its occupied-flux area, while the tube remains nearly pinned. A finite-size scaling locates a dynamical crossover of tension-to-density ratio near $(m / ε_{E})_{c} ≃ 1.89$ . The unreduced plaquette-plus-link encoding provides local Gauss-law checks and a direct digital implementation, while the reduced plaquette-only Hamiltonian supplies the exact benchmark. The result places the specific top-form discharge and the cosmological constant neutralization calculation inside a general higher-form Hamiltonian and coding framework.
↳ quant-phcs.IThep-lathep-th+10 citations

Affiliations

first authorsco-authorsvia INSPIRE

The Neutron Electric Dipole Moment from Lattice QCD using a Background Electric Field

Chiral and U(1)A​ symmetries in background magnetic fields from lattice QCD

Hardware-efficient quantum simulation of intense-field QED

Bosonization versus the Nielsen-Ninomiya theorem

Multipole structure of the N→Δ Transition Generalized Parton Distributions

p-Form Gauge Dynamics and Digital Quantum Simulation -- Flux and Cosmological Constant Neutralization

Affiliations

Chiral and $U (1)_{A}$ symmetries in background magnetic fields from lattice QCD

Multipole structure of the $N \to Δ$ Transition Generalized Parton Distributions

$p$ -Form Gauge Dynamics and Digital Quantum Simulation -- Flux and Cosmological Constant Neutralization