Towards the Mass Shift and Discrete Chiral Symmetry in the Lattice QED Hamiltonian

by Shoto Aoki (RIKEN)

Wednesday 14 Oct 2026, 14:00 → 15:00 Asia/Shanghai

B105 (CHEP)

We study the lattice Hamiltonian formulation of quantum electrodynamics with staggered fermions and extend the mass-shift construction developed for the Schwinger model to the $3+1$-dimensional case. In the Schwinger model, the chiral transformation is realized as a one-site translation of the staggered fermion field. By introducing a correction term, referred to as the mass shift, the lattice Hamiltonian possesses an exact discrete chiral symmetry, while also allowing for the correct transformation of the $\theta$ parameter, leading to significantly improved convergence of numerical calculations.

In this work, we generalize this construction to $3+1$-dimensions and show that the resulting lattice Hamiltonian with the mass shift also possesses an exact discrete chiral symmetry. The realization of the $\theta$ parameter shift is left for future work.

Bio:
Shoto Aoki is a postdoctoral researcher at the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) in Japan. He is currently a visiting scholar at the University of California, Berkeley (UC Berkeley), where he works on theoretical aspects of lattice gauge theory. His current research focuses on lattice Maxwell theory in the Villain formulation, as well as chiral symmetry and mass shifts in the Hamiltonian formalism.

He received his PhD from Osaka University in 2024 under the supervision of Hidenori Fukaya. During his PhD, he studied fermion systems with curved domain walls and investigated how the edge modes respond to gravitational potentials.