Lattice Hamiltonian approach to the massless Schwinger model: Precise extraction of the mass gap
K. Cichy1,2 , A. Kujawa-Cichy 2 , M. Szyniszewski2,3
2 Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614, Poznan, Poland
3 NOWNano DTC, University of Manchester, Manchester, M13 9PL, UK
1 NIC, DESY Zeuthen, Platanenallee 6, 15738 Zeuthen, Germany
Computer Physics Communications, 1184,1666-1672 (2013)
We present results of applying the Hamiltonian approach to the massless Schwinger model. A finite basis is constructed using the strong coupling expansion to a very high order. Using exact diagonalization, the continuum limit can be reliably approached. This allows to reproduce the analytical results for the ground state energy, as well as the vector and scalar mass gaps to an outstanding precision better than 10^(−6)%.