An extended two-hadron operator is developed to extract the spectra of irreducible representations (irreps) in the finite volume. The irreps of the group for the finite volume system are projected using a coordinate-space operator. The correlation function of this operator is computationally efficient to extract lattice spectra of the specific irrep. In particular, this new formulation only requires propagators to be computed from two distinct source locations, at fixed spatial separation. We perform a proof-of-principle study on a 243×48 lattice volume with mπ≈900 MeV by isolating various spectra of the ππ system with isospin-2 including a range of total momenta and irreps. By applying the L\"uscher formalism, the phase shifts of S-, D- and G-wave ππ scattering with isospin-2 are extracted from the spectra.
@article{arxiv.2109.01557,
title = {Towards high partial waves in lattice QCD with a dumbbell-like operator},
author = {Jia-Jun Wu and Waseem Kamleh and Derek B. Leinweber and Yan Li and Gerrit Schierholz and Ross D. Young and James M. Zanotti},
journal= {arXiv preprint arXiv:2109.01557},
year = {2022}
}