2022/10/13 by Bar, Oliver, Broll, Alexander, Sommer, Rainer
#FOS: Physical sciences #High Energy Physics - Lattice (hep-lat)
paper · doi:10.48550/arxiv.2210.06857
Multi-particle states with additional pions are expected to result in a non-negligible excited-state contamination in lattice simulations. We show that heavy meson chiral perturbation theory can be employed to calculate the contamination due to two-particle Bπ states in various B-meson observables like the B-meson decay constant and the BB^*π coupling. We work in the static limit and to next-to-leading order in the chiral expansion. The Bπ states are found to typically overestimate the observables at the few percent level depending on the size of two currently unknown NLO low-energy coefficients. A strategy to independently measure one of them with the 3-point function of the light axial vector current will be discussed.