$$B\pi $$ B π excited-state contamination in lattice calculations of B-meson correlation functions

Autor: Oliver Bär, Alexander Broll, Rainer Sommer
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: European Physical Journal C: Particles and Fields, Vol 83, Iss 8, Pp 1-22 (2023)
Druh dokumentu: article
ISSN: 1434-6052
DOI: 10.1140/epjc/s10052-023-11906-z
Popis: Abstract Multi-particle states with additional pions are expected to result in a difficult-to-control excited-state contamination in lattice simulations. We show that heavy meson chiral perturbation theory can be employed to estimate the contamination due to two-particle $$B\pi $$ B π states in various B-meson observables, like the B-meson decay constant and the $$B^*B\pi $$ B ∗ B π coupling. We work in the static limit and to next-to-leading order in the chiral expansion, i.e. including $$\textrm{O}(p).$$ O ( p ) . The $$B\pi $$ B π states are found to typically lead to an overestimation of the observables at the few percent level. We determine two of the LECs from $$B\rightarrow \pi $$ B → π form factor computations of the KEK group (Colquhoun et al. in Phys. Rev. D 106:054502, 2022) and discuss ways to determine the others. In particular, one LEC which is associated with smeared interpolating fields seems to be easily accessible and thus opens up a way to systematically study the effect of smearing on excited-state effects.
Databáze: Directory of Open Access Journals
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