Aug 8 – 13, 2022
Hörsaalzentrum Poppelsdorf
Europe/Berlin timezone

$B\pi$ excited-state contamination in $B$-meson observables

Aug 8, 2022, 3:00 PM
CP1-HSZ/1.002 (CP1-HSZ) - HS6 (CP1-HSZ)

CP1-HSZ/1.002 (CP1-HSZ) - HS6


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Oral Presentation Weak Decays and Matrix Elements Weak Decays and Matrix Elements


Oliver Bär (Humboldt Universität zu Berlin)


Multi-particle states with additional pions are expected to result in a non-negligible excited-state contamination in lattice simulations at the physical point. We show that heavy meson chiral perturbation theory (HMChPT) can be employed to calculate the contamination due to two-particle $B\pi$ states in various $B$-meson observables like the decay constant $f_B$ and the $B^*B\pi$ coupling $g_{\pi}$. We work in the static limit and to next-to-leading order (NLO) in the chiral expansion. The $B\pi$ 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.

Primary authors

Alexander Broll (HU Berlin) Oliver Bär (Humboldt Universität zu Berlin) Rainer Sommer (DESY Zeuthen, Humboldt Berlin)

Presentation materials