
Johan Bijnens, Ilaria Jemos
Hard Pion Chiral Perturbation Theory for $B\to\pi$ and $D\to\pi$
Formfactors
Abstract
We use oneloop Heavy Meson Chiral Perturbation Theory (HMCHPT) as well as
a relativistic formulation to calculate the chiral logarithms
$m^2_\pi\log{\left(m^2_\pi/\mu^2\right)}$ contributing to the formfactors
of the semileptonic $B\rightarrow \pi$ decays at momentum transfer $q^2$
away from $q^2_\mathrm{max}=(m_Bm_\pi)^2$. We give arguments why this
chiral behavior is reliable even in the energy regime with hard or fast
pions. These results can be used to extrapolate the formfactors calculated
on the lattice to lower light meson masses.
LU TP 1016
