Hard Pion Chiral Perturbation Theory for $B\to \pi$ and $D\to \pi$ Formfactors

Abstract

We use one-loop Heavy Meson Chiral Perturbation Theory (HMCHPT) as well as a relativistic formulation to calculate the chiral logarithms $m_{\pi }^2\log \left(m_{\pi }^2/{\mu }^2\right)$ contributing to the formfactors of the semileptonic $B\to \pi$ decays at momentum transfer $q^2$ away from $q_{\max }^2=(m_B-m_{\pi }{)}^2$. 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.

16 pages, two wrong statements about relation relativistic-heavy meson formfactors changed and (a lot of) misprints corrected. These include misprints in the main results

References in corpus (3)

• Light-cone sum rules for $B\to \pi$ form factors revisited
• SU(2) chiral perturbation theory for Kl3 decay amplitudes
• $K\to \pi \pi$ Decays in SU(2) Chiral Perturbation Theory

Cited by in corpus (6)

• $B\to \pi \ell \nu$ and $B_s\to K\ell \nu$ form factors and $|V_{ub}|$ from 2+1-flavor lattice QCD with domain-wall light quarks and relativistic heavy quarks
• $B_s\to K\ell \nu$ form factors from lattice QCD
• Vector Formfactors in Hard Pion Chiral Perturbation Theory
• On the factorization of chiral logarithms in the pion form factors
• Testing the Standard Model under the weight of heavy flavors
• Phenomenology from the Lattice