DOI 10.1007/s100529800734
Couplings of heavy hadrons with soft pions from QCD sum rules
1 Institut für Physik, Johannes-Gutenberg-Universität,
Staudinger Weg 7, D-55099 Mainz, Germany
2 Institut für Theoretische Physik II,
Bayrische-Maximilians-Universität,
Am Hubland, D-97074 Würzburg, Germany
Received: 19 June 1997 / Published online: 20 February 1998
Abstract
We estimate the couplings in the Heavy Hadron Chiral Theory (HHCT) lagrangian
from the QCD sum rules in an external axial field.
We take into account the perturbative correction to the meson correlator
in the infinite mass limit.
With the perturbative correction and three successive power corrections,
the meson correlator in an axial field
becomes one of the best known correlators.
In spite of this, the corresponding sum rule is not very stable.
It yields the result ,where is the central value
of the heavy meson decay constant with the perturbative correction [14].
This result is surprisingly low as compared with the constituent quark
model estimate g1=0.75.
The sum rules for g2,3 following from nondiagonal
and diagonal baryon correlators in
an external axial field suggest
,while diagonal
and nondiagonal baryon sum rules
have too large uncertainties.
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