https://doi.org/10.1140/epjc/s10052-017-5021-4
Regular Article - Theoretical Physics
Heavy-quark form factors in the large 
limit
1
Budker Institute of Nuclear Physics, Novosibirsk, Russia
2
Institut für Theoretische Teilchenphysik, Karlsruher Institut für Technologie, Karlsruhe, Germany
3
THEP, Institut für Physik, Universität Mainz, Mainz, Germany
4
Novosibirsk State University, Novosibirsk, Russia
* e-mail: A.G.Grozin@inp.nsk.su
Received:
27
April
2017
Accepted:
23
June
2017
Published online:
7
July
2017
Heavy-quark form factors are calculated at 
to all orders in 
at the first order in 
. Using the inversion relation generalized to vertex functions, we reduce the massive on-shell Feynman integral to the HQET one. This HQET vertex integral can be expressed via a 
function; the nth term of its 
expansion is explicitly known. We confirm existing results for 
terms in the form factors (up to 
), and we present results for higher L.
© The Author(s), 2017
