Heavy quark form factors in the large ${\beta }_0$ limit

Abstract

Heavy quark form factors are calculated at ${\beta }_0{\alpha }_s\sim 1$ to all orders in ${\alpha }_s$ at the first order in $1/{\beta }_0$. The $n_f^2{\alpha }_s^3$ terms in the recent results [arXiv:1611.07535] for the vector form factors are confirmed, and $n_f^{L-1}{\alpha }_s^L$ terms for higher $L$ are predicted.

Comments: v2: the section on inversion relations extended; v3: 3 refs added, discussion of the hypergeometric function expansion extended; v4: eq. (22) and fig. 5 corrected