Exploring the invisible renormalon: Renormalization of the heavyquark kinetic energy
Abstract
Using the virial theorem of the heavyquark effective theory, we show that the mixing of the operator for the heavyquark kinetic energy with the identity operator is forbidden at the oneloop order by Lorentz invariance. This explains why such a mixing was not observed in several oneloop calculations using regularization schemes with a Lorentzinvariant UV regulator, and why no UV renormalon singularity was found in the matrix elements of the kinetic operator in the bubble approximation (the ``invisible renormalon''). On the other hand, we show that the mixing is not protected in general by any symmetry, and it indeed occurs at the twoloop order. This implies that the parameter λ^{H}_{1} of the heavyquark effective theory is not directly a physical quantity, but requires a nonperturbative subtraction.
 Publication:

Physics Letters B
 Pub Date:
 February 1997
 DOI:
 10.1016/S03702693(96)016000
 arXiv:
 arXiv:hepph/9610471
 Bibcode:
 1997PhLB..393..110N
 Keywords:

 High Energy Physics  Phenomenology
 EPrint:
 13 pages, 3 figures