English

Matching the HQET to Coulomb Type Bound States

High Energy Physics - Phenomenology 2009-09-25 v1

Abstract

We show that the infinite imaginary anomalous dimensions of certain heavy quark-antiquark currents in the HQET arise due to an inappropriate commutation of two limits, namely coinciding velocities and infinite cut-off. This commutation is not apparent when dimensional regularization is used, but it can be made manifest in a cut-off regularization. We argue that operators containing heavy quark and antiquark fields with the same velocity in the HQET must not be matched to perturbative QCD but to Coulomb-type bound state contributions. We show how to do so at one loop level.

Keywords

Cite

@article{arxiv.hep-ph/9505442,
  title  = {Matching the HQET to Coulomb Type Bound States},
  author = {A. Pineda and J. Soto},
  journal= {arXiv preprint arXiv:hep-ph/9505442},
  year   = {2009}
}

Comments

15 pages, tex, 4 figures avaliable upon request