Power scaling rules for charmonia production and HQEFT
We discuss the power scaling rules along the lines of a complete Heavy Quark Effective Field Theory (HQEFT) for the description of heavy quarkonium production through a color-octet mechanism. To this end, we firstly derive a tree-level heavy quark effective Lagrangian keeping both particle-antiparticle mixed sectors allowing for heavy quark-antiquark pair annihilation and creation, but describing only low-energy modes around the heavy quark mass. Then we show the consistency of using HQEFT fields in constructing four-fermion local operators a la NRQCD, to be identified with standard color-octet matrix elements. We analyze some numerical values extracted from charmonia production by different authors and their hierarchy in the light of HQEFT.