Exploring two nonperturbative definitions of C_{A}
Abstract
We present two determinations of the coefficient C_{A} in quenched QCD, needed to build the O( a) improved axial current. The first condition used is the requirement that the PCAC quark mass, as a function of χ_{0}, stays flat for a nontrivial spatial phase for the fermions in the Schrödinger functional. The second condition is that the PCAC relation for the groundstate and the first excited state at finite L give the same quark mass. Our results confirm previous findings that in the quenched theory the intrinsic O( a) ambiguity of C_{A} gets relevant around β ≅ 6.0.
 Publication:

Nuclear Physics B Proceedings Supplements
 Pub Date:
 March 2004
 DOI:
 10.1016/S09205632(03)026008
 arXiv:
 arXiv:heplat/0309169
 Bibcode:
 2004NuPhS.129..417D
 Keywords:

 High Energy Physics  Lattice
 EPrint:
 3 pages, Lattice2003(improve)