why does dimensional regularization need counterterms ?? if all the integrals in 'dimensional regularization' are FINITE why do we need counterterms ?? in fact all the poles of the Gamma function are simple hence the only divergent quantity is the limit as d tends to 4 of [tex] 1/(d-4) [/tex] which is ONLY a divergent quantity that could be 'absobed' or re-parametered as a divergent universal constant 'a'