Determining gA using non-perturbatively O(a) improved Wilson fermions
نویسنده
چکیده
On the lattice, for Wilson fermions, the chiral Ward Identity is only approximately true, due to discretisation effects. We have a finite renormalisation constant ZA(g) to determine by demanding that a Ward Identity is obeyed to O(a) (with n = 2 for O(a) improved fermions). The ALPHA collaboration [1] has found ZA for quenched fermions using the Schrödinger functional and PCAC; here, alternatively, we shall use the chiral Ward identity for the propagator. We shall first check our ZA results for quenched fermions before then determining ZA for unquenched fermions. The chiral Ward identity for the propagator, SR, reads γ5S −1 R + S −1 R γ5 = 2 mR Λ P R,
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