Quenched Hadrons using Wilson and O(a)-Improved Fermion Actions at   beta=6.2
  We present the first study of the light hadron spectrum and decay constants for quenched QCD using an O(a)-improved nearest-neighbour Wilson fermion action at \beta=6.2. We compare the results with those obtained using the standard Wilson fermion action, on the same set of 18 gauge field configurations of a 24^3 times 48 lattice. For pseudoscalar meson masses in the range 330-800 MeV, we find no significant difference between the results for the two actions. The scales obtained from the string tension and mesonic sector are consistent, but differ from that derived from baryon masses. The ratio of the pseudoscalar decay constant to the vector meson mass is roughly independent of quark mass as observed experimentally, and in approximate agreement with the measured value. 
The UKQCD Collaboration: C.R. Allton, H. Duong, C.T. Sachrajda, R.M.   Baxter, S.P. Booth, K.C. Bowler, S. Collins, D.S. Hen...