Sea quark effects in B spectroscopy and decay constants -: art. no. 074504

We present comprehensive results for the spectrum and decay constants of hadrons containing a single b quark. The heavy quark is simulated using an O(1/M) NRQCD action and the light quark using the O(a) tadpole-improved clover action on gauge configurations containing two degenerate flavors of sea quarks at beta(n)f(=2)=5.6 provided by the HEMCGC Collaboration. We present detailed results for the lower lying S and P wave B meson states and the Lambda(b) baryon. We find broad agreement with experiment. In addition, we present results for the pseudoscalar and, for the first time, the vector decay constants fully consistent to O(alpha/M): f(B)=186(5) (stat) (19) (pert) (9) (disc) (13) (NRQCD) (+ 50)(a(-1)) MeV, f(B)* = 181(6) (stat) (18) (pert) (9) (disc) (13) (NRQCD) (+55)(a(-1)) MeV and f(Bs)/f(B) = 1.14(2) (stat) (-2)(kappa(s)). We present an investigation of sea quark effects in the B spectrum and decay constants. We compare our results with those from similar quenched simulations at beta(n)f(=0) = 6.0. For the spectrum, the quenched results reproduce the experimental spectrum well and then is no significant difference between the quenched and n(f)=2 results. For the decay constants, our results suggest that sea quark effects may be large. [S0556-2821(99)07017-4].