Precision ${\rm Y}$ Spectroscopy and Fundamental Parameters From NRQCD

Abstract

We present results from a high precision NRQCD simulation of the quenched ${\rm Y}$ system at $\beta =6$. We demonstrate a variety of important lattice techniques, including the perturbative improvement of actions, tadpole improvement, and multicorrelated fits for extracting the spectrum of excited states. We present new determinations of ${\alpha }_s(M_Z)$ and $M_b$, two fundamental parameters of the Standard Model.

Comments: 8 pages