10884562
Creutz ratios from color-truncated lattice configurations.
We investigate whether information about Creutz ratios is encoded, separately, in each gluon color component of numerically generated lattice configurations. Working in SU(2) lattice gauge theory in the Landau gauge, we set two of the three gluon color components to zero, and compensate for the loss of two-thirds of the fluctuation by simply rescaling the remaining component by a factor of {radical}3 . Creutz ratios are then computed with this ``Abelianized`` configuration. We find that the Creutz ratios of loops constructed from Abelianized links converge to the usual Creutz ratios in the scaling regime.
116832182
Excited State Effective Masses
The effective mass description of Euclidean time hadron correlation functions is extended to incorporate multiple excited states and multiple correlation functions. In general, the effective masses will be determined by finding the roots of some polynomial.
6851820
The Effect of Reduced Spatial Symmetries on Lattice States: Results for Non-zero Linear Momentum
The irreducible representations of the cubic space group are described and used to determine the mapping of continuum states to lattice states with non-zero linear momentum. The Clebsch-Gordan decomposition is calculated from the character table for the cubic space group. These results are used to identify multiparticle states which appear in the hadron spectrum on the lattice.
117040988
Lattice QCD determination of states with spin 5/2 or higher in the spectrum of nucleons
Energies for excited isospin 1/2 states that include the nucleon are computed using quenched, anisotropic lattices. Baryon interpolating field operators that are used include nonlocal operators that provide G{sub 2} irreducible representations of the octahedral group. States with spin 5/2 or higher are identified as degenerate energies that occur in irreducible representations of the octahedral group corresponding to the subduction of the continuum spin.
8077181
The Conformal Window in SU(3) Yang-Mills
Yang-Mills theory is known to exhibit very different behavior as the number of light fermion flavors N f is varied. In particular, for sufficiently large N f the theory changes fro confining to conformal behavior in the infrared. We have obtained results for SU(3) Yang-Mills, based on the study of the running coupling through the Schrodinger Functional approach, that the transition between these two phases occurs between 8 and 12 flavors. I will present the details of our staggered fermion simulations at N f = 8 and 12.
118545140
From Lattice Strong Dynamics to Phenomenology
We present updated results on the chiral properties of SU(3) gauge theories with 2 and 6 massless Dirac fermions in the fundamental representation. Our focus is on the ratio $\langle \bar{\psi} \psi \rangle / F^3$, where $\langle \bar{\psi} \psi \rangle$ is the chiral condensate and $F$ is the pseudo-Nambu-Goldstone-boson decay constant. This ratio is of interest in the context of fermion mass generation within composite Higgs theories. By re-expanding certain ratios using next-to-leading-order chiral perturbation theory, we confirm our previous result of significant enhancement of this ratio at $N_f = 6$ over $N_f = 2$.
15582447
Electromagnetic production of quarkonium in Z0 decay.
The decay [ital Z][sup 0][r arrow][ital Q]+[ital l][sup +][ital l[minus]], where [ital Q] is a [ital J][sup [ital P][ital C]]=1[sup [minus][minus]] quarkonium state, has a very clean final state which should make it easy to detect. The branching ratio of this mode is greater than 10[sup [minus]6] for [rho], [phi], and [psi], indicating that these processes may be detectable at CERN LEP.