Static potential in the SU(2) Higgs model

We present results for the static potential in the confinement phase of the SU(2) Higgs model on the lattice. Introducing a suitable matrix correlation function we observe string breaking at a distance r_b ~ 1.8 r_0, where the length scale r_0 has a value r_0 ~ 0.5 fm in QCD. The method presented here may lead the way towards a treatment of string breaking in QCD.Comment: LATTICE98(confine), 3 pages, 3 figure

Measuring Hidden Higgs and Strongly-Interacting Higgs Scenarios

Higgs couplings can be affected by physics beyond the Standard Model. We study modifications through interactions with a hidden sector and in specific composite Higgs models accessible at the LHC. Both scenarios give rise to congruent patterns of universal, or partially universal, shifts. In addition, Higgs decays to the hidden sector may lead to invisible decay modes which we also exploit. Experimental bounds on such potential modifications will measure the concordance of an observed Higgs boson with the Standard Model.Comment: 12 pages, 7 figures; version to be published in Phys. Lett.

Review on String Breaking - the Query in Quest of the Evidence

Considerable progress has been achieved recently in the observation of string breaking within non-Abelian Higgs models, by use of multi-channel methods allowing for broken string states. Similarly, in pure gauge theory this approach has been shown to reveal string breaking for color charges in the adjoint represaentation. For QCD with dynmical fermions, one needs substantial progress in noise reduction, however, to render such techniques viable.Comment: June 1999, 6 pages, 11 figures. Plenary talk presented at the 17th Int. Symposium on Lattice Field Theory (Lattice 99), Pisa, Italy 29 Jun - 3 Jul, 199