The Top Quark: Experimental Roots and Branches of Theory

The CDF and D0 experiments at the Fermilab Tevatron have discovered the top quark and provided first measurements of many of its properties. The small top sample gathered by Run I leaves open many possibilities for top physics beyond the standard model. Run II and the LHC (and eventually an LC) promise to deepen our knowledge of the top quark and its relationship to electroweak symmetry breaking.Comment: 14 pages, 9 figures; talk presented at HCP200

Thinking About Top: Looking Outside The Standard Model

The top quark is by far the heaviest known fermion [1]. In consequence, experiment is just beginning to explore its properties, and some of them may yet prove to be distinctly non-standard. The very size of the top quark's mass even hints at the possibility of a special role for top in electroweak symmetry breaking. This talk examines the top quark in the context of physics beyond the standard model, and discusses how Run II can help elucidate the true nature of top.Comment: 14 pages, 13 figures, talk presented at the Thinkshop on Top Quark Physics at Run II, 16-18 October, 1998, Fermila

Strongly-Interacting Heavy Flavors Beyond the Standard Model

The origin of mass must lie in physics beyond the Standard Model. Dynamical electroweak symmetry breaking models like technicolor can generate masses for the W and Z bosons. Providing the large top quark mass and large top-bottom mass splitting while keeping rho parameter and flavor-changing neutral currents small requires new strong dynamics for the top and bottom quarks. In consequence, new particles are predicted at scales up to 10 TeV with signatures in jets or heavy flavors. Searches for these states are underway at Fermilab and LEP II.Comment: 6 pages, 3 figures, talk given at QCD Moriond (3-20-2000

Top Theories

As the most recently discovered and heaviest quark, the top presents us with theoretical challenges. How are we to understand its properties within the larger effort to explain the origins of electroweak and flavor symmetry breaking ? This talk discusses some of the surprises the top quark may have in store for us and indicates how experiment may help us pinpoint the truth about top.Comment: 17 pages, 15 figures, Talk presented at Heavy Flavours 8, University of Southampton, England, July 25-29, 199

Technicolor Evolution

This talk describes how modern theories of dynamical electroweak symmetry breaking have evolved from the original minimal QCD-like technicolor model in response to three key challenges: R_b, flavor-changing neutral currents, and weak isospin violation.Comment: 9 pages, 10 figures, RevTeX4.0. Talk given at Snowmass 2001; typo corrected, references added; reference adde

General solution of an exact correlation function factorization in conformal field theory

We discuss a correlation function factorization, which relates a three-point function to the square root of three two-point functions. This factorization is known to hold for certain scaling operators at the two-dimensional percolation point and in a few other cases. The correlation functions are evaluated in the upper half-plane (or any conformally equivalent region) with operators at two arbitrary points on the real axis, and a third arbitrary point on either the real axis or in the interior. This type of result is of interest because it is both exact and universal, relates higher-order correlation functions to lower-order ones, and has a simple interpretation in terms of cluster or loop probabilities in several statistical models. This motivated us to use the techniques of conformal field theory to determine the general conditions for its validity. Here, we discover a correlation function which factorizes in this way for any central charge c, generalizing previous results. In particular, the factorization holds for either FK (Fortuin-Kasteleyn) or spin clusters in the Q-state Potts models; it also applies to either the dense or dilute phases of the O(n) loop models. Further, only one other non-trivial set of highest-weight operators (in an irreducible Verma module) factorizes in this way. In this case the operators have negative dimension (for c < 1) and do not seem to have a physical realization.Comment: 7 pages, 1 figure, v2 minor revision

Looking for new gluon physics at the Tevatron

The impact of nonrenormalizable gluon operators upon inclusive jet cross sections is studied. Such operators could arise in an effective strong interaction Lagrangian from gluon substructure and would induce observable cross section deviations from pure QCD at high transverse jet energies. Comparison of the theoretical predictions with recent CDF data yields a lower limit on the gluon compositeness scale $\Lambda$. We find \Lambda > 2.03 \TeV at $95\%$~CL

The Hunting of the MR Model

We consider experimental signatures of the standard model's minimal supersymmetric extension with a continuous $U(1)_R$ symmetry (MR model). We focus on the ability of existing and planned electron-positron colliders to probe this model and to distinguish it from both the standard model and the standard model's minimal supersymmetric extension with a discrete $R$-parity.Comment: TeX (uses harvmac). 18 pages. Revision: added text and figure about effects of b-jet tagging at LEP II. 7 figures available on request. CTP \# 2190. HUTP-92/A05