Electroweak Symmetry Breaking and Physics beyond the Standard Model

In order to extend the Standard Model to TeV scale energies one must address two basic questions: (1) What is the complete description of the effective theory of fundamental particles at and below the electroweak scale? and (2) What is the dynamics responsible for electroweak symmetry breaking? The answers to these questions are crucial for addressing the third outstanding question of particle physics: What are the origins of the Standard Model parameters? We briefly summarize current theoretical approaches to answering these questions. To be published in Electroweak Symmetry Breaking and New Physics at the TeV Scale, edited by T.L. Barklow, S. Dawson, H.E. Haber, and J.L. Siegrist. This manuscript has been authored under contract number DE-AC02-76CH00016 with the U.S. Department of Energy. Accordingly, the U.S. Government retains a non-exclusive, royaltyfree license to publish or reproduce the published form of this contribution, or to allow others to do so, for U.S. Government purposes. ELECTROWEAK SYMMETRY BREAKING AND PHYSICS BEYOND THE STANDARD MODEL