LHC Olympics Workshop and String Phenomenology 2006 Conference, August 7 - December 15, 2006

This is the final report of the organizers of the String Phenomenolgy program of which the LHC Olympics and the String Phenomenolgy conference were a part. In addition, it includes the list of talks from our website which comprise the online proceedings. These talks constitute the proceedings of these meetings. Particle physics is at the dawn of a new era, as the Large Hadron Collider, the most powerful accelerator ever built, is set to begin operation at the end of 2007. This instrument will probe distances fully an order of magnitude smaller than probed in the past. It is widely expected that dramatic effects, associated with the breaking of the symmetry of the electroweak interactions, will appear at this scale. Candidate phenomena include supersymmetry, new strong interactions, and large or warped extra dimensions; another possibility is simply the Standard model itself (including the Higgs particle). Similarly, the last decade has seen great leaps in our knowledge of the early history of the universe. Inflation as the origin of cosmic structure is now reasonably well established. Until recently, superstring theory, despite its successes in taming the difficulties of quantum gravity, has proven unable to make definitive predictions for phenomena at accelerators or in the cosmos. Recent developments have raised hopes that this situation is about to change. Previously, one could identify at least three related, major obstacles to any detailed understanding of how string theory was related to nature. (1) There is a vast array of possible string ground states, distinguished, for example, by various topological features. (2) Only those ground states with a unbroken supersymmetry were at all understood quantum mechanically. (3) Among candidate non-supersymmetric states, there were always (pseudo)moduli (scalar fields with potentials which at least asymptotically tend to zero). It seemed that any stable or metastable minima of their potentials would lie in a region where one had no techniques for controlled analysis. (4) String theory seemed to make no useful statements about the observed dark energy. Any plausible estimate suggested a value many, many orders of magnitude too large. This rather bleak picture has been dramatically altered by the discovery that string theory has a vast array of stable and metastable isolated ground states, with and without supersymmetry, and without moduli. The problem, now, appears to be to develop an understanding of this landscape of string vacua. One would like to: (1) Characterize and classify the states of this landscape. How many have features consistent with the Standard Model and cosmological observations. (2) All of these vacua contain numerous additional excitations. Some of these are likely to be at energy scales accessible to the LHC; others relevant to early universe cosmology. Can we classify these possible features, and say which the theory predicts in some definite way? (3) Specifically, does the theory predict warped extra dimensions, supersymmetry, or some other class of phenomena at the TeV scale? From a purely top down perspective, the set of string compactifications include examples with or without low energy supersymmetry, warping, and Technicolor. Each of these possibilities has been developed in interesting regimes of the theory. Whether or not one can say, a priori, that string theory predicts one or more of these phenomena is one of the most important questions in the subject. (4) Again, more specifically: what does the theory have to say about inflationary cosmology? At the level of our current understanding, there are several classes of candidate inflatons, the most dramatic being colliding branes. Many of these inflationary mechanisms lead to potentially observable consequences, such as cosmic strings and non-gaussian corrections to the CMBR. Making sense of this picture probably requires understanding of cosmology at a still more fundamental level, facing the challenges of eternal inflation. In a landscape picture, it may well be essential to understand just how the universe found its way into the observed vacuum; it could well be that some subset of vacua are strongly favored by such considerations. While these questions are challenging, this is the first period when answers to interesting phenomenological questions in string theory appear within reach. The goal of the workshop was to pursue these questions, both from a 'top down' perspective in fundamental string theory and from a 'bottom up' perspective, examining clues from present experiments. The hope is that this work will lead to predictions for LHC physics, as well as frameworks in which to interpret results. Similarly, there is the hope of providing a fundamental framework to understand observational results in cosmology and astrophysics.