The LHC is the world's foremost high-energy physics experimental facility, and will probe distances shorter, and energies higher, than ever before. It will examine the weak interactions, responsible for many natural phenomena, and seek the origin of the masses of the known fundamental particles, known to arise from a Higgs mechanism whose precise nature remains unclear. The LHC might also shed light on dark matter, and might revolutionize our understanding of space-time, through discovery of extra dimensions or Supersymmetry. A full LHC research program requires experts who can work at and across the interface between theory and experiment. This grant proposal is aimed at strengthening this interface at the Institute for Advanced Study (IAS) and Rutgers University theory groups, which already work closely with the Rutgers and Princeton University experimental groups and Princeton theory group. The purpose is to augment their LHC research programs in order to close the scientific gap located at the Theory/Experiment Interface, by hiring and hosting experts who can provide tools and knowledge required by both theorists and experimentalists working on LHC physics. This will greatly expand the range of LHC research possible at these institutions, especially assisting with personnel-intensive activities including standard model background studies, development of Monte Carlo tools, and investigations of search strategies for new physics. The PIs will be involved in both developing new models to describe Beyond the Standard Model Physics, as well as creating an effective theory approach for analyzing and interpreting directly the results coming from LHC. The proposed research includes studies on background removal, using Monte Carlo tools. If a novel signal is seen at the LHC, neither a model-independent approach nor a fully model-dependent approach is appropriate. The PIs propose that once a signal is seen at LHC, they will proceed to build a "model fragment", which in many cases will take the form of an "on-shell effective theory" (OSET). Model fragments were used by the PIs in their successful analysis at the first LHC Olympics workshop, and were developed further into a Monte Carlo tool for wider use. The essential idea is to build a semi-consistent theoretical framework that makes predictions for LHC signals without requiring a fully consistent TeV-scale theory, or in the case of an OSET, possibly without even a fully consistent effective Lagrangian. The PIs will also investigate the Effects of Multiple Soft Jets on Reconstruction and Analysis. The broader impact is to create the nucleus of an LHC center on the East Coast. The IAS and Rutgers, along with Princeton, will form the nucleus of such a center, helping to anchor and enhance the diffuse but substantial research program on the east coast, which is currently scattered around many institutions.. In particular, by training new students and broadening the postdocs at the Theory/Experiment Interface, it would help, over time, to strengthen the entire US particle physics community. Also, by hosting training and research workshops, it would directly benefit other institutions, particularly in the local and regional neighborhood. Most directly, the quick-reaction workshops would foster a more rapid response from the US community to events at the LHC. The PIs also plan a series of training exercises based on the successful "LHC Olympics" model to help in the process of training young students and in retraining postdocs from more formal areas of high-energy theory.
