Topics in Particle Theory

College Of William And Mary, Williamsburg VA

Investigators

Abstract

The Large Hadron Collider will soon unravel the mystery of electroweak symmetry breaking (EWSB). The PI's propose to study new models of EWSB using the AdS/CFT correspondence as an essential tool. Three types of models will be considered: D-brane models, new 5D models that are motivated by D-brane constructions, and 5D models in AdS space. Models of the first type are D-brane constructions that are known to break chiral symmetries dynamically. Models of the second type have a topology that is motivated by these D-brane systems, but are five-dimensional and otherwise phenomenologically inspired. Models of the third type take a well-known holographic model of QCD in 5D AdS space as a template for a dynamical EWSB sector. The PI's will study a range of phenomenological issues including precision electroweak constraints, unitarity, naturalness, and electroweak baryogenesis. The Pi's also propose to study the phenomenology of the Lee-Wick Standard Model. This is an extension of the Standard Model that is free of quadratic divergences and which involves new particles at the TeV scale that participate in the cancellation of divergences. A simple holographic model of QCD defined on a slice of five-dimensional AdS space has proved to be remarkably successful in describing the masses and couplings of the pseudoscalar, vector and axial-vector mesons. Motivated by the observation that baryons appear naturally in stringy holographic models as topological solitons, the PI's propose to investigate whether baryons can also be described as stable solitonic objects in 5D holographic models of QCD that are formulated in AdS space. The broader impact of the proposed work is that it will stimulate interdisciplinary collaborations, further the education of undergraduate and PhD research students, involve members of under-represented groups, and promote high-energy particle physics in the southeastern part of the United States. The PI's participate in several REU activities at William and Mary and have supervise seven undergraduate theses.