RUI: Beyond the Standard Model: model building and phenomenology

Macalester College, Saint Paul MN

Investigators

Abstract

This Proposal addresses the question of how we would experimentally determine that our universe is a 3+1 dimensional brane (membrane) embedded in a higher dimensional space-time. The degrees of freedom that are localized on a flexible brane world generically include four dimensional vector fields. The model independent presence of such brane vectors in physical models with extra-dimensions may in fact provide a first glimpse into the extra dimensions if the brane vectors are lighter than any of the degrees of freedom that can propagate directly into the bulk. The main purpose of the proposed project is to employ a four dimensional effective field theory that describes, to some extent in a universal way, the coupling of the Standard Model fields to the brane vectors in order to study how current and future accelerator experiments and astro-physical observations can be used to probe and constrain scenarios with extra dimensions. The principal investigator and his collaborators have already started an initial study of the brane vector phenomenology. The brane oscillation world volume massive vector (Proca) fields is denoted by X and has a mass MX and a bilinear coupling to the energy-momentuma tensor of the form MX^2/FX ^4 . Data from the lepton colliders LEP-I and LEP-II has been employed to give excluded and allowed regions for the MX-FX parameter space. In particular the annihilation of an electron and positron to produce a single photon and two brane vectors which escape the detector as missing energy is used to delineate the regions of this parameter space. Once LHC is operating the PI intends to use experimental data to map out allowed regions of M-F parameter space. The project will create valuable research training in the field of particle physics for undergraduate students. The PI also plans to give general talks on physics to alumni and staff at the College.