MIT{CTP 5076 Navigating Collinear Superspace Timothy Cohen,a Gilly Elor,b Andrew J. Larkoski,c and Jesse Thaler d;e aInstitute of Theoretical Science, University of Oregon, Eugene, OR 97403, U.S.A. bDepartment of Physics, Box 1560, University of Washington, Seattle, WA 98195, U.S.A. cPhysics Department, Reed College, Portland, OR 97202, U.S.A. dCenter for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, U.S.A. eDepartment of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138, U.S.A. E-mail:
[email protected],
[email protected],
[email protected],
[email protected] Abstract: We introduce a new set of effective field theory rules for constructing La- grangians with N = 1 supersymmetry in collinear superspace. In the standard superspace treatment, superfields are functions of the coordinates xµ; θα; θyα_ , and supersymmetry preservation is manifest at the Lagrangian level in part due to the inclusion of auxiliary F - and D-term components. By contrast, collinear superspace depends on a smaller set of coordinates xµ; η; ηy, where η is a complex Grassmann number without a spinor index. This provides a formulation of supersymmetric theories that depends exclusively on propa- gating degrees of freedom, at the expense of obscuring Lorentz invariance and introducing inverse momentum scales. After establishing the general framework, we construct collinear superspace Lagrangians for free chiral matter and non-Abelian gauge fields. For the latter construction, an important ingredient is a superfield representation that is simultaneously chiral, anti-chiral, and real; this novel object encodes residual gauge transformations on the light cone.