PIRSA:08060034

Unitary Representations of the Conformal Group for pedestrians

APA

Grinstein, B. (2008). Unitary Representations of the Conformal Group for pedestrians. Perimeter Institute. https://pirsa.org/08060034

MLA

Grinstein, Benjamin. Unitary Representations of the Conformal Group for pedestrians. Perimeter Institute, Jun. 02, 2008, https://pirsa.org/08060034

BibTex

          @misc{ pirsa_PIRSA:08060034,
            doi = {10.48660/08060034},
            url = {https://pirsa.org/08060034},
            author = {Grinstein, Benjamin},
            keywords = {},
            language = {en},
            title = {Unitary Representations of the Conformal Group for pedestrians},
            publisher = {Perimeter Institute},
            year = {2008},
            month = {jun},
            note = {PIRSA:08060034 see, \url{https://pirsa.org}}
          }
          

Benjamin Grinstein University of California, San Diego

Collection
Talk Type Conference

Abstract

We comment on several points concerning unparticles which have been overlooked in the literature. One regards Mack\'s unitarity constraint lower bounds on CFT operator dimensions,e.g,. d>= 3 for primary, gauge invariant, vector unparticle operators. We correct the results in the literature to account for this, and also for a needed correction in the form of the propagator for vector and tensor unparticles. We show that the unitarity constraints can be directly related to unitarity requirements on scattering amplitudes of particles, e.g., those of the standard model, coupled to the CFT operators. We also stress the existence of explicit standard model contact terms, which are generically induced by the coupling to the CFT (or any other hidden sector), and are subject to LEP bounds. Barring an unknown mechanism to tune away these contact interactions, they can swamp interference effects generated by the CFT.