# THE N QUANTUM APPROXIMATION, CONCRETE COMPOSITE MODELS OF QUARKS AND LEPTONS, AND PROBLEMS WITH THE NORMALIZATION OF COMPOSITE MASSLESS BOUND STATES

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- DOI: 10.1007/978-1-4615-9343-0_23
- OAI: oai:inspirehep.net:179129
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- INSPIRE-HEP
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## Abstract

We discuss concrete composite models of quarks and leptons using the N-quantum approximation. The first section introduces the main ideas of this approximation, the second section describes the bound-state equations which follow when chiral symmetry is assumed to hold in the Wigner-Weyl mode so that the fermions of the theory, both elementary and composite, have zero mass, and the third section points out a problem with the normalization of composite zero-mass bound states, and offers a suggestion to resolve the problem. We want to conclude this session on composite models of quarks and leptons by discussing concrete composite models. By “concrete” models, we mean models in which the bound states are described in terms of space-time or energy-momentum dependent amplitudes (or wave functions) for their constituents. One must go beyond the quantum number counting or algebraic approach to these models in order to make further progress. The formalism we use to describe the concrete models, the N-quantum approximation (NQA), although not new, is not well-known, so we describe this formalism in Sec. l. In Sec. 2, we apply this formalism to derive bound-state equations for theories in which chiral symmetry is assumed to be exact, so that the composite fermions have zero mass. This work is incomplete, because of the appearance of a problem in the normalization of the bound-state amplitudes for zero mass particles. We describe this problem, and a suggestion to resolve it, in Sec. 3. Field Theory in Elementary Particles Field Theory in Elementary Particles Look Inside Other actions Reprints and Permissions Export citation About this Book Add to Papers Share Share this content on Facebook Share this content on Twitter Share this content on LinkedIn See more