Secondorder fermionsTools Espin, Johnny (2015) Secondorder fermions. PhD thesis, University of Nottingham.
AbstractIt has been proposed several times in the past that one can obtain an equivalent, but in many aspects simpler description of fermions by first reformulating their firstorder (Dirac) Lagrangian in terms of twocomponent spinors, and then integrating out the spinors of one chirality (e.g.primed or dotted). The resulting new Lagrangian is secondorder in derivatives, and contains twocomponent spinors of only one chirality. The new secondorder formulation simplifies the fermion Feynman rules of the theory considerably, e.g. the propagator becomes a multiple of an identity matrix in the field space. The aim of this thesis is to work out the details of this formulation for theories such as Quantum Electrodynamics, and the Standard Model of elementary particles. After having developed the tools necessary to establish the secondorder formalism as an equivalent approach to spinor field theories, we proceed with some important consistency checks that the new formulation is required to pass, namely the presence or absence of anomalies in their perturbative and nonperturbative description, and the unitarity of the SMatrix derived from their Lagrangian. Another aspect which is studied is unification, where we seek novel gaugegroups that can be used to embed all of the Standard Model content: forces and fermionic representations. Finally, we will explore the possibility to unify gravity and the Standard Model when the former is seen as a diffeomorphism invariant gaugetheory.
Actions (Archive Staff Only)
