Daniele Bettinelli

THE SU(2) ⊗ U(1) ELECTROWEAK MODEL BASED ON THE NONLINEARLY REALIZED GAUGE GROUP

In the present paper, that is the second part devoted to the construction of an electroweak model based on a nonlinear realization of the gauge group SU(2) U(1), we study the tree-level vertex functional with all the sources necessary for the functional formulation of the relevant symmetries (Local Functional Equation, Slavnov‐Taylor identity, Landau Gauge Equation) and for the symmetric removal of the divergences. The Weak Power Counting criterion is proven in the presence of the novel sources. The local invariant solutions of the functional equations are constructed in order to represent the counterterms for the one-loop subtractions. The bleaching technique is fully extended to the fermion sector. The neutral sector of the vector mesons is analyzed in detail in order to identify the physical fields for the photon and the Z boson. The identities necessary for the decoupling of the unphysical modes are fully analyzed. These latter results are crucially bound to the Landau gauge used throughout the paper.

Massive Yang-Mills theory based on the nonlinearly realized gauge group

We propose a subtraction scheme for a massive Yang-Mills theory realized via a nonlinear representation of the gauge group [here

FURTHER COMMENTS ON THE SYMMETRIC SUBTRACTION OF THE NONLINEAR SIGMA MODEL

SU(2)

One-loop self-energies in the electroweak model with a nonlinearly realized gauge group

]. It is based on the subtraction of the poles in

Path-integral over non-linearly realized groups and hierarchy solutions

D\ensuremath{-}4

The hierarchy principle and the large mass limit of the linear sigma model

of the amplitudes, in dimensional regularization, after a suitable normalization has been performed. Perturbation theory is in the number of loops, and the procedure is stable under iterative subtraction of the poles. The unphysical Goldstone bosons, the Faddeev-Popov ghosts, and the unphysical mode of the gauge field are expected to cancel out in the unitarity equation. The spontaneous symmetry breaking parameter is not a physical variable. We use the tools already tested in the nonlinear sigma model: hierarchy in the number of Goldstone boson legs and weak-power-counting property (finite number of independent divergent amplitudes at each order). It is intriguing that the model is naturally based on the symmetry

Gauge dependence in the nonlinearly realizedmassive SU(2) gauge theory 1

SU(2{)}_{L}

Nonlinearly Realized Gauge Theories for LHC Physics

local

Renormalization group equation for weakly power-counting renormalizable theories

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