On-shell renormalization scheme: Difference between revisions

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{{Short description|Renormalization scheme in quantum field theory}}

{{Renormalization and regularization}}

In [[quantum field theory]], and especially in [[quantum electrodynamics]], the interacting theory leads to infinite quantities that have to be absorbed in a [[renormalization]] procedure, in order to be able to predict measurable quantities. The renormalization scheme can depend on the type of particles that are being considered. For particles that can travel asymptotically large distances, or for low energy processes, the '''on-shell scheme''', also known as the physical scheme, is appropriate. If these conditions are not fulfilled, one can turn to other schemes, like the [[minimal subtraction scheme]] (MS scheme).

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==Vertex function==

A similar reasoning using the [[vertex function]] leads to the renormalization of the electric charge <math>e_r</math>. This renormalization, and the fixing of renormalization terms is done using what is known from classical electrodynamics at large space scales. This leads to the value of the counterterm <math>\delta_1</math>, which is, in fact, equal to <math>\delta_2</math> because of the [[Ward–Takahashi identity]]. It is this calculation that accountaccounts for the [[anomalous magnetic dipole moment]] of fermions.

==Rescaling of the QED Lagrangian==

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* {{Cite book|author=M. Peskin|author2=D. Schroeder|title=An Introduction to Quantum Field Theory|publisher=Addison-Weasley|___location=Reading|year=1995}}

* {{Cite book|author=M. Srednicki|url=http://www.physics.ucsb.edu/~mark/qft.html http://www.physics.ucsb.edu/~mark/qft.html|title=Quantum Field Theory}}

* {{Cite book|author=T. Gehrmann|url=https://www.mitschriften.ethz.ch/main.php?page=3&details=161 https://www.mitschriften.ethz.ch/main.php?page=3&details=161|title=Quantum Field Theory 1}}

[[Category:Quantum field theory]]