English

Renormalization and running in the 2D $CP(1)$ model

High Energy Physics - Theory 2024-08-26 v1 High Energy Physics - Phenomenology

Abstract

We calculate the scattering amplitude in the two dimensional CP(1)CP(1) model in a regularization scheme independent way. When using cutoff regularization, a new Feynman rule from the path integral measure is required if one is to preserve the symmetry. The physical running of the coupling with renormalization scale arises from a UV finite Feynman integral in all schemes. We reproduce the usual result with asymptotic freedom, but the pathway to obtaining the beta function can be different in different schemes. We also comment on the way that this model evades the classic argument by Landau against asymptotic freedom in non-gauge theories.

Keywords

Cite

@article{arxiv.2408.13142,
  title  = {Renormalization and running in the 2D $CP(1)$ model},
  author = {Diego Buccio and John F. Donoghue and Gabriel Menezes and Roberto Percacci},
  journal= {arXiv preprint arXiv:2408.13142},
  year   = {2024}
}

Comments

11 pages, 1 figure

R2 v1 2026-06-28T18:22:16.708Z