Soft pion theorem, asymptotic symmetry and new memory effect
High Energy Physics - Theory
2018-01-17 v2 General Relativity and Quantum Cosmology
High Energy Physics - Phenomenology
Abstract
It is known that soft photon and graviton theorems can be regarded as the Ward-Takahashi identities of asymptotic symmetries. In this paper, we consider soft theorem for pions, i.e., Nambu-Goldstone bosons associated with a spontaneously broken axial symmetry. The soft pion theorem is written as the Ward-Takahashi identities of the -matrix under asymptotic transformations. We investigate the asymptotic dynamics, and find that the conservation of charges generating the asymptotic transformations can be interpreted as a pion memory effect.
Cite
@article{arxiv.1709.05018,
title = {Soft pion theorem, asymptotic symmetry and new memory effect},
author = {Yuta Hamada and Sotaro Sugishita},
journal= {arXiv preprint arXiv:1709.05018},
year = {2018}
}
Comments
25 pages, 2 figures, v2: references and discussions added