Gauge Theory Bootstrap: Pion amplitudes and low energy parameters

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: He, Yifei, Kruczenski, Martin
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918117651775488
author He, Yifei
Kruczenski, Martin
author_facet He, Yifei
Kruczenski, Martin
contents Following the Gauge Theory Bootstrap method proposed in our previous work [arXiv:2309.12402], we compute pion scattering phase shifts for all partial waves with angular momentum $\ell\le 3$ up to 2 GeV and calculate the low energy $χ$PT coefficients $\bar{\ell}_{1,2,4,6}$. The method looks for the most general S-matrix that matches at low energy the tree level amplitudes of the non-linear sigma model and at high energy, QCD sum rules and form factors. This is a theoretical/numerical calculation that uses as only data the pion mass $m_π$, pion decay constant $f_π$ and the QCD parameters $N_c=3$, $N_f=2$, $m_q$ and $α_s$. All results are in reasonable agreement with experiment. In particular, we find the $ρ(770)$, $f_2(1270)$ and $ρ(1450)$ resonances. The interplay between the UV gauge theory and low energy pion physics is an example of a general situation where we know the microscopic theory as well as the effective theory of long wavelength fluctuations but we want to solve the strongly coupled dynamics at intermediate energies. The bootstrap builds a bridge between the low and high energy by determining the consistent S-matrix that matches both and provides, in this case, a new direction to understand the strongly coupled physics of gauge theories.
format Preprint
id arxiv_https___arxiv_org_abs_2403_10772
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Gauge Theory Bootstrap: Pion amplitudes and low energy parameters
He, Yifei
Kruczenski, Martin
High Energy Physics - Theory
High Energy Physics - Lattice
High Energy Physics - Phenomenology
Following the Gauge Theory Bootstrap method proposed in our previous work [arXiv:2309.12402], we compute pion scattering phase shifts for all partial waves with angular momentum $\ell\le 3$ up to 2 GeV and calculate the low energy $χ$PT coefficients $\bar{\ell}_{1,2,4,6}$. The method looks for the most general S-matrix that matches at low energy the tree level amplitudes of the non-linear sigma model and at high energy, QCD sum rules and form factors. This is a theoretical/numerical calculation that uses as only data the pion mass $m_π$, pion decay constant $f_π$ and the QCD parameters $N_c=3$, $N_f=2$, $m_q$ and $α_s$. All results are in reasonable agreement with experiment. In particular, we find the $ρ(770)$, $f_2(1270)$ and $ρ(1450)$ resonances. The interplay between the UV gauge theory and low energy pion physics is an example of a general situation where we know the microscopic theory as well as the effective theory of long wavelength fluctuations but we want to solve the strongly coupled dynamics at intermediate energies. The bootstrap builds a bridge between the low and high energy by determining the consistent S-matrix that matches both and provides, in this case, a new direction to understand the strongly coupled physics of gauge theories.
title Gauge Theory Bootstrap: Pion amplitudes and low energy parameters
topic High Energy Physics - Theory
High Energy Physics - Lattice
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2403.10772