Inclusive rates from smeared spectral densities in the two-dimensional O(3) non-linear σ-model

Abstract This work employs the spectral reconstruction approach of ref. [1] to determine an inclusive rate in the 1 + 1 dimensional O(3) non-linear σ-model, analogous to the QCD part of e + e − → hadrons. The Euclidean two-point correlation function of the conserved current j is computed using Monte...

Full description

Bibliographic Details
Main Authors: John Bulava, Maxwell T. Hansen, Michael W. Hansen, Agostino Patella, Nazario Tantalo
Format: Article
Language:English
Published: SpringerOpen 2022-07-01
Series:Journal of High Energy Physics
Subjects:
Online Access:https://doi.org/10.1007/JHEP07(2022)034
_version_ 1828760476556722176
author John Bulava
Maxwell T. Hansen
Michael W. Hansen
Agostino Patella
Nazario Tantalo
author_facet John Bulava
Maxwell T. Hansen
Michael W. Hansen
Agostino Patella
Nazario Tantalo
author_sort John Bulava
collection DOAJ
description Abstract This work employs the spectral reconstruction approach of ref. [1] to determine an inclusive rate in the 1 + 1 dimensional O(3) non-linear σ-model, analogous to the QCD part of e + e − → hadrons. The Euclidean two-point correlation function of the conserved current j is computed using Monte Carlo lattice field theory simulations for a variety of spacetime volumes and lattice spacings. The spectral density of this correlator is related to the inclusive rate for j → X in which all final states produced by the external current are summed. The ill-posed inverse problem of determining the spectral density from the correlation function is made tractable through the determination of smeared spectral densities in which the desired density is convolved with a set of known smearing kernels of finite width ϵ. The smooth energy dependence of the underlying spectral density enables a controlled ϵ → 0 extrapolation in the inelastic region, yielding the real-time inclusive rate without reference to individual finite-volume energies or matrix elements. Systematic uncertainties due to cutoff effects and residual finite-volume effects are estimated and taken into account in the final error budget. After taking the continuum limit, the results are consistent with the known analytic rate to within the combined statistical and systematic errors. Above energies where 20-particle states contribute, the overall precision is sufficient to discern the four-particle contribution to the spectral density.
first_indexed 2024-12-11T01:14:34Z
format Article
id doaj.art-531f1b131f804ecc8abb2362de2631d4
institution Directory Open Access Journal
issn 1029-8479
language English
last_indexed 2024-12-11T01:14:34Z
publishDate 2022-07-01
publisher SpringerOpen
record_format Article
series Journal of High Energy Physics
spelling doaj.art-531f1b131f804ecc8abb2362de2631d42022-12-22T01:25:56ZengSpringerOpenJournal of High Energy Physics1029-84792022-07-012022713610.1007/JHEP07(2022)034Inclusive rates from smeared spectral densities in the two-dimensional O(3) non-linear σ-modelJohn Bulava0Maxwell T. Hansen1Michael W. Hansen2Agostino Patella3Nazario Tantalo4Deutsches Elektronen-Synchrotron DESYHiggs Centre for Theoretical Physics, School of Physics and Astronomy, The University of EdinburghUniversity of Graz, Institute for PhysicsInstitut für Physik und IRIS Adlershof, Humboldt-Universität zu BerlinUniversity and INFN of Roma Tor VergataAbstract This work employs the spectral reconstruction approach of ref. [1] to determine an inclusive rate in the 1 + 1 dimensional O(3) non-linear σ-model, analogous to the QCD part of e + e − → hadrons. The Euclidean two-point correlation function of the conserved current j is computed using Monte Carlo lattice field theory simulations for a variety of spacetime volumes and lattice spacings. The spectral density of this correlator is related to the inclusive rate for j → X in which all final states produced by the external current are summed. The ill-posed inverse problem of determining the spectral density from the correlation function is made tractable through the determination of smeared spectral densities in which the desired density is convolved with a set of known smearing kernels of finite width ϵ. The smooth energy dependence of the underlying spectral density enables a controlled ϵ → 0 extrapolation in the inelastic region, yielding the real-time inclusive rate without reference to individual finite-volume energies or matrix elements. Systematic uncertainties due to cutoff effects and residual finite-volume effects are estimated and taken into account in the final error budget. After taking the continuum limit, the results are consistent with the known analytic rate to within the combined statistical and systematic errors. Above energies where 20-particle states contribute, the overall precision is sufficient to discern the four-particle contribution to the spectral density.https://doi.org/10.1007/JHEP07(2022)034Lattice Quantum Field TheorySigma Models
spellingShingle John Bulava
Maxwell T. Hansen
Michael W. Hansen
Agostino Patella
Nazario Tantalo
Inclusive rates from smeared spectral densities in the two-dimensional O(3) non-linear σ-model
Journal of High Energy Physics
Lattice Quantum Field Theory
Sigma Models
title Inclusive rates from smeared spectral densities in the two-dimensional O(3) non-linear σ-model
title_full Inclusive rates from smeared spectral densities in the two-dimensional O(3) non-linear σ-model
title_fullStr Inclusive rates from smeared spectral densities in the two-dimensional O(3) non-linear σ-model
title_full_unstemmed Inclusive rates from smeared spectral densities in the two-dimensional O(3) non-linear σ-model
title_short Inclusive rates from smeared spectral densities in the two-dimensional O(3) non-linear σ-model
title_sort inclusive rates from smeared spectral densities in the two dimensional o 3 non linear σ model
topic Lattice Quantum Field Theory
Sigma Models
url https://doi.org/10.1007/JHEP07(2022)034
work_keys_str_mv AT johnbulava inclusiveratesfromsmearedspectraldensitiesinthetwodimensionalo3nonlinearsmodel
AT maxwellthansen inclusiveratesfromsmearedspectraldensitiesinthetwodimensionalo3nonlinearsmodel
AT michaelwhansen inclusiveratesfromsmearedspectraldensitiesinthetwodimensionalo3nonlinearsmodel
AT agostinopatella inclusiveratesfromsmearedspectraldensitiesinthetwodimensionalo3nonlinearsmodel
AT nazariotantalo inclusiveratesfromsmearedspectraldensitiesinthetwodimensionalo3nonlinearsmodel