Regularization in nonperturbative extensions of effective field theory
Files
(Published version)
Date
2022
Authors
Abell, C.D.
Leinweber, D.B.
Thomas, A.W.
Wu, J.-J.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Physical Review D (particles, fields, gravitation, and cosmology), 2022; 106(3)
Statement of Responsibility
Curtis D. Abell, Derek B. Leinweber, Anthony W. Thomas, and Jia-Jun Wu
Conference Name
Abstract
The process of renormalization in nonperturbative Hamiltonian effective field theory (HEFT) is examined in the Δ-resonance scattering channel. As an extension of effective field theory incorporating the Lüscher formalism, HEFT provides a bridge between the infinite-volume scattering data of experiment and the finite-volume spectrum of energy eigenstates in lattice QCD. HEFT also provides phenomenological insight into the basis-state composition of the finite-volume eigenstates via the state eigenvectors. The Hamiltonian matrix is made finite through the introduction of finite-range regularization. The extent to which the established features of this regularization scheme survive in HEFT is examined. In a singlechannel πN analysis, fits to experimental phase shifts withstand large variations in the regularization parameter Λ, providing an opportunity to explore the sensitivity of the finite-volume spectrum and state composition on the regulator. While the Lüscher formalism ensures the eigenvalues are insensitive to Λ variation in the single-channel case, the eigenstate composition varies with Λ; the admission of shortdistance interactions diminishes single-particle contributions to the states. In the two-channel πN, πΔ analysis, Λ is restricted to a small range by the experimental data. Here the inelasticity is particularly sensitive to variations in Λ and its associated parameter set. This sensitivity is also manifest in the finitevolume spectrum for states near the opening of the πΔ scattering channel. Future high-quality lattice QCD results will be able to discriminate Λ, describe the inelasticity, and constrain a description of the basis-state composition of the energy eigenstates. Finally, HEFT has the unique ability to describe the quark-mass dependence of the finite-volume eigenstates. The robust nature of this capability is presented and used to confront current state-of-the-art lattice QCD calculations.
School/Discipline
Dissertation Note
Provenance
Description
Access Status
Rights
© 2022, American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Funded by SCOAP3