Title: Radiative decay of the resonant $K^{*}$ and the $\gamma K\to K\pi$ amplitude from lattice QCD

Abstract

We present the first calculation in lattice QCD of the process $$\gamma K \to K\pi$$ in which the narrow $K^*$ vector resonance appears. Using a lattice on which the pion has a mass of 284 MeV, we determine the transition amplitude at 128 points in the $$(Q^2, E_{K\!\pi})$$ plane, and find suitable resonant scattering descriptions. We demonstrate the need to account for $$S$$--wave $$K\pi$$ elastic scattering when converting the finite-volume matrix elements computed in lattice QCD to the physically relevant infinite-volume matrix elements, even when we are primarily interested in the $$P$$--wave amplitude. Analytically continuing parameterizations of the $$\gamma K \to K\pi$$ amplitude to the $K^*$ resonance pole, we obtain the $$K^{*+} \to K^+ \gamma$$ transition form-factor, and compare the $Q^2=0$ value to the corresponding value extracted from the experimental partial-decay width.

Authors:

Radhakrishnan, Archana ;

• Search DOE PAGES for author "Radhakrishnan, Archana"
• Search DOE PAGES for ORCID "0000-0001-9357-1360"

Dudek, Jozef J. ;

• Search DOE PAGES for author "Dudek, Jozef J."
• Search DOE PAGES for ORCID "0000-0003-4327-2121"

Edwards, Robert G. ;

• Search DOE PAGES for author "Edwards, Robert G."
• Search DOE PAGES for ORCID "0000-0002-5667-291X"

for the Hadron Spectrum Collaboration

Publication Date:

Wed Dec 28 00:00:00 EST 2022

Research Org.:

Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Nuclear Physics (NP); USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR); National Science Foundation (NSF); Commonwealth of Virginia Equipment Trust

OSTI Identifier:

1906995

Alternate Identifier(s):

OSTI ID: 1907408

Report Number(s):

JLAB-THY-22-3709; arXiv:2208.13755; DOE/OR/23177-5603
Journal ID: ISSN 2470-0010; PRVDAQ; 114513

Grant/Contract Number:  

SC0018416; AC05-06OR23177; AC05-00OR22725; AC02-05CH11231; OCI-0725070; ACI-1238993; ACI-1548562; PHY-1626177

Resource Type:

Published Article

Journal Name:

Physical Review D

Additional Journal Information:

Journal Name: Physical Review D Journal Volume: 106 Journal Issue: 11; Journal ID: ISSN 2470-0010

Publisher:

American Physical Society

Country of Publication:

United States

Language:

English

Subject:

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; form factors; lattice QCD; kaons