Milestones

2023

Milestone 3 (Lattice):
Extension of finite-volume three-body formalism to scattering of particles with spin
Quartile: Q2, Status: Completed, Responsible: Stephen Sharpe
Papers: JHEP 07 (2023), 226
News: Extension of finite-volume three-body formalism to scattering of particles with spin

Milestone 1 (AmpAn):
Mass-independent partial-wave analysis. Determine the existence of ambiguities in mass independent PWA of two-pseudoscalar meson photoproduction
Quartile: Q3, Status: Completed, Responsible: Adam Szczepaniak
Papers: Phys. Rev. D 108 (2023), 076001
News: No ambiguities in the partial wave analysis for hybrids

Milestone 2 (AmpAn):
Formulate and apply mass-dependent amplitude analysis to describe $\Delta^{++}$ production and explain the momentum transfer behavior of the beam spin asymmetry
Quartile: Q3, Status: Completed, Responsible: Adam Szczepaniak
Papers: Phys. Rev. D 110 (2024), 114012; arXiv:2606.07917; arXiv:2604.22719
News: Reconciling gauge invariance and Reggeization of pion exchange, First determination of vector and tensor couplings from polarized $\pi\Delta$ photoproduction

Milestone 4 (Lattice):
First dispersive extractions of the $\sigma/f_0(500)$ from lattice QCD at various light-quark masses
Quartile: Q3, Status: Completed, Responsible: Arkaitz Rodas Bilbao
Papers: Phys. Rev. D 109 (2024), 034513; Phys. Rev. D 108 (2023), 034513
News: Dispersion relations and Lattice QCD pinpoint the $\sigma$ meson

Milestone 6 (Pheno):
Calculation of decays of $T_{cc}^+(3875)$ in XEFT at LO, and determining implications of the systematic treatment of the nearby coupled 2-body channel for lighter exotic hadrons
Quartile: Q3, Status: Partially completed, Responsible: Eric Braaten
Papers: Phys. Rev. D 109 (2024), 094051

Milestone 5 (Lattice):
Lattice QCD calculation of the $3\pi$ scattering amplitude when $\pi\pi$ can form the $\rho$ resonance
Quartile: Q4, Status: Completed, Responsible: Raúl Briceño
Papers: arXiv:2510.24894

Milestone 8 (Pheno):
Take advantage of the GlueX measurements on photoproduction of vector mesons to perform quantitative analysis of their implications for fundamental properties such as the proton mass radius
Quartile: Q4, Status: Completed, Responsible: Jinfeng Liao
Papers: Nucl. Phys. A 1055 (2025), 123012; Phys. Rev. D 108 (2023), 054018
News: Revisiting $J/\psi$ photoproduction at threshold

2024

Milestone 13 (Lattice):
Extension of finite-volume three-body formalism to more general cases of multiple coupled systems
Quartile: Q2, Status: Completed, Responsible: Stephen Sharpe
Papers: JHEP 07 (2024), 083
News: Three particles with coupled channels

Milestone 14 (Pheno):
Develop model to determine lowest multiplets of hidden-strange tetraquarks and molecules
Quartile: Q4, Status: Completed, Responsible: Rich Lebed
Papers: Phys. Rev. D 112 (2025), 014034

2025

Milestone 16 (AmpAn):
Develop unitary coupled-channel amplitudes compatible with Regge asymptotics for production of three-body final states
Quartile: Q2, Status: Completed, Responsible: Emilie Passemar
Papers: Phys. Rev. D 110 (2024), 114023
News: Towards a unified description of hadron scattering at all energies

Milestone 18 (Lattice):
Lattice QCD calculation of three-body resonance(s)
Quartile: Q2, Status: Partially completed, Responsible: Raúl Briceño
Papers: JHEP 06 (2025), 186; Phys. Lett. B 864 (2025), 139442
News: Two Pathways for Accessing Amplitudes with Left-Hand Cuts in Finite Volumes

Milestone 19 (Lattice):
Lattice QCD calculation of elastic form factors of $\pi\pi$ scattering states
Quartile: Q3, Status: Partially completed, Responsible: Raúl Briceño
Papers: arXiv:2602.20373

Milestone 17 (AmpAn):
Development of formalism to analytically continue three-body integral equations into the complex plane in order to search for resonance pole singularities
Quartile: Q4, Status: Completed, Responsible: Michael Döring
Papers: Phys. Rev. D 108 (2023), 034016

Milestone 23 (Pheno):
Identify and compute distinctive decay modes of the exotics to quasi-stable hadronic final states within the dynamical model previously developed
Quartile: Q4, Status: Completed, Responsible: Eric Swanson
Papers: Phys. Rev. D 109 (2024), 094015
News: A Constituent Model of Light Hybrid Meson Decays