Physical Review Letters
We present the first ab initio calculation of a radiative transition of a hadronic resonance within quantum chromodynamics (QCD). We compute the amplitude for 𝜋𝜋→𝜋𝜸⋆, as a function of the energy of the 𝜋𝜋 pair and the virtuality of the photon, in the kinematic regime where 𝜋𝜋 couples strongly to the unstable ρ resonance. This exploratory calculation is performed using a lattice discretization of QCD with quark masses corresponding to mπ ≈ 400 MeV. We obtain a description of the energy dependence of the transition amplitude, constrained at 48 kinematic points, that we can analytically continue to the ρ pole and identify from its residue the ρ→𝜋𝜸⋆ form factor.
Original Publication Citation
Briceño, R.A., Dudek, J.J., Edwards, R.G., Shultz, C.J., Thomas, C.E., Wilson, D.J. (2015) Resonant 𝜋⁺𝜸 → 𝜋⁺𝜋⁰ amplitude from quantum chromodynamics. Physical Review Letters, 115(24), 1-5, Article 242001. https://doi.org/10.1103/PhysRevLett.115.242001
0000-0003-1109-1473 (Briceño), 0000-0003-4327-2121 (Dudek), 0000-0003-2364-1161 (Wilson)
Briceño, Raúl A.; Dudek, Jozef J.; Edwards, Robert G.; Shultz, Christian J.; Thomas, Christopher E.; and Wilson, David J., "Resonant 𝜋⁺𝜸 → 𝜋⁺𝜋⁰ Amplitude from Quantum Chromodynamics" (2015). Physics Faculty Publications. 623.