Resonant π^{+}γ→π^{+}π^{0} Amplitude from Quantum Chromodynamics.
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Peer-reviewed
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Authors
Briceño, Raúl A
Dudek, Jozef J
Edwards, Robert G
Shultz, Christian J
Thomas, Christopher E
Abstract
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 m_{π}≈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.
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Hadron Spectrum Collaboration
Journal Title
Phys Rev Lett
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Journal ISSN
0031-9007
1079-7114
1079-7114
Volume Title
115
Publisher
American Physical Society (APS)
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Sponsorship
Science and Technology Facilities Council (ST/L000385/1)
Support is provided by the U.S. Department of Energy contract DEAC05-06OR23177 under which Jefferson Science Associates manages Jefferson Lab, the Early Career award contract DE- SC0006765, and the JSA Graduate Fellowship program. Support is also provided by the U.K. Science and Technology Facilities Council [grant number ST/L000385/1].