dc.creator | Briceño, Raúl A | |
dc.creator | Dudek, Jozef J | |
dc.creator | Edwards, Robert G | |
dc.creator | Shultz, Christian J | |
dc.creator | Thomas, Christopher Edward | |
dc.creator | Wilson, David John | |
dc.creator | Hadron, Spectrum Collaboration | |
dc.date.accessioned | 2016-05-18 | |
dc.date.accessioned | 2018-11-24T23:18:58Z | |
dc.date.available | 2016-06-17T11:20:55Z | |
dc.date.available | 2018-11-24T23:18:58Z | |
dc.date.issued | 2016-06-10 | |
dc.identifier | https://www.repository.cam.ac.uk/handle/1810/256359 | |
dc.identifier.uri | http://repository.aust.edu.ng/xmlui/handle/123456789/3381 | |
dc.description.abstract | We present a determination of the P-wave ππ→πγ$^{⋆}$ transition amplitude from lattice quantum chromodynamics. Matrix elements of the vector current in a finite volume are extracted from three-point correlation functions, and from these we determine the infinite-volume amplitude using a generalization of the Lellouch-Lüscher formalism. We determine the amplitude for a range of discrete values of the ππ energy and virtuality of the photon and observe the expected dynamical enhancement due to the ρ resonance. Describing the energy dependence of the amplitude, we are able to analytically continue into the complex energy plane and from the residue at the ρ pole extract the ρ→πγ$^{⋆}$ transition form factor. This calculation, at m$_{π}$ ≈ 400 MeV, is the first to determine the form factor of an unstable hadron within a first principles approach to QCD. | |
dc.language | en | |
dc.publisher | American Physical Society | |
dc.publisher | Physical Review D | |
dc.title | ππ→πγ$^{∗}$ amplitude and the resonant ρ→πγ$^{∗}$ transition from lattice QCD | |
dc.type | Article | |