2010/09/09 by I. Larin, D. McNulty, E. Clinton +95 · 4 citations
Physics and Astronomy · #Nuclear physics research studies #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #nucl-ex
paper · pdf · doi:10.1103/physrevlett.106.162303
published as Phys.Rev.Lett.106:162303,2011 · 4 pages, 5 figures
arxiv created 2010/09/09 · openalex publication_date 2011/04/20 · arxiv updated 2011/05/09 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
High precision measurements of the differential cross sections for \ensuremathπ0 photoproduction at forward angles for two nuclei, 12C and 208Pb, have been performed for incident photon energies of 4.9--5.5 GeV to extract the \ensuremathπ0\ensuremath→\ensuremathγ\ensuremathγ decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The \ensuremathπ0\ensuremath→\ensuremathγ\ensuremathγ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is \ensuremathΓ(\ensuremathπ0\ensuremath→\ensuremathγ\ensuremathγ)=7.82\ifmmode±\else\textpm\fi0.14(stat)\ifmmode±\else\textpm\fi0.17(syst) eV. With the 2.8% total uncertainty, this result is a factor of 2.5 more precise than the current Particle Data Group average of this fundamental quantity, and it is consistent with current theoretical predictions.