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Larin I, McNulty D, Clinton E, Ambrozewicz P, Lawrence D, Nakagawa I, Prok Y, Teymurazyan A, Ahmidouch A, Asratyan A, Baker K, Benton L, Bernstein AM, Burkert V, Cole P, Collins P, Dale D, Danagoulian S, Davidenko G, Demirchyan R, Deur A, Dolgolenko A, Dzyubenko G, Ent R, Evdokimov A, Feng J, Gabrielyan M, Gan L, Gasparian A, Gevorkyan S, Glamazdin A, Goryachev V, Gyurjyan V, Hardy K, He J, Ito M, Jiang L, Kashy D, Khandaker M, Kingsberry P, Kolarkar A, Konchatnyi M, Korchin A, Korsch W, Kowalski S, Kubantsev M, Kubarovsky V, Li X, Martel P, Matveev V, Mecking B, Milbrath B, Minehart R, Miskimen R, Mochalov V, Mtingwa S, Overby S, Pasyuk E, Payen M, Pedroni R, Ritchie B, Rodrigues TE, Salgado C, Shahinyan A, Sitnikov A, Sober D, Stepanyan S, Stephens W, Underwood J, Vasiliev A, Vishnyakov V, Wood M, Zhou S. New Measurement of the π0 radiative decay width. Phys Rev Lett 2011; 106:162303. [PMID: 21599360 DOI: 10.1103/physrevlett.106.162303] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2010] [Indexed: 05/30/2023]
Abstract
High precision measurements of the differential cross sections for π0 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 π0→γγ decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The π0→γγ 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 Γ(π0→γγ)=7.82±0.14(stat)±0.17(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.
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Affiliation(s)
- I Larin
- Alikhanov Institute for Theoretical and Experimental Physics, Moscow, Russia
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