Neutral pion lifetime measurements and the QCD chiral anomaly
Author(s)Bernstein, Aron M.; Holstein, Barry R.
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A fundamental property of QCD is the presence of the chiral anomaly, which is the dominant component of the π[superscript 0]→γγ decay rate. Based on this anomaly and its small (≃4.5%) chiral correction, a prediction of the π[superscript 0] lifetime can be used as a test of QCD at confinement scale energies. The interesting experimental and theoretical histories of the π[superscript 0] meson are reviewed, from discovery to the present era. Experimental results are in agreement with the theoretical prediction, within the current (≃3%) experimental error; however, they are not yet sufficiently precise to test the chiral corrected result, which is a firm QCD prediction and is known to ≃1% uncertainty. At this level there exist experimental inconsistencies, which require attention. Possible future work to improve the present precision is suggested.
DepartmentMassachusetts Institute of Technology. Department of Physics
Reviews of Modern Physics
American Physical Society
Bernstein, A. M., and Barry R. Holstein 2013Neutral Pion Lifetime Measurements and the QCD Chiral Anomaly. Reviews of Modern Physics 85(1): 49–77. © 2013 American Physical Society
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