Published in:
Physical Review Letters 99,12 (2007)
Link to original published article:
http://dx.doi.org/10.1103/PhysRevLett.99.122002
Abstract
We measure the mass of the eta meson using psi(2S)->eta J/psi events acquired with the CLEO-c detector operating at the CESR e(+)e(-) collider. Using the four decay modes eta ->gamma gamma, 3 pi(0), pi(+)pi(-)pi(0), and pi(+)pi(-)gamma, we find M-eta=547.785 +/- 0.017 +/- 0.057 MeV, in which the first uncertainty is statistical and the second systematic. This result has an uncertainty comparable to the two most precise previous measurements and is consistent with that of NA48, but is inconsistent at the level of 6.5 sigma with the much smaller mass obtained by GEM.
Keywords
Physics, Multidisciplinary
Date of this Version
January 2007