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arXiv · 0907.0521

Extraction of the light quark mass ratio from the decays psi' --> J/psi pi^0 (eta)

Feng-Kun Guo·Christoph Hanhart·Ulf-G. Meißner
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Abstract

Light quark masses are important fundamental parameters of the Standard Model. The decays psi'-->J/psi pi^0 (eta) were widely used in determining the light quark mass ratio m_u/m_d. However, there is a large discrepancy between the resulting value of m_u/m_d and the one determined from the light pseudoscalar meson masses. Using the technique of non-relativistic effective field theory, we show that intermediate charmed meson loops lead to a sizeable contribution to the decays and hence make the psi'-->J/psi pi^0 (eta) decays not suitable for a precise extraction of the light quark mass ratio.

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Feng-Kun Guo, Christoph Hanhart, Ulf-G. Meißner. 2010-02-16. Extraction of the light quark mass ratio from the decays psi' --> J/psi pi^0 (eta). https://doi.org/10.1103/physrevlett.103.082003

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