# The hadronic contribution to $(g - 2)\mu$

Abstract : The evaluation of the hadronic contribution to the muon magnetic anomaly a_mu is reviewed, including a new estimate using precise results on the pi+pi- spectral function from the KLOE Collaboration. It is found that the KLOE data confirm to some extent the previous e+e- annihilation data in this channel, and accentuate the disagreement with the isospin-breaking-corrected spectral function from tau- -> pi-pi0 nu decays. Correcting for the empirical difference in the mass of the charged and the neutral rho locally improves, but does not resolve this discrepancy. A preliminary reevaluation (including the KLOE data) of the e+e- -based Standard Model prediction of a_mu results in a deviation of 2.7 standard deviations from the BNL measurement.
Document type :
Conference papers

http://hal.in2p3.fr/in2p3-00023231
Contributor : Sabine Starita <>
Submitted on : Thursday, October 14, 2004 - 5:20:02 PM
Last modification on : Wednesday, September 16, 2020 - 4:39:52 PM

### Citation

Andreas Höcker. The hadronic contribution to $(g - 2)\mu$. 32nd International Conference on High-Energy Physics (ICHEP'04), Aug 2004, Beijing, China. ⟨in2p3-00023231⟩

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