The HLS approach to (g − 2)μ : A Solution to the “τ versus e+e−” Puzzle
LPNHE des Universitùs Paris VI et Paris VII, IN2P3/CNRS, 4 Place Jussieu, 75252 Paris, France
Published online: 26 April 2016
The Hidden Local Symmetry (HLS) Model provides a framework able to encompass several physical processes and gives a unfied description of these in an energy range extending up to the ø mass. Supplied with appropriate symmetry breaking schemes, the HLS Model gives a broken Effective Lagrangian (BHLS). The BHLS Lagrangian gives rise to a fit procedure in which a simultaneous description of the e+e− annihilations to π+π−, π0γ, ηγ, π+π−π0, K+K−, KLKS and of the dipion spectrum in the decay τ±→π± π0v can be performed. Supplemented with a few pieces of information on the ρ0 − ω – ø system, the τ dipion spectrum is shown to predict accurately the pion form factor in e+e− annihilations. Physics results derived from global fits involving or excluding the τ dipion spectra are found consistent with each others. Therefore, no obvious mismatch between the τ and e+e− physics properties arises and the τ − e+e− puzzle vanishes within the broken HLS Model.
© Owned by the authors, published by EDP Sciences, 2016
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