Measurement of the transition form factor in ϕ → ηe+e − and ϕ → π0e+e− decays at KLOE
Laboratori Nazionali di Frascati - INFN -
a e-mail: email@example.com
Published online: 26 November 2014
In this work we present a study of the Dalitz decay ϕ → ηe+e−, with η → π0π0π0, performed using 1.7 fb−1 of e+e− collisions collected at KLOE in the 2004-2005 data taking period. The resulting branching fraction is: BR(ϕ → ηe+e−) = (1.075 ± 0.007(stat.) ± 0.038(norm.)) × 10−4. We have also studied the invariant mass of the dilepton system, extracting the slope of the transition form factor: b ϕη =(1.17 ± 0.10 −0.11+0.07) GeV−2. The ϕ → π0e+e− rare decay is also being studied using the same data sample. The branching ratio will be measured, with a consistent reduction of the actual total uncertainty. The double off shell π0 Transition Form Factor will also be measured for the first time in the time-like region, with the momentum transfer given by the e+e− invariant mass.
© Owned by the authors, published by EDP Sciences, 2014
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.