We have studied the vector to pseudoscalar conversion decay ϕ→ηe+e-, with η→π0π0π0, with the KLOE detector at DAΦNE. The data set of 1.7 fb-1 of e+e- collisions at s~Mϕ contains a clear conversion decay signal of ~31, 000 events from which we measured a value of BR(ϕ→ηe+e-)=(1.075±0.007±0.038)×10-4. The same sample is used to determine the transition form factor by a fit to the e+e- invariant mass spectrum, obtaining bϕη=(1.28±0.10-0.08+0.09) GeV-2, that improves by a factor of five the precision of the previous measurement and is in good agreement with VMD expectations. © 2015 The Authors.
Study of the Dalitz decay ϕ→ηe+e- with the KLOE detector
Fiore, S.
2015-01-01
Abstract
We have studied the vector to pseudoscalar conversion decay ϕ→ηe+e-, with η→π0π0π0, with the KLOE detector at DAΦNE. The data set of 1.7 fb-1 of e+e- collisions at s~Mϕ contains a clear conversion decay signal of ~31, 000 events from which we measured a value of BR(ϕ→ηe+e-)=(1.075±0.007±0.038)×10-4. The same sample is used to determine the transition form factor by a fit to the e+e- invariant mass spectrum, obtaining bϕη=(1.28±0.10-0.08+0.09) GeV-2, that improves by a factor of five the precision of the previous measurement and is in good agreement with VMD expectations. © 2015 The Authors.File in questo prodotto:
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