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.
Study of the Dalitz decay φ → ηe+e- with the KLOE detector / Babusci, D.; Ceradini, Filippo; DI CICCO, Alessandro; Loffredo, Salvatore; PRADO LONGHI, Ivan. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 742:(2015), pp. 1-6. [10.1016/j.physletb.2015.01.011]
Study of the Dalitz decay φ → ηe+e- with the KLOE detector
LOFFREDO, SALVATORE;
2015
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
