We have studied the vector to pseudoscalar conversion decay phi -> etae(+)e(-), with.. eta -> pi(0)pi(0)pi(0), with the KLOE detector at DAphi NE. The data set of 1.7 fb(-1) of e(+)e(-) collisions at root ssimilar to M-phi contains a clear conversion decay signal of similar to31,000 events from which we measured a value of BR(phi -> eta e(+)e-) =(1.075 +/- 0.007 +/- 0.038) x 10(-4). The same sample is used todetermine the transition form factor by a fit to the e(+)e(-) invariantmass spectrum, obtaining b(phi eta)=( 1.28 +/- 0.10(-0.08)(+0.09))GeV-2, that improves by a factor of five the precision of the previousmeasurement and is in good agreement with VMD expectations. (C) 2015 TheAuthors. Published by Elsevier B.V.
Study of the Dalitz decay φ → ηe+e- with the KLOE detector
Martini M.;
2015-01-01
Abstract
We have studied the vector to pseudoscalar conversion decay phi -> etae(+)e(-), with.. eta -> pi(0)pi(0)pi(0), with the KLOE detector at DAphi NE. The data set of 1.7 fb(-1) of e(+)e(-) collisions at root ssimilar to M-phi contains a clear conversion decay signal of similar to31,000 events from which we measured a value of BR(phi -> eta e(+)e-) =(1.075 +/- 0.007 +/- 0.038) x 10(-4). The same sample is used todetermine the transition form factor by a fit to the e(+)e(-) invariantmass spectrum, obtaining b(phi eta)=( 1.28 +/- 0.10(-0.08)(+0.09))GeV-2, that improves by a factor of five the precision of the previousmeasurement and is in good agreement with VMD expectations. (C) 2015 TheAuthors. Published by Elsevier B.V.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
