Measurement of the phi -> pi(0)e(+)e(-) transition form factor with the KLOE detector

作者：Anastasi A; Babusci D^*; Bencivenni G; Berlowski M; Bloise C; Bossi F; Branchini P; Budano A; Balkestahl L Caldeira; Cao B; Ceradini F; Ciambrone P; Curciarello F; Czerwinski E; D'Agostini G; Dane E; De Leo V; De Lucia E; De Santis A; De Simone P; Di Cicco A; Di Domenico A; Di Salvo R; Domenici D; D'Uffizi A; Fantini A; Felici G; Fiore S; Gajos A; Gauzzi P; Giardina G; Giovannella S; Graziani E; Happacher F; Heijkenskjold L

来源：Physics Letters B, 2016, 757: 362-367.

DOI：10.1016/j.physletb.2016.04.015

• e(+)e(-) collisions
• Conversion decay
• Transition form factor

A measurement of the vector to pseudoscalar conversion decay phi -> pi(0)e(+)e(-) with the KLOE experiment is presented. A sample of similar to 9500 signal events was selected from a data set of 1.7 fb(-1) of e(+)e(-) collisions at root s similar to m(phi) collected at the DA Phi NE e(+)e(-) collider. These events were used to perform the first measurement of the transition form factor vertical bar F(phi pi)0(q(2))vertical bar and a new measurement of the branching ratio of the decay: BR (phi -> pi(0)e(+)e(-)) = (1.35 +/- 0.05(-0.10)(+0.05)) x 10(-5). The result improves significantly on previous measurements and is in agreement with theoretical predictions.

• 出版日期2016-6-10