The recent interest in a light gauge boson in the framework of an extra U(1) symmetry motivates searches in the mass range below 1 GeV. We present a search for such a particle, the dark photon, in e+e-→Uγ, U→π+π- based on 28 million e+e-→π+π-γ events collected at DAΦNE by the KLOE experiment. The π+ π- production by initial-state radiation compensates for a loss of sensitivity of previous KLOE U→e+e-, μ+μ- searches due to the small branching ratios in the ρ-ω resonance region. We found no evidence for a signal and set a limit at 90% CL on the mixing strength between the photon and the dark photon, ε2, in the U mass range between 527 and 987MeV. Above 700 MeV this new limit is more stringent than previous ones. © 2016 The Authors.
|Titolo:||Limit on the production of a new vector boson in e+e-→Uγ, U→π+π- with the KLOE experiment|
|Data di pubblicazione:||2016|
|Appare nelle tipologie:||1.1 Articolo in rivista|