PT Journal
AU NA48/2 Collaboration (Batley, JRea
   Fiorini, L
TI Search for the dark photon in pi(0) decays
SO Physics Letters B
JI Phys. Lett. B
PY 2015
BP 178
EP 185
VL 746
DI 10.1016/j.physletb.2015.04.068
LA English
AB A sample of 1.69 x 10(7) fully reconstructed pi(0) -> gamma e(+)e(-) decay candidates collected by the NA48/2 experiment at CERN in 2003-2004 is analyzed to search for the dark photon (A') production in the pi(0) -> gamma A' decay followed by the prompt A' -> e(+)e(-) decay. No signal is observed, and an exclusion region in the plane of the dark photon mass m(A') and mixing parameter epsilon(2) is established. The obtained upper limits on epsilon(2) are more stringent than the previous limits in the mass range 9 MeV/c(2) < m(A') < 70 MeV/c(2). The NA48/2 sensitivity to the dark photon production in the K-+/- -> pi(+/-)A' decay is also evaluated.
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