PT Journal
AU NA62 Collaboration (Cortina Gil, Eea
   Husek, T
TI First search for K+ -> pi(+) nu(nu)over-bar using the decay-in-flight technique
SO Physics Letters B
JI Phys. Lett. B
PY 2019
BP 156
EP 166
VL 791
DI 10.1016/j.physletb.2019.01.067
LA English
AB The NA62 experiment at the CERN SPS reports the first search for K+ -> pi(+) nu(nu) over bar using the decay-in-flight technique, based on a sample of 1.21 x10(11) K+ decays collected in 2016. The single event sensitivity is 3.15 x10(-10), corresponding to 0.267 Standard Model events. One signal candidate is observed while the expected background is 0.152 events. This leads to an upper limit of 14 x10(-10) on the K+ -> pi(+) nu(nu) over bar branching ratio at 95% CL.
ER