Search for the exotic Θ+ resonance in the NOMAD experiment

A search for exotic Θ+ baryon via Θ+ →p+K0S decay mode in the NOMAD νμN data is reported. The special background generation procedure was developed. The proton identification criteria are tuned to maximize the sensitivity to the Θ+ signal as a function of xF which allows to study the Θ+ production mechanism. We do not observe any evidence for the Θ+ state in the NOMAD data. We provide an upper limit on Θ+ production rate at 90% CL as 2.13×10−3 per neutrino interaction.