Search for nuclearites by the satellite-based TUS air fluorescence detector

Nuclearites are a hypothetical massive strange quark matter. They are supposed to be gravitationally trapped in Our Galaxy. Their absolute velocity is considered to be similar to that of the galactic rotation near the Sun. When the nucleartite traverses in the medium, a part of the energy loss is converted to the light radiation. This principle has been used for nuclearite searches made by underground or underwater neutrino observatories. In the night atmosphere, such an event form a meteor-like moving light spot. In the present work, we applied this detection method to search for nuclearites using the TUS (Tracking Ultraviolet Setup) instrument, the first orbital air fluorescence detector on the Lomonosov satellite launched in April 2016. The apparatus consisted of a ∼2 m^2 segmented Fresnel reflector viewed by 256 photomultiplier tubes with readout electronics. TUS was operated in the meteor observation mode during the mission that allows the register luminous moving event with a time resolution of 6.6 ms. Since the area simultaneously observed by TUS in the orbit at ∼485 km height, is on the order of ∼ 6000 km^2 that provides a potential to accumulate exposures comparable to the former experiments within on the order of days. In the present contribution, we report the preliminary results of the first nuclearite search using the satellite-based air fluorescence detector and relevant simulation studies.