Speaker
Emilie Maurice
(University of Liverpool (GB))
Description
The main goal of the NA62 experiment at the CERN SPS accelerator is to measure the branching ratio of the ultra-rare K+ → π+νν ̄ decay with 10% accuracy. This will be achieved by detecting about 100 K+ → π+νν ̄ decays with a ratio signal/background ∼ 10 in 2-3 years of data taking. NA62 will use a 750MHz high-energy un-separated charged hadron beam, with kaons corresponding to 6% of the beam, and a kaon decay-in-flight technique. Since pions and protons cannot be separated efficiently from kaons at the beam level, the identification of kaons within the high-intensity NA62 beam is mandatory. The time information is also essential to reconstruct the K+ decay and to guarantee the rejection of background induced by accidental overlap of events in the detector. A differential Cherenkov detector (CEDAR) filled with Nitrogen gas, and placed in the incoming beam, will perform the fast identification of kaons, before their decays, with an efficiency of at least 95%. The CEDAR is insensitive to pions and protons and will provide precise time information with a resolution of at least 100ps. To stand the particle rate and to meet the performances required, an upgraded version (CEDAR-KTAG) with new photon detectors, readout, mechanics, cooling and safety systems has been realised for NA62. The measured time resolutions and efficiency will be presented.
Author
Cristina Lazzeroni
(University of Birmingham (GB))
