First neutrino events
During the November 1993 testrun, the first neutrino events were
recorded with the CHORUS detector. At that moment, a dummy
emulsion was installed,
but the other components (Veto and Trigger planes,
Fiber trackers and Diamond trackers, pulsed Hexagonal Magnet,
EM- and Hadronic calorimeters and Muon Spectrometer) were all
functional.
We have a few samples. The upper plot shows a TOP view, the lower
plot is a SIDE view of the CHORUS detector.
Muon neutrino beam enters from the left.
- Event 54-1387
- Here,
a (muon-)neutrino interacts with material in the calorimeter,
producing some hadronic particles and a (mu+,mu-) pair. This type of event is
not used for the tau-neutrino search, but also contains interesting physics.
- Event 54-1437
- Here, neutrino interacts with material at the very edge of the
(dummy-) emulsion target. Hits are seen in the trigger planes and the
fiber trackers. There is activity in the EM and Hadronic calorimeters,
and one high energy muon is detected, having a secundary
(bremsstrahlung)
interaction in the third section of the muon spectrometer.
This type of event would be a tau-neutrino candidate, where
the one-million fibers will be readout by 58 CCD camera's, and
the emulsion will be scanned within a 300 um diameter
fiducial volume to search for a possible kink-decay.
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home page.
JV / 6 Jan 1994