Speaker
Evgeniy Kravchenko Budker
(INP Novosibirsk (Russia))
Description
The Super Charm-Tau Factory is under the development at the Budker INP
in Novosibirsk. This will be the e+e collider with the luminosity up
to 10^35 cm^-2s^-1 and the energy at the centre of mass from 2 to 5
GeV. The ‘golden’ process will be the search for the
lepton flavor violation in tau decays: tau -> mu+gamma with the
projected sensitivity Br<10^-9. One of the main background sources for
this process is the decay tau -> pi+pi0+/nu (Br=25%). To suppress such
a background a very powerful muon/pion separation is needed below 1
GeV/c. This task is accessible only with a FARICH.
In 2012 FARICH prototype based on a photon camera with
dimensions of 200x200 mm from Philips Digital Photon Counting (PDPC)
has been tested at CERN. A remarkable particle separation was
achieved with a 4-layer aerogel sample: pi/K separation at 6 GeV/c
momentum is 3.5 sigma, mu/pi separation is 5.3 sigma at 1 GeV/c. The
analysis of the data has shown that the main contribution to the
accuracy of ring radius measurement is coming from aerogel. The
development of focusing aerogels is proceeding in two main
directions: tuning of production technology of multilayer blocks and
development of a new production method with continuous density
(refractive index) gradient along block's depth.
Part of the talk is devoted to the history of the development of
aerogel Cherenkov counters of different types and aerogel production
in Budker Institute of Nuclear physics and Boreskov Institute of Nuclear Physics.
