Measurement
of the tau mass
The
tau mass can be measured using the pseudomass method in 3prong tau decays
and using Z to tautau events where both taus decay to hadrons and the tau
direction can be calculated. The first method is expected to be more precise
in Z decays . The expected statistical precision is of order 1 MeV/c^2.
References,
see :
P.
Privitera: "A Measurement of the tau mass", DELPHI Note 9358 PHYS
286

Spectral
functions and determination of alpha_s
By
studying the vector and nonvector spectral functions in hadronic tau decays
one can obtain a measurement of alpha_s on the tau mass scale.
References,
see for example:
Recent
Aleph publication: European Physical Journal C4 (1998) 409 and references
therein.

Strange
spectral functions and determination of the strange quark mass
By
studying the spectral functions in strange tau decays it is possible to
measure the strange quark mass at the tau mass scale. This should be particularly
interesting for DELPHI with the RICH.
References,
see for example:
Recent
Aleph publication: CERNEP99026

CPviolation
in Z>tautau and measurement of the tau weak dipole moment
With
optimised CPsensitive variables constructed from correlations between
different taus in a Z to tautau event it is possible to put a limit on
the weak dipole moment of the tau.
References,
see for example:
M.C.
Chen et al, DELPHI submission to Warsaw conference. Delphi note 96111
Warsaw CONF 38.
Recent
Opal publication: Zeit. fur Physik C74 (1997) 403  412 and references
therein.

Measurement
of the tau electric dipole moment with Z>tautau and gammagamma>tautau
events
Through
the study of radiative Z to tautau events and the production rate of tautau
events in twophoton collisions it is possible to set upper limits on the
tau anomalous magnetic and electric dipole moments.
References,
see for example:
Recent
L3 publication: Phys. Lett. B 434 (1998) 169179 and references therein.

Measurement
of michel parameters using taus produced in W decays
The
fully polarised taus produced in W decays give higher sensitivity to the
polarisation related michel parameters xi and xidelta. Its should
be possible to reach a similar level of precision with the WW data set
produced at LEP 2 as was acheived at LEP1 with the full tau pair sample.
References:
none 