Speaker
Summary
OPERA is a long-baseline neutrino oscillation appearance experiment designed to
obtain an unambiguous signature of $\nu_{\mu}
\rightarrow \nu_{\tau}$ oscillation. The detector, located in the
underground Gran Sasso Laboratories,
plans to detect $\nu_{\tau}$'s in the CERN to Gran Sasso (CNGS) $\nu_{\mu}$
beam,
which is optimised for $\nu_{\tau}$ appearance.
OPERA is an hybrid experiment with electronic detectors, iron magnets and Emulsion
Cloud Chambers (ECC).
The ECC combines in one cell the high tracking precision of nuclear emulsions
($\sim$0.1 $\mu$m) and the large
target mass of the lead plates. The basic element, the ``brick'', has
dimensions of 12.7$\times$10.2$\times$7.5 cm$^3$; it is a sequence of 56 lead (1
mm
thick) and 57 emulsion films
(44 $\mu$m thick emulsion layers on either side of a 205 $\mu$m plastic base). The
total length of an OPERA ECC
module is about 10 $X_0$.
In addition of its very good tracking information capabiliy,
allowing for instance the detection of short-lived particles, the
ECC can be used as a fine sampling
electromagnetic calorimeter. We will report the method developped to reconstruct the
electromagnetic showers with ECC and the energy measurement in the 1-10 GeV
range.
The achieved energy resolution
is about $\frac{\sigma_E}{E}= \frac{40\%}{\sqrt(E)}$.
We will also
present the momentum measurement of the charged hadron using Mutiple Coulomb
Scattering used for the
hadronic shower reconstruction.
