The ALEPH Detector (Apparatus for LEp PHysics)

ALEPH is a 4$\pi$ detector designed to give as much detailed information as possible about the complex events produced in high energy $\mathrm{e}^+\mathrm{e}^-$ collisions. A superconducting coil 5 metres in diameter and 6 metres long produces a 1.5 Tesla field in the beam direction. Particle detection is accomplished in layers, with each layer performing a particular function.\\ \\A high resolution vertex detector layers of silicon with double-sided readout provides $r$, $\phi$ and $z$ coordinates and identifies decay vertices of tau leptons, charm and beauty hadrons. \\ \\The Inner Tracking Chamber (ITC) is a cylindrical drift chamber with eight axial layers. It gives a high spatial resolution and good track separation, and is also an essential part of the trigger system.\\ \\The Time Projection Chamber (TPC), 3.6 metres in diameter and 4.4 metres long, measures track momenta and directions. It also provides up to 338 energy loss measurements per track for particle identification. The momentum resolution of the three tracking detectors is $\sigma$(1/$p_T$) = ~~6 $\cdot$ $10^{-4}$ $(GeV/c)^{-1}$.\\ \\The electromagnetic calorimeter (ECAL) is a lead/wire chamber sandwich operated in proportional mode. It is read out in projective towers of $0.9^{\circ}\times