VELO-TT matching and momentum determination at Level-1 trigger

The fast track reconstruction in the TT station and momentum determination at the trigger Level-1 is presented. The initial step is a determination of optimal track parameters at the VELO exit point. Then a pattern recognition fulfilling the Level-1 requirements is performed in the TT station. For good quality track candidates the momentum is estimated by a measurement of the track deflection in the fringe magnetic field between VELO and TT.