The development of high performance online tracker for High Level Trigger of Muon Spectrometer of ALICE

The Muon Spectrometer (MS) of the ALICE experiment at LHC is equipped with a HLT (High Level Trigger), whose aim is to improve the accuracy of the trigger cuts delivered at the L0 stage. A computational challenge of real-time event reconstruction is satisfied to achieve this software trigger cut of the HLT. After the description of the online algorithms, the performance of the online tracker is compared with that of the offline tracker using the measured pp collisions at $\sqrt{s}=7$ TeV.