Combining b-tagging methods using a neural network approach

The most powerful method of b-jet tagging in ATLAS experiment is based on the relatively long lifetime of B-hadrons and therefore a separation of the B-hadron decay vertex from the pp interaction point . The efficiency of the method is improved while combined with another tagging algorithm using low-p_T electrons from semileptonic b-quark decays. For the first time the neural network approach is used to combine both tagging algorithms. Rejection of background u-jets is improved by 16% and c-jets by 10% comparing to the pure vertex method.