Measurement of $t\bar t$ production cross section in the lepton+jets channel using Jet Probability $b$-tagging at CDF

We present a preliminary measurement of the $t\bar t$ pair production cross section in the collisions of protons and anti-protons at 1.96\~TeV at the Collider Detector at Fermilab (CDF). The measurement uses $t\bar t$ decays into final states which contain one high transverse momentum lepton and multiple jets, where one of the jets is required to be identified as a $b$-jet candidate from the information of the track´s impact parameter resolution using the SVXII Silicon Vertex detector. The performance of the tagging algorithm used in this analysis is also discussed.