The top quark as a calibration tool at the LHC

摘要

Due to the large top quark pair production cross-section and therelatively low background expected at the LHC, tt events can be used for calibrationat ATLAS and CMS. Assuming the Standard Model prediction BR(t→bW) =1,the heavy flavour content of tt events is well predicted, allowing the calibrationand efficiency measurement of b-tagging algorithms directly from the data witha precision of about 5%. The light (and b-) parton jet energy scale can also beextracted from tt events at the 1% level using W (and top) hadronic decays.