Measurement of the mass difference between top and anti-top quarks in pp collisions at (√s)=7 TeV using the ATLAS detector

ATLAS COLLABORATION, G. AAD, F. MONTICELLI, ET AL

PHYSICS LETTERS B

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2013 vol. 231 p. 1 - 23

0370-2693

A measurement of the mass difference between top and anti-top quarks is presented. In a√4.7 fb−1 data sample of proton?proton collisions at s = 7 TeV recorded with the ATLAS detec- ̄tor at the LHC, events consistent with tt production and decay into a single charged lepton finalstate are reconstructed. For each event, the mass difference between the top and anti-top quarkcandidate is calculated. A two b-tag requirement is used in order to reduce the background con-tribution. A maximum likelihood fit to these per-event mass differences yields ∆m ≡ mt − mt = ̄0.67 ± 0.61(stat)±0.41(syst) GeV, consistent with CPT invariance.