Measurement of the mass of the top quark in dilepton final states with the D0 detector

Brandt, Oleg ; U., /Bonn

Fermi National Accelerator Laboratory

关键词: T Quarks Experiment-Hep;    Protons;    Decay;    Standard Model;    Fermilab Tevatron;   

DOI  :  10.2172/897028
RP-ID  :  FERMILAB-MASTERS-2006-03
RP-ID  :  AC02-07CH11359
RP-ID  :  897028

美国|英语

来源: UNT Digital Library

【 摘 要 】

In the Standard Model (SM) the top quark mass is a fundamental parameter. Its precise measurement is important to test the self-consistency of the SM. Additionally, it offers sensitivity to New Physics beyond the Standard Model. In proton anti-proton collisions at a centre-of-mass energy of {radical}s = 1.96 TeV t{bar t} quarks are pair-produced, each decaying into a W boson and a b quark. In the dilepton channel both W bosons decay leptonically. Because of the presence of two neutrinos in the final state the kinematics are underconstrained. A so-called Neutrino Weighting algorithm is used to calculate a weight for the consistency of a hypothesized top quark mass with the event kinematics. To render the problem solvable, the pseudorapidities of the neutrinos are assumed. The Maximum Method, which takes the maximum to the weight distribution as input to infer the top quark mass, is applied to approximately 370 pb{sup -1} of Run-II data, recorded by the D0 experiment at the Tevatron. The e{mu}-channel of the 835 pb{sup -1} dataset is analyzed.