Measurements of $t\bar{t}$ spin correlations in CMS
暂无分享,去创建一个
We present an overview of the measurements of $t\bar{t}$ spin correlations in the CMS Collaboration. We present two analyses both in the dilepton channel using proton-proton collisions at $\sqrt{s}\, =\, 7$ TeV based on an integrated luminosity of 5.0 fb$^{-1}$. The spin correlations and polarization are measured using angular asymmetries. The results are consistent with unpolarized top quarks and Standard Model spin correlation. The second analysis sets a limit on the real part of the top-quark chromo-magnetic dipole moment of $-0.043\, <\, Re({\hat{\mu}}_{t})\, <\, 0.117$ at $95\,%$ confidence level through the measured azimuthal angle difference between the two charged leptons from $t\bar{t}$ production.
[1] V. M. Ghete,et al. Measurements of tt spin correlations and top-quark polarization using dilepton final states in pp collisions at sqrt[s]=7 TeV. , 2013, Physical review letters.
[2] Z. Si,et al. Top quark spin correlations and polarization at the LHC: Standard model predictions and effects of anomalous top chromo moments , 2013, 1305.2066.
[3] Z. Si,et al. Distributions and correlations for top quark pair production and decay at the Tevatron and LHC. , 2010, 1003.3926.