Top cross-section: manpower wanted!

These topics have the potential to become publications that will provide important results on top quark physics. They are either uncovered or covered thinly and they could use some help. If you are interested in any topic, please contact the top cross-section conveners (Mark Owen and Francesco Spanò)

Resolved differential cross-section at 8 TeV

• See 7 TeV activities.
• Many old and new distributions can be considered.
  • Standard distributions from 7 TeV likes top pT, ttbar-system mass, pT, and rapidity, dR, deta or dphi between the two top quarks.
  • A number of new distribution providing differential measurements relative to the top system: dsigma(extra jet)/dX where X could be dphi(top, jet), deta(top, jet), pT(top) etc.
  • Finally one can consider the differential distributions of the final objects in the top decay products: lepton pt, highest pt jet, b-jet etc.
• Variables can be defined at particle level (pseudo-top) in a fiducial region or in the full phase space at parton level.
• Need to cover both lepton +jets and dilepton channels.
• See more ideas of differential top measurements in pages 26-27 and 28 here.
• A possibility, joint with the top-mass group: measurements of top cross-section binned in top mass (or even 2d?). Could have similarities to the one released by CMS, but there are a lot of new directions that this could be taken (for example, probing sensitivity to top width).

Properties of jets at 8 TeV (also important as backgrounds for new physics):

• Jet multiplicity measurements (such as the 7 TeV results in the dilepton and lepton plus jets channels and the jet veto measurement).
• Differential jet pT measurements. Some work is being done in this direction at 7 TeV but none at 8 TeV.
• Jet flavor measurements for radiated jets (any of b vs c vs light-quark vs light gluon vs double-bb). Example statistically-limited measurement at 7 TeV.

Interesting analysis on Lorentz Invariance of ttbar production has lost its manpower.

• See overview presentation here.

Precision cross-section measurements, especially in the lepton+jets channel

• Help in taking over Cross-section + Rb measurement at 7 TeV. Link.
• All-hadronic cross-section at 8 TeV: uncovered
• Tau+lepton cross-section at 8 TeV: uncovered
• Tau+ jets cross section at 8 TeV: uncovered