README.md

Reconstruct the $t\bar{t}$ kinematics

TODO

1. Reconstruct the variables:

   • $M_t$

   • $M_{\bar{t}}$

   • $M_{W^+}$

   • $M_{W^-}$

   • Divide all in leptonic/hadronic and particle/antiparticle decays

   • fit a Breit-Wigner for each histogram (this is important to understand the magnitude of the non resonant decay)

   • Do a wider version of the plots to see the tails

2. • Do the same plots for $\eta$ and $p_T$
3. • Create and histogram containing all the possible $q\bar{q}$ couples and fill it with the hadronic W decays

   Optional

   • Multithreaded loop over events (or implement everything using the RDataframes)

Questions

• Why the gluon fusion production (90%) dominate over the quark production (10%)?

  • At the LHC energy the bjorken variable $x=\frac{|q|^2}{2p_{in}^{\mu} q_{\mu} } $ is small and for small X the gluon PDF is much higher than the quark PDF.

    For example, at the Tevatron, the CM energy was 1TeV and ttbar production was mainly from valence quarks

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Info

• Object dictionary: Documentation for mc94X_NANO.root

  

• pdgId:

  

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Observation and doubts