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Spin Correlations in tt Events from pp Collisions pp 93–120Cite as

Event Selection and Reconstruction

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Part of the book series: Springer Theses ((Springer Theses))

Abstract

With the \(\ell +\text {jets}\) channel as the \(t\bar{t}\) final state under study, advantages and challenges come along. Every event provides the necessary information for full reconstruction of all the objects of interest. The dilepton channel suffers from the ambiguity of two undetected neutrinos, making it hard to reconstruct both of them correctly. In contrast, using assumptions such as the masses of the top quark and the W boson, the whole \(t\bar{t}\) event can be reconstructed in the \(\ell +\text {jets}\) channel.

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Notes

  1. 1.

    A trigger prescale of p randomly drops a fraction \((1-\frac{1}{p})\) of events that had passed the trigger chain to reduce the data rate. Unprescaled triggers have \(p = 1\), so no events are dropped.

  2. 2.

    \(\textit{p}_\mathrm{{T}}^{\mu } > 20 \mathrm{GeV}\) and \(E_\mathrm{T}^{e} > 25 \mathrm{GeV}\).

  3. 3.

    Technically, the negative logarithm of the likelihood is minimized.

  4. 4.

    Normalized with respect to all permutations.

  5. 5.

    The mistag rate \(\varepsilon _l\) is the probability to tag a non-b-jet as b-jet.

  6. 6.

    Only the parameterization type is kept fixed, not the numerical parameter values.

  7. 7.

    In the latter case the quark jets could be separated by the \(b\)-tag weight.

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Authors and Affiliations

  1. II. Physikalisches Institut, Georg-August-Universität Göttingen, Göttingen, Germany

    Boris Lemmer

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  1. Boris Lemmer
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Correspondence to Boris Lemmer .

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Lemmer, B. (2015). Event Selection and Reconstruction. In: Spin Correlations in tt Events from pp Collisions. Springer Theses. Springer, Cham. https://doi.org/10.1007/978-3-319-18932-1_5

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