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GR@PPA 2.7 event generator for $pp$/$p\bar{p}$ collisions

S. Tsuno·T. Kaneko·Y. Kurihara·S. Odaka·K. Kato
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Abstract

The GR@PPA event generator has been updated to version 2.7. This distribution provides event generators for $V$ ($W$ or $Z$) + jets ($\leq$ 4 jets), $VV$ + jets ($\leq$ 2 jets) and QCD multi-jet ($\leq$ 4 jets) production processes at $pp$ and $p\bar{p}$ collisions, in addition to the four bottom quark productions implemented in our previous work (GR@PPA\_4b). Also included are the top-pair and top-pair + jet production processes, where the correlation between the decay products are fully reproduced at the tree level. Namely, processes up to seven-body productions can be simulated, based on ordinary Feynman diagram calculations at the tree level. In this version, the GR@PPA framework and the process dependent matrix-element routines are separately provided. This makes it easier to add further new processes, and allows users to make a choice of processes to implement. This version also has several new features to handle complicated multi-body production processes. A systematic way to combine many subprocesses to a single base-subprocess has been introduced, and a new method has been adopted to calculate the color factors of complicated QCD processes. They speed up the calculation significantly.

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S. Tsuno, T. Kaneko, Y. Kurihara, S. Odaka, K. Kato. 2006-02-23. GR@PPA 2.7 event generator for $pp$/$p\bar{p}$ collisions. https://doi.org/10.1016/j.cpc.2006.07.011

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