Changes between Initial Version and Version 1 of FAQ-Matching-2


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Timestamp:
03/20/12 16:17:39 (8 years ago)
Author:
trac
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  • FAQ-Matching-2

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     3Yes, you can, the shape of distributions are kept. However the normalization change.
     4In the case you use scalefact and alpsfact in the run_card, this change of scales can be compensated by using the parameters %$PARP(64)$% and %$PARP(72)$%.
     5Let's see this in more details:
     6
     7For ME, the parameters are as follows:
     8   * scalefact multiplies the (linear) factorization scale and
     9      * for non-matched production also the renormalization scale since those are set equal in this case
     10      * for matched production the renormalization scale of QCD vertices that are not considered "extra jet" vertices
     11   * alpsfact multiplies the renormalization scale for extra jets for matched production only.
     12
     13For Pythia, the parameters are:
     14
     15   * For spacelike showers: PARP(64) is factor of %$K_{T}^{2}$% (note squared, so alpsfact=2 corresponds to PARP(64)=4)
     16   * For timelike showers: %$\Lambda_{QCD}$% is given in PARP(72), so this value should be multiplied by 0.5 when alpsfact is 2, and by 2 when alpsfact is 0.5. The default value is 0.25 !GeV.
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     18-- Main.SimonDeVisscher - 02 Mar 2009
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