Changes between Version 52 and Version 53 of Reweight


Ignore:
Timestamp:
Jul 4, 2016, 12:19:31 PM (8 years ago)
Author:
Olivier Mattelaer
Comment:

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  • Reweight

    v52 v53  
    66 The method works only if both the original and the new hypothesis give non-negligible contributions to the same parts of the phase-space.
    77 
    8  We support four types of reweightings, one for Leading Order (LO) samples, and three for Next-to-Leading Order (NLO) samples. One of them is NLO accurate (dubbed NLO re-weighting) and two are approximate using LO method (LO/Kamikaze Reweighting and Loop Improved)
     8 We support four types of reweightings, one for Leading Order (LO) samples, and three for Next-to-Leading Order (NLO) samples. One of them is NLO accurate (dubbed NLO re-weighting) and two are approximate using LO method (LO like Reweighting and Loop Improved)
    99
    1010 '''Leading Order'''[[BR]][[BR]]
    … …  
    1919 where $\bar R$ is the average of the ratio of the matrix-element, $\Delta R$ the associated variance. $\mathcal{O}_{old/new}$ is the value of the observable under consideration for the associated hypothesis and $\Delta\mathcal{O}_{old/new}$ the associated variance.
    2020
    21  '''Kamikaze Reweighting'''[[BR]][[BR]]
     21 '''LO like Reweighting'''[[BR]][[BR]]
    2222 This corresponds to a LO-type reweighting. Both soft and hard events are reweighted according to the tree-level matrix elements associated with the suitable number of final-state particles i.e.,
    2323        $$W^S_{new} = |M^{new}_{born}|^2 /|M^{old}_{born}|^2 * W^S_{old} $$
    … …  
    6565 with the final weight computed by recombining these weights according to the prescription given in the NLO descriptions.
    6666
    67  This method is mainly intended for case where the virtual can not be computed as in the case where the Born of the new method is a loop-induced production (justifying the name). As the LO/kamikaze re-weighting it is not NLO accurate. One can argue that it should be more accurate than the kamikaze method but this statement was never proven anywhere so far.
     67 This method is mainly intended for case where the virtual can not be computed as in the case where the Born of the new method is a loop-induced production (justifying the name). As the LO like re-weighting it is not NLO accurate. One can argue that it should be more accurate than the LO like method but this statement was never proven anywhere so far.
    6868
    6969 '''This method will be released in a future version of MadGraph5_aMC@NLO''' and can currently be provided on request. Since it is based on a dedicated decomposition, the NLO sample must be generated in a specific way for the Les Houches event file to contain the necessary information (see below).
    … …  
    140140If you want to perform the NLO-accurate reweighting, you might want to have the parameter "store_rwgt_info" of the run_card on True.
    141141Note that this parameter will be automatically switched to True if you request at the time of the generation a NLO accurate re-weighting (or the loop-improved one).
    142 You are force to set this parameter manually if you want to perform such re-weighting independently of the event generation (otherwise only the kamikaze reweighting will be available).
     142You are force to set this parameter manually if you want to perform such re-weighting independently of the event generation (otherwise only the LO like reweighting will be available).
    143143
    144144
    … …  
    175175   5. '''change helicity <True|False>''': performs reweighting for the given helicity (True --default--) or carry out the sum over helicity (False).
    176176   6. '''change rwgt_dir <PATH>''': changes directory where the computation is performed. This can be used to avoid to recreate/recompile the fortran executable if pointing to a previously existing directory.
    177    7. '''change mode <LO|NLO|NLO_tree|LO+NLO>''': For LO sample, this line is always ignored. For NLO samples this select the reweighting mode "LO" for the kamikaze, "NLO" for the NLO accurate method, "NLO_tree" for the loop-improved and "LO+NLO" to run simultaneously the kamikaze and NLO method.
     177   7. '''change mode <LO|NLO|NLO_tree|LO+NLO>''': For LO sample, this line is always ignored. For NLO samples this select the reweighting mode "LO" for the LO like reweighting method, "NLO" for the NLO accurate method, "NLO_tree" for the loop-improved and "LO+NLO" to run simultaneously the LO like and NLO method.
    178178
    179179 2. '''Benchmark definition''':[[BR]]
    … …  
    231231   set Dim6 5 0
    232232}}}
    233  === Kamikaze reweighting
     233 === LO like reweighting
    234234 {{{
    235235 change mode LO