Changes between Version 8 and Version 9 of ComplexMassScheme


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Timestamp:
Aug 13, 2015, 2:03:18 AM (9 years ago)
Author:
Valentin Hirschi
Comment:

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  • ComplexMassScheme

    v8 v9  
    3636The LO CMS test is mostly trivial, but it can be useful to investigate the expected sensitivity on the CMS implementation of the corresponding NLO process.
    3737
    38 Finally, the following options are available (presented along with their default value)
     38Finally, the following options are available and we detail their usage in the next sections.
    3939
    4040== Basic options ==
     
    5656   * Example: --energy=2000.0
    5757
     58 {{{--lambdaCMS=(1.0e-6,5)}}}::
     59    Sets what values of the scaling parameter $\lambda$ must be used for the test. This option can either be a tuple '(min_val, points_per_decade)', a float 'min_val' or a python list. The float 'min_val' is the minimal value of $\lambda$ to probe and $points_per_decade$ is the number points one should spread uniformly in each decade (i.e. interval [$10^{-i+1},10^-i$]. Notice that the list must always contain the value 1.
     60   * Example: --lambdaCMS=(1.0e-2,5)
     61 With this option, the list of $\lambda$ values used will be: [1, 0.8, 0.6, 0.4, 0.2, 0.1, 0.08, 0.06, 0.04, 0.02, 0.01]
     62   * Example: --lambdaCMS=[float('1.0e-%d'%exp)\ for\ exp\ in\ range(8)]
     63 With this option, the list will be evaluated and the return list will be used, i.e.: [1.0, 0.1, 0.01, 0.001, 0.0001, 1e-05, 1e-06, 1e-07]. Notice that spaces must be escaped and this options should be placed last for parsing reasons.
     64
     65 {{{--show_plot=True}}}::
     66    Allow to turn off the matplotlib generation and only report the outcome of the numerical check. Turning it off also removes the progress_bar display during the check
     67   * Example: --show_plot=False
     68
     69 {{{--recompute_width=auto}}}::
     70    Decides how to compute the leading-order accurate width necessary for the test to pass. Four possible values 'never', 'first_time', 'always' or 'auto'. 'never' means that the width for $\lambda=1$ will be taken from the value in the default param_card .dat and the widths for subsequent smaller values of $\lambda$ will be computed via a simple scaling law. 'first_time' means that the widths will be computed (numerically or analytically if the model has a decay module) with MadWidth' for $\lambda=1$ and scaled down for lower $\lambda$ values. 'always' means that the widths will be recomputed for all $\lambda$ values (this mode is only to be used for checking the width computation). Finally the default value 'auto' will be interpreted as 'never' for an LO test where LO-accurate width aren't necessary in the offshell region and 'first_time' if the check is NLO.
     71   * Example: --recompute_width=never
     72
    5873== Special option ==
    5974
     
    6176    This option must be used without any process definition. It is intended to specify the path of pickle files storing the results of previous results to be re-analyzed and replotted. A common usage of this option is:
    6277   * Example: check cms --analyze=my_default_run.pkl,increased_widths.pkl(Increased_widths),logs_modified.pkl(Inverted_logs),seed_668.pkl(Different_seed)
    63    
    64     This will reanalyze the data in my_default_run.pkl and plot them while also including the curves from the list of pickle paths following the first one. The name in parenthesis will serve as the legend (underscores will be replaced by spaces)
     78 This will reanalyze the data in my_default_run.pkl and plot them while also including the curves from the list of pickle paths following the first one. The name in parenthesis will serve as the legend (underscores will be replaced by spaces)
    6579
    6680== More technical options ==
     
    6983    This is one of the most complicated options and it contains two parts separated by a comma. The first part lists the coupling orders which take part in the expansion. The second part lists how to scale the corresponding parameter which drive the expansion. These must be external parameters present in the param_card. The value 'lambdaCMS' is a special tag which refers to the current value of the scaling parameter $\lambda$ being considered. Notice that these replacement rules must be of the form <ext_param_name>->f(<ext_param_name>,lambdaCMS) where f is some function following python syntax. The default value start from fixed values 10.0 and 0.1 for $\lambda=1$, but it is possible to specify the original value of the parameter in the card like this 'aewm1->aewm1/lambdaCMS' in which case the base value of the external parameter aewm1 will be the one in the original param_card.dat. You should not need to change this default unless you are testing a new physics model with an extended gauge sector (in which case the modification could look like the example below).
    7084   * Example: --cms=QED&QCD&NP,aewm1->10.0/lambdaCMS&as->0.1*lambdaCMS&newExpansionParameter->newExpansionParameter*lambdaCMS
     85
     86 {{{--diff_lambda_power=1}}}::
     87    This controls by which power to divide the difference term $\Lambda$. The default is of course equal to one so as to test $\kappa^{\text{NLO|LO}}_0=0$ but at LO it is sometimes interesting to divide $\Delta$ by $\lambda^2$ so a to see if $\kappa^{\text{LO}}_1$ is vanishing as well. This is expected to be the case for all $2\rightarrow2$ processes (i.e. the plot of $\Delta/\lambda^2$ has a constant asymptot as well, so that $\kappa^{\text{LO}}_1=0$). For such processes, the higher order contribution $\kappa^{\text{NLO}}_0$ is zero by construction and the test is not sensitive to the CMS implementation
     88   * Example: check cms u d~ > e+ ve --diff_lambda_power=2
     89
     90 {{{ --loop_filter=None}}}:
     91    Allows to specify a conditional expression to impose a requirement on the loop diagrams to be kept. This expression can only be an pyton expression of involving the following variables : 'n', the number of loop propagators; 'id' the loop diagram number as it can be read in the postscript generated with the command display diagrams; 'loop_pdgs' the list of absolute values of the PDG of the particles running in the loop; 'loop_masses' and 'struct_masses' the list of the parameter names of the masses running in the loop and the masses of the particles directly attached to the loop.
     92   * Example: --loop_filter='n>3'
     93 Selects only box diagrams and above.
     94   * Example: --loop_filter='n<4 and 6 in loop_pdgs and 3<=id<=7'
     95Selects only triangle loop or smaller, with at least a top running in the loop and whose ID is in the range [3,7].