Changes between Version 7 and Version 8 of ComplexMassScheme

Timestamp:

Aug 13, 2015, 1:05:34 AM (9 years ago)

Author:

Valentin Hirschi

Comment:

--

ComplexMassScheme

@@ -23 +23 @@
 [[Image(gg_epvemumvmxbbx.jpg,500)]] [[Image(gg_epvemumvmxbbx_inverted_logs.jpg,500)]]
 
-In the upper inset, we clearly see the finite width effects for large values of $\lambda$. These become progressively smaller and indiscernible below $10^{-3}$. When dividing this difference by lambda, as done in the lower inset, we only see a mild deviation with respect to a constant. Changing the LO width used for the test by as little as 0.1 % already yields a larger $\kappa^{\text{NLO}}_0$ than the residual one stemming from numerical inaccuracies. Changing the analytical continuation of the logarithms of the UV wavefunctions counterterms to make them incorrect would yield an asymptot in the $\Delta^{NLO}/\lambda$ plot of the order of thousands, clearly assessing the sensitivity of the test towards any incorrect CMS implementation at NLO.
+In the upper inset, we clearly see the finite width effects for large values of $\lambda$. These become progressively smaller and indiscernible below $10^{-3}$. When dividing this difference by lambda, as done in the lower inset, we only see a mild deviation with respect to a constant. Changing the LO width used for the test by as little as 0.1 % already yields a larger $\kappa^{\text{NLO}}_0$ than the residual one stemming from numerical inaccuracies. The figure on the left shows that incorrectly setting the analytical continuation of UV wavefunctions counterterms logarithms yields an asymptotic value of several thousands in the $\Delta^{NLO}/\lambda$ plot. This clearly establishes the sensitivity of the test towards any incorrect CMS implementation at NLO.
 
-We now focus on the description of the command, whose main syntax is
+We now focus on the description of the command for this check, whose main syntax is
 
 {{{ MG5_aMC> check cms [-reuse] <process_definition> <options> }}}
 
+First, the '-reuse' following 'cms' specifies that you want to reuse relevant information existing from previous runs. This includes potentially reusing the fortran output of the NLO matrix element if the same process was run before with the 'cms check' command. Also, if a name was given to this run (see option '--name' further) and the corresponding saved result python pickled file exists on disk, this run will be skipped and the result recycled from the pickle file.
+When '-reuse' is not specified, the test always restarts from scratch. In general, it is recommended to always use '-reuse'.
 
+The <process_definition> which follows can be any process following the MG5 syntax. If this process is LO, the test will be adapted to test $\kappa^{\text{LO}}_0$ and the matrix element will be generated an evaluated dynamically directly in python.
+If the process definition is at NLO, then the test will test $\kappa^{\text{NLO}}_0$ and the output will be done in fortran on disk, compiled and the corresponding standalone 'check' executable steered by MG5_aMC.
+The 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.
 
+Finally, the following options are available (presented along with their default value)
 
-=== Basic Syntax Rules ===
+== Basic options ==
 
-   * Use a ">" to separate the initial state particle(s) from the final state ones.
+ {{{--name=auto}}}::
+   This will serve as the base_name for the fortran output folder for the loop matrix element and for the pickle files storing the results generated. The default 'auto' tries to smartly automatically assign one, but it is recommended to specify your own.
+   * Example: --name=fully_decayed_ttx
 
-   * Initial state can be one (decay) or two (scattering) particles.
+ {{{--seed=666}}}::
+   Changes the seed for the generation of the offshell kinematic configuration, allowing for varying the config. The value '-1' sets it so that it is different for every run.
+   * Example: --seed=667
 
-   * Use " x x > [[span(z,style=color: #990099;)]] > y y y " form to require particle [[span(z,style=color: #990099;)]] to appear in a s-channel intermediate state (not recommended due to gauge invariance).
+ {{{--offshellness=10.0}}}::
+   Sets what is the minimum requirement of offshellness for each resonance that the kinematic configuration must satisfay. The default offshellness $\chi$ of 10 is such that the momentum of each resonance must satisfy $p^2>(\chi+1)M$. The offshellness can be negative too, but always strictly larger than -1. Notice that when the offshellness required is negative, it is not guaranteed that MG5_aMC will find a valid kinematic configuration if external states are massive. Finally, notice that the phase kinematic configuration chosen satisfies extra requirement of isolations and hardness in terms of a minimal pt cut and $\delta$R between all external legs.
+   * Example: --offshellness=-0.7
 
-   * Use " x x > y y y $ [[span(z,style=color: #990099;)]]" form to forbid particle [[span(z,style=color: #990099;)]] from appearing in a s-channel intermediate state (not recommended due to gauge invariance).
+ {{{--energy=5000.0}}}::
+    Sets the target energy for the kinematic configuration to build. Notice that this energy will be automatically changed with a warning depending on its consistency with the offshellness required.
+   * Example: --energy=2000.0
 
-   * Use " x x > y y y / [[span(z,style=color: #990099;)]]" form to exclude particle [[span(z,style=color: #990099;)]] to appear as internal particle in any diagram.
+== Special option ==
 
-   * Use comma to specify decay chains. For instance "x x > Z W, Z >y y, W > k k" means "x x > Z W" where Z then decays to yy and W to kk.
-   * Coupling orders are automatically detected to generate the leading order processes. To explicitly specify coupling orders, add them after the process on the same line:[[br]]x x > y y y / z QCD=0[[br]]x x > Z W QED=2, Z > y y, W > k k[[br]]Note that if a coupling order is omitted, it defaults to infinity (or, for restricted couplings such as HIG in the HEFT model, to the restricted value).
-   * Use the multi-label "p" to indicate a proton or an anti-proton.[[br]] The symbol "p~" does not exist. In fact the type of initial state (pp or ppbar or parton-parton fixed energy) is specified later, during the run, in the run_card.dat.[[br]]The multi-lable "j" suggests a final-state jet.
-   * Note that the syntax for MadGraph 5 differs slightly from previous versions: a space (" ") is required between particle names, and the decay chain syntax has been upgraded to a more powerful syntax which allows better control of the different processes.
+ {{{--analyze=None}}}::
+    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:
+   * Example: check cms --analyze=my_default_run.pkl,increased_widths.pkl(Increased_widths),logs_modified.pkl(Inverted_logs),seed_668.pkl(Different_seed)
+    
+    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)
 
-=== Process Examples ===
+== More technical options ==
 
-|| '''PROCESS''' || '''Sample Diagram''' || '''Notes''' ||
-
-[[Image(CMS_result.jpg,629)]]
+ {{{--cms=QED&QCD,aewm1->10.0/lambdaCMS&as->0.1*lambdaCMS}}}::
+    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).
+   * Example: --cms=QED&QCD&NP,aewm1->10.0/lambdaCMS&as->0.1*lambdaCMS&newExpansionParameter->newExpansionParameter*lambdaCMS