Matrix Element Kinematic Discriminant (MEKD)

Framework for using squared matrix elements for event classification.

get with

$ git clone https://github.com/odysei/MEKD

Build (standalone)

Bash procedure follows below.

• Setup the environment:

  $ . scripts/setup_flags.sh

  $ . scripts/add_local_lib.sh

• Buil the library: libMEKD.so

  $ make -j N

Directory structure

• bin:

• data:

• doc:

• interface:

• lib:

• scripts:

• src:

• test:

• utils:

Usage

Instantiation

The MEKD class is instantiated by providing a vector of process descriptions, like the following:

vector<process_description> my_processes;

...

MEKD my_MEs(my_processes);

Evaluation

Prepare your input, see input and input_c (MEKD_input.h), and your output vector (don't forget to reserve size), and run eval_MEs, like this:

input my_input;

vector my_results;

...

eval_MEs(my_input, my_results);

If you vary couplings via the code, the parameter file values will be overriden during a runtime. In other words, use one or the other method, but don't mix as you will run into an unwanted behavior.

Some details on evaluation

Internal computation sequence is the following:

HEF_MEKD (4 leptons) for v2 and earlier:

1. eval_MEs(...) (user runs this)
2. ME_runners[i]->evaluate(...)
3. Run_ME_Configurator_HYPOTHESIS(...) (turn on/off couplings)
4. Run_ME_Configurator_SPIN(...) (generic coupling mixer)
5. Run_ME_Dispatcher_SPIN(...) (find and dispatch correct ME)
6. Run_MEs_Evaluator_Initial_State_TYPE(..., ME)

v3:

1. eval_MEs(...) (user runs this)
2. ME_runners[i]->evaluate(...)
3. template<> evaluate_PROCESS(...)
4. template<> Configurator_Spin0(...) (prepares Parameters_X: couplings, mass, etc.)
5. template<> ME_Evaluator_IS_XX(...) (evaluates provided ME)

Formatting

The following code style(s) is(are) used:

• For C/C++: Linux Kernel Style, see https://www.kernel.org/doc/Documentation/CodingStyle

• For Python: PEP, see https://www.python.org/dev/peps/pep-0008/

• RUN clang-format: some automatization for C++ is available through clang-format. Use it! Run:

  $ clang-format -style=file -i *.h

  $ clang-format -style=file -i *.cc

  $ clang-format -style=file -i *.cpp

to update all files in a current directory.

Notes

Inherently from MadGraph code has some of its parameters as statics, which is, in general, dangerous. Will likely have some problems if running multithreaded or/with several objects with "similar" calculations, i.e., unwanted xtalk.