resonacnes_params.rst

Resonances Parameters

This section is about how do the Resonances.yml work.

From Resonacces.yml to the real model, there will be following steps.

1. loaded by config.yml, it is will be combined the defination in config.yml particle parts.

   For examples, config.yml have

   particle:
      $include: Resonances.yml
      Psi4040:
         float: mg
   

   then Resonances.yml item

   Psi4040:
      J: 1
      float: m
   

   will become {"Psi4040": {"J": 1, "float": "mg"}}

2. replace some alias, (m0 -> mass, g0 -> width, ...)

3. If it is used in decay chain, then create Particle object.

   The particle class is cls = get_particle_model(item["model"]), and the object is cls(**item).

   All parameters wull be stored in config.particle_property[name].

All aviable parameters can be devied into the flowowing 3 sets.

Common Parameters

Parameters defined in ~tf_pwa.particle.BaseParticle are common parameters including spin, parity, mass and width.

name	default value	comment
J	0	spin, int or half-integral
P	-1	P-parity, +1 or -1
C	None	C-Parity, +1 or -1
mass	None	mass, float, it is always required because of the calcultion of q_0
width	None	width, float
spins	None	possible spin projections,`[-J, ..., J]`, list

Model Parameters

Parameters defined in the real model. :doc:`particle_model`

There are many parameters defined by the user, the those parameters will be pass to model class, such as the paramthers for __init__(self, **kwargs) method.

For examples, the default model (BWR, ~tf_pwa.particle.BaseParticle) have following parameters:

name	default value	comment
running_width	True	if using running width, bool
bw_l	None, auto deteminated	running width angular momentum, int

Other Parameters

There are also some other parameters which is used to control the program running.

For examples, simple constrains, the following parameters are using by ~tf_pwa.config_loader.ConfigLoader as constrains.

name	default value	comment
mass_min, mass_max	None	mass range
width_min, width_max	None	width range
float	[]	float paramsters list

Another examples are parameters to build decay chain for particle R.

name	default value	comment
decay_params	{}	parameters pass to Decay which R decay
production_params	{}	parameters pass to Decay which produce R
model	default	Particle model for R

There are also other common used parameters.

name	default value	comment
display	None	control plot legend with latex string, string