Amplitude modeling — decaylanguage.modeling

A class representing a set of decays. Can be subclassed to provide custom converters.

class decaylanguage.modeling.amplitudechain.LS(*values)

Line shapes supported (currently)

RBW = 0

GSpline = 1

kMatrix = 2

FOCUS = 3

class decaylanguage.modeling.amplitudechain.AmplitudeChain(particle, daughters=NOTHING, lineshape=None, spinfactor=None, amp=1 + 0j, err=0j, fix=True, name=None)

This is a chain of decays (a “line”)

lineshape

spinfactor

amp

err

fix

name

all_particles: ClassVar[Particle] = {}

final_particles: ClassVar[Particle] = {}

cartesian = False

classmethod from_matched_line(mat)

This operates on an already-matched line.

Parameters:

mat – The groupdict output of a match

Returns:

A new amplitude chain instance

expand_lines(linelist)

Take a DecayTree -> list of DecayTrees with each dead-end daughter expanded to every possible combination. (recursive)

property ls_enum

property full_amp

L_range(conserveParity=False)

property L

classmethod read_ampgen(filename=None, text=None, grammar=None, parser='lalr', **kargs)

Read in an ampgen file

Parameters:

• filename – Filename to read

• text – Text to read (use instead of filename)

Returns:

array of AmplitudeChains, parameters, constants, event type

decaylanguage.modeling.ampgentransform.get_from_parser(parser, key)

class decaylanguage.modeling.ampgentransform.AmpGenTransformer(visit_tokens=True)

Parameters:

visit_tokens (bool)

constant(lines)

event_type(lines)

checkfixed(lines)

variable(lines)

cplx_decay_line(lines)

decay(lines)

This is a GooFit adaptor for amplitude chain.

class decaylanguage.modeling.goofit.SF_4Body(*values)

DtoPP1_PtoSP2_StoP3P4 = 0

DtoPP1_PtoVP2_VtoP3P4 = 1

DtoV1V2_V1toP1P2_V2toP3P4_S = 2

DtoV1V2_V1toP1P2_V2toP3P4_P = 3

DtoV1V2_V1toP1P2_V2toP3P4_D = 4

DtoAP1_AtoVP2_VtoP3P4 = 5

DtoAP1_AtoVP2Dwave_VtoP3P4 = 6

DtoVS_VtoP1P2_StoP3P4 = 7

DtoV1P1_V1toV2P2_V2toP3P4 = 8

DtoAP1_AtoSP2_StoP3P4 = 9

DtoTP1_TtoVP2_VtoP3P4 = 10

FF_12_34_L1 = 11

FF_12_34_L2 = 12

FF_123_4_L1 = 13

FF_123_4_L2 = 14

ONE = 15

decaylanguage.modeling.goofit.sprint(stype)

class decaylanguage.modeling.goofit.DecayStructure(*values)

FF_12_34 = 0

FF_1_2_34 = 1

class decaylanguage.modeling.goofit.GooFitChain(particle, daughters=NOTHING, lineshape=None, spinfactor=None, amp=1 + 0j, err=0j, fix=True, name=None)

Class to read an AmpGen options file and return GooFit C++ code.

pars: DataFrame = None

consts: DataFrame = None

classmethod make_intro(all_states)

Write out definitions of constant variables and vectors to hold intermediate values.

property decay_structure

Determine if decay proceeds via two resonances or cascade decay.

property formfactor

Return form factor based on relative angular momentum L.

spindetails()

Return string with spin structure.

property spinfactors

Check if the spin structure is known and return it together with the form factor.

classmethod make_pars()

Write out the parameters used in the amplitudes.

make_lineshape(structure, masses)

Write out the line shapes. Each kind of line shape is treated separately.

make_spinfactor(final_states)

Write out the spin factor and push it to a vector.

make_linefactor(final_states)

Write out the line shape and push it to a vector.

make_amplitude(final_states)

Write out the amplitude and push it to a vector.

to_goofit(final_states)

Write the vectors with the spin factors, line shapes and amplitudes.

classmethod read_ampgen(*args, **kargs)

Read in an AmpGen file.

Returns:

Array of AmplitudeChains, event type.

class decaylanguage.modeling.goofit.GooFitPyChain(particle, daughters=NOTHING, lineshape=None, spinfactor=None, amp=1 + 0j, err=0j, fix=True, name=None)

Class to read an AmpGen options file and return a GooFit Python script.

pars: DataFrame = None

consts: DataFrame = None

classmethod make_intro(all_states)

Write out definitions of constant variables and lists to hold intermediate values.

property decay_structure

Determine if the decay proceeds via two resonances or a cascade decay.

property formfactor

Return the form factor based on relative angular momentum L.

spindetails()

Return string with spin structure.

property spinfactors

Check if the spin structure is known and return it together with the form factor.

classmethod make_pars()

Write out the parameters used in the amplitudes.

make_lineshape(structure, masses)

Write out the line shapes. Each kind of line shape is treated separately.

make_spinfactor(final_states)

Write out the spin factor and push it to a vector.

make_linefactor(final_states)

Write out the line shape and push it to a vector.

make_amplitude(final_states)

Write out the amplitude and push it to a vector.

to_goofit(final_states)

Write the lists with the spin factors, line shapes and amplitudes.

classmethod read_ampgen(*args, **kargs)

Read in the AmpGen file.

Returns:

Array of AmplitudeChains, event type.

A general base class representing decays.

class decaylanguage.modeling.decay.ModelDecay(particle, daughters=NOTHING, name=None)

This describes a decay very generally, with search and print features. Subclassed for further usage.

particle

daughters

name

is_vertex()

is_strong()

property vertexes

property structure

The structure of the decay chain, simplified to only final state particles

list_structure(final_states)

The structure in the form [(0,1,2,3)], where the dual-list is used for permutations for bose symmatrization. So for final_states=[a,b,c,c], [a,c,[c,b]] would be: [(0,2,3,1),(0,3,2,1)]