object_library.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
 
 
 
import cmath
import re
 
 
class UFOError(Exception):
 
    """Exception raised if when inconsistencies are detected in the UFO model."""
 
    pass
 
 
class UFOBaseClass(object):
 
    """The class from which all FeynRules classes are derived."""
 
    require_args = []
 
    def __init__(self, *args, **options):
        assert len(self.require_args) == len(args)
 
        for (i, name) in enumerate(self.require_args):
            setattr(self, name, args[i])
 
        for (option, value) in options.items():
            setattr(self, option, value)
 
    def get(self, name):
        return getattr(self, name)
 
    def set(self, name, value):
        setattr(self, name, value)
 
    def get_all(self):
        """Return a dictionary containing all the information of the object"""
 
        return self.__dict__
 
    def __str__(self):
        return self.name
 
    def nice_string(self):
        """ return string with the full information """
 
        return '\n'.join(['%s \t: %s' % (name, value) for (name, value) in
                         self.__dict__.items()])
 
    def __repr__(self):
        replacements = [
            ('+', '__plus__'),
            ('-', '__minus__'),
            ('@', '__at__'),
            ('!', '__exclam__'),
            ('?', '__quest__'),
            ('*', '__star__'),
            ('~', '__tilde__'),
            ]
        text = self.name
        for (orig, sub) in replacements:
            text = text.replace(orig, sub)
        return text
 
 
all_particles = []
 
 
class Particle(UFOBaseClass):
 
    """A standard Particle"""
 
    require_args = [
        'pdg_code',
        'name',
        'antiname',
        'spin',
        'color',
        'mass',
        'width',
        'texname',
        'antitexname',
        'charge',
        ]
 
    require_args_all = [
        'pdg_code',
        'name',
        'antiname',
        'spin',
        'color',
        'mass',
        'width',
        'texname',
        'antitexname',
        'counterterm',
        'charge',
        'line',
        'propagating',
        'goldstoneboson',
        'propagator',
        ]
 
    def __init__(
        self,
        pdg_code,
        name,
        antiname,
        spin,
        color,
        mass,
        width,
        texname,
        antitexname,
        charge,
        line=None,
        propagating=True,
        counterterm=None,
        goldstoneboson=False,
        propagator=None,
        **options
        ):
 
        args = (
            pdg_code,
            name,
            antiname,
            spin,
            color,
            mass,
            width,
            texname,
            antitexname,
            float(charge),
            )
 
        UFOBaseClass.__init__(self, *args, **options)
 
        global all_particles
        all_particles.append(self)
 
        self.propagating = propagating
        self.goldstoneboson = goldstoneboson
 
        self.selfconjugate = name == antiname
        if not line:
            self.line = self.find_line_type()
        else:
            self.line = line
 
        if propagator:
            if isinstance(propagator, dict):
                self.propagator = propagator
            else:
                self.propagator = {0: propagator, 1: propagator}
 
    def find_line_type(self):
        """ find how we draw a line if not defined
        valid output: dashed/straight/wavy/curly/double/swavy/scurly
        """
 
        spin = self.spin
        color = self.color
 
        # use default
        if spin == 1:
            return 'dashed'
        elif spin == 2:
            if not self.selfconjugate:
                return 'straight'
            elif color == 1:
                return 'swavy'
            else:
                return 'scurly'
        elif spin == 3:
            if color == 1:
                return 'wavy'
            else:
 
                return 'curly'
        elif spin == 5:
            return 'double'
        elif spin == -1:
            return 'dotted'
        else:
            return 'dashed'  # not supported yet
 
    def anti(self):
        if self.selfconjugate:
            raise Exception('%s has no anti particle.' % self.name)
        outdic = {}
        for (k, v) in self.__dict__.iteritems():
            if k not in self.require_args_all:
                outdic[k] = -v
        if self.color in [1, 8]:
            newcolor = self.color
        else:
            newcolor = -self.color
 
        return Particle(
            -self.pdg_code,
            self.antiname,
            self.name,
            self.spin,
            newcolor,
            self.mass,
            self.width,
            self.antitexname,
            self.texname,
            -self.charge,
            self.line,
            self.propagating,
            self.goldstoneboson,
            **outdic
            )
 
 
all_parameters = []
 
 
class Parameter(UFOBaseClass):
 
    require_args = ['name', 'nature', 'type', 'value', 'texname']
 
    def __init__(
        self,
        name,
        nature,
        type,
        value,
        texname,
        lhablock=None,
        lhacode=None,
        ):
 
        args = (name, nature, type, value, texname)
 
        UFOBaseClass.__init__(self, *args)
 
        args = (name, nature, type, value, texname)
 
        global all_parameters
        all_parameters.append(self)
 
        if (lhablock is None or lhacode is None) and nature == 'external':
            raise Exception('Need LHA information for external parameter "%s".'
                             % name)
        self.lhablock = lhablock
        self.lhacode = lhacode
 
 
all_CTparameters = []
 
 
class CTParameter(UFOBaseClass):
 
    require_args = ['name', 'nature,', 'type', 'value', 'texname']
 
    def __init__(
        self,
        name,
        type,
        value,
        texname,
        ):
 
        args = (name, 'internal', type, value, texname)
 
        UFOBaseClass.__init__(self, *args)
 
        args = (name, 'internal', type, value, texname)
 
        self.nature = 'interal'
 
        global all_CTparameters
        all_CTparameters.append(self)
 
    def finite(self):
        try:
            return self.value[0]
        except KeyError:
            return 'ZERO'
 
    def pole(self, x):
        try:
            return self.value[-x]
        except KeyError:
            return 'ZERO'
 
 
all_vertices = []
 
 
class Vertex(UFOBaseClass):
 
    require_args = ['name', 'particles', 'color', 'lorentz', 'couplings']
 
    def __init__(
        self,
        name,
        particles,
        color,
        lorentz,
        couplings,
        **opt
        ):
 
        args = (name, particles, color, lorentz, couplings)
 
        UFOBaseClass.__init__(self, *args, **opt)
 
        args = (particles, color, lorentz, couplings)
 
        global all_vertices
        all_vertices.append(self)
 
 
all_CTvertices = []
 
 
class CTVertex(UFOBaseClass):
 
    require_args = [
        'name',
        'particles',
        'color',
        'lorentz',
        'couplings',
        'type',
        'loop_particles',
        ]
 
    def __init__(
        self,
        name,
        particles,
        color,
        lorentz,
        couplings,
        type,
        loop_particles,
        **opt
        ):
 
        args = (
            name,
            particles,
            color,
            lorentz,
            couplings,
            type,
            loop_particles,
            )
 
        UFOBaseClass.__init__(self, *args, **opt)
 
        args = (
            particles,
            color,
            lorentz,
            couplings,
            type,
            loop_particles,
            )
 
        global all_CTvertices
        all_CTvertices.append(self)
 
 
all_couplings = []
 
 
class Coupling(UFOBaseClass):
 
    require_args = ['name', 'value', 'order']
 
    require_args_all = ['name', 'value', 'order', 'loop_particles',
                        'counterterm']
 
    def __init__(
        self,
        name,
        value,
        order,
        **opt
        ):
 
        args = (name, value, order)
        UFOBaseClass.__init__(self, *args, **opt)
        global all_couplings
        all_couplings.append(self)
 
    def value(self):
        return self.pole(0)
 
    def pole(self, x):
        """ the self.value attribute can be a dictionary directly specifying the Laurent serie using normal
        parameter or just a string which can possibly contain CTparameter defining the Laurent serie."""
 
        if isinstance(self.value, dict):
            if -x in self.value.keys():
                return self.value[-x]
            else:
                return 'ZERO'
 
        CTparam = None
        for param in all_CTparameters:
            pattern = re.compile(r"(?P<first>\A|\*|\+|\-|\()(?P<name>"
                                 + param.name + r")(?P<second>\Z|\*|\+|\-|\))")
            numberOfMatches = len(pattern.findall(self.value))
            if numberOfMatches == 1:
                if not CTparam:
                    CTparam = param
                else:
                    raise UFOError, \
                        'UFO does not support yet more than one occurence of CTParameters in the couplings values.'
            elif numberOfMatches > 1:
                raise UFOError, \
                    'UFO does not support yet more than one occurence of CTParameters in the couplings values.'
 
        if not CTparam:
            if x == 0:
                return self.value
            else:
                return 'ZERO'
        else:
            if CTparam.pole(x) == 'ZERO':
                return 'ZERO'
            else:
 
                def substitution(matchedObj):
                    return matchedObj.group('first') + '(' + CTparam.pole(x) \
                        + ')' + matchedObj.group('second')
 
                pattern = re.compile(r"(?P<first>\A|\*|\+|\-|\()(?P<name>"
                                     + CTparam.name
                                     + r")(?P<second>\Z|\*|\+|\-|\))")
                return pattern.sub(substitution, self.value)
 
 
all_lorentz = []
 
 
class Lorentz(UFOBaseClass):
 
    require_args = ['name', 'spins', 'structure']
 
    def __init__(
        self,
        name,
        spins,
        structure='external',
        **opt
        ):
 
        args = (name, spins, structure)
        UFOBaseClass.__init__(self, *args, **opt)
 
        global all_lorentz
        all_lorentz.append(self)
 
 
all_functions = []
 
 
class Function(object):
 
    def __init__(
        self,
        name,
        arguments,
        expression,
        ):
 
        global all_functions
        all_functions.append(self)
 
        self.name = name
        self.arguments = arguments
        self.expr = expression
 
    def __call__(self, *opt):
 
        for (i, arg) in enumerate(self.arguments):
            exec '%s = %s' % (arg, opt[i])
 
        return eval(self.expr)
 
 
all_orders = []
 
 
class CouplingOrder(object):
 
    def __init__(
        self,
        name,
        expansion_order,
        hierarchy,
        perturbative_expansion=0,
        ):
 
        global all_orders
        all_orders.append(self)
 
        self.name = name
        self.expansion_order = expansion_order
        self.hierarchy = hierarchy
        self.perturbative_expansion = perturbative_expansion
 
 
all_decays = []
 
 
class Decay(UFOBaseClass):
 
    require_args = ['particle', 'partial_widths']
 
    def __init__(
        self,
        particle,
        partial_widths,
        **opt
        ):
 
        args = (particle, partial_widths)
        UFOBaseClass.__init__(self, *args, **opt)
 
        global all_decays
        all_decays.append(self)
 
        # Add the information directly to the particle
        particle.partial_widths = partial_widths
 
 
all_form_factors = []
 
 
class FormFactor(UFOBaseClass):
 
    require_args = ['name', 'type', 'value']
 
    def __init__(
        self,
        name,
        type,
        value,
        **opt
        ):
 
        args = (name, type, value)
        UFOBaseClass.__init__(self, *args, **opt)
 
        global all_form_factors
        all_form_factors.append(self)
 
 
all_propagators = []
 
 
class Propagator(UFOBaseClass):
 
    require_args = ['name', 'numerator', 'denominator']
 
    def __init__(
        self,
        name,
        numerator,
        denominator=None,
        **opt
        ):
 
        args = (name, numerator, denominator)
        UFOBaseClass.__init__(self, *args, **opt)
 
        global all_propagators
        all_propagators.append(self)