pyccoonfrom __future__ import division
import itertools
from common import UNITS, CONST
from particles import STATISTICS
from interactions import Interaction
from interactions.three_particle import ThreeParticleM, ThreeParticleIntegral
from interactions.four_particle import FourParticleIntegral
from library.SM import WeakM, particles as SM_particlesclass particles(object):
@staticmethod
def sterile_neutrino(mass=33.9 * UNITS.MeV):
return {
'name': 'Sterile neutrino (Majorana)',
'symbol': 'N',
'statistics': STATISTICS.FERMION,
'mass': mass,
'dof': 2,
'decoupling_temperature': 1. * UNITS.GeV,
'majorana': True
} @staticmethod
def dirac_sterile_neutrino(mass=33.9 * UNITS.MeV):
return {
'name': 'Sterile neutrino (Dirac)',
'symbol': 'N',
'statistics': STATISTICS.FERMION,
'mass': mass,
'dof': 4,
'decoupling_temperature': 1. * UNITS.GeV,
'majorana': False
}SOMETHING IS CLEARLY NOT RIGHT
K1 = 2. if active_a == active_b else 1
return Interaction(
name="Sterile-active neutrino scattering",
particles=((sterile, active_b), (active_a, active_b)),
antiparticles=((False, False), (False, False)),
Ms=(WeakM(K1=theta**2 * K1, order=(0, 1, 2, 3)), ),
integral=FourParticleIntegral
) @staticmethod
def sterile_active_to_leptons(theta=1., g_L=CONST.g_R+0.5,
sterile=None, active=None, lepton=None): return Interaction(
name="Sterile decay into neutrino and leptons pair",
particles=((sterile, active), (lepton, lepton)),
antiparticles=((False, True), (True, False)),
Ms=(
WeakM(K1=4. * g_L**2 * theta**2, order=(0, 3, 1, 2)),
WeakM(K1=4. * CONST.g_R**2 * theta**2, order=(0, 2, 1, 3)),
WeakM(K2=4. * CONST.g_R * g_L * theta**2, order=(2, 3, 0, 1))
),
integral=FourParticleIntegral
) @classmethod
def sterile_leptons_interactions(cls, thetas=None, sterile=None,
neutrinos=None, leptons=None):
g_R = CONST.g_R
inters = []Neutrinos scatterings
for neutrino_a, neutrino_b in itertools.product(neutrinos, neutrinos):
if thetas[neutrino_a.flavour]:
inters.append(cls.sterile_active_scattering(
theta=thetas[neutrino_a.flavour],
sterile=sterile,
active_a=neutrino_a,
active_b=neutrino_b
))Interactions of neutrinos and leptons
for lepton in leptons:
for neutrino in neutrinos:
if thetas[neutrino.flavour]:
g_L = g_R + 0.5 if lepton.flavour == neutrino.flavour else g_R - 0.5
inters.append(cls.sterile_active_to_leptons(
theta=thetas[neutrino.flavour],
g_L=g_L,
sterile=sterile,
active=neutrino,
lepton=lepton
))
return inters @staticmethod
def sterile_quark_interactions(thetas=None, sterile=None,
neutrinos=None, leptons=None, quarks=None):
inters = []
for quark in quarks:
for active in neutrinos:
if thetas[active.flavour]:
inters.append(interactions.sterile_quark_neutral(
theta=thetas[active.flavour], sterile=sterile,
active=active, quark=quark
))
for up, down in itertools.product([q for q in quarks if q.Q == 2./3.],
[q for q in quarks if q.Q == -1./3.]):
for lepton in leptons:
if thetas[lepton.flavour]:
inters.append(interactions.sterile_quark_charged(
theta=thetas[lepton.flavour], sterile=sterile,
lepton=lepton, up=up, down=down
))
return inters @staticmethod
def sterile_quark_neutral(theta=1., sterile=None, active=None, quark=None):
g_R = CONST.g_R
if quark.Q == 2./3.:
x = (3 - 4 * g_R)
if quark.Q == -1./3.:
x = (3 - 2 * g_R)
return Interaction(
name="Sterile-quarks neutral channel interaction",
particles=((sterile, active), (quark, quark)),
antiparticles=((False, True), (False, True)),
Ms=(
WeakM(K1=32./9. * g_R * theta**2, order=(0, 3, 1, 2)),
WeakM(K1=2./9. * x**2 * theta**2, order=(0, 2, 1, 3)),
WeakM(K2=16./9. * g_R * x * theta**2, order=(0, 1, 2, 3)),
),
integral=FourParticleIntegral
) @staticmethod
def sterile_quark_charged(theta=1., sterile=None, lepton=None, up=None, down=None):
CKM = SM_particles.quarks.CKM[(up.family, down.family)]
return Interaction(
name="Sterile-quarks charged channel interaction",
particles=((sterile, lepton), (up, down)),
antiparticles=((False, True), (False, True)),
Ms=(
WeakM(K1=.5 * CKM**2 * theta**2, order=(0, 2, 1, 3)),
WeakM(K1=.5 * CKM**2 * theta**2, order=(0, 3, 1, 2)),
),
integral=FourParticleIntegral
) @classmethod
def sterile_hadrons_interactions(cls, thetas=None, sterile=None, neutrinos=None,
leptons=None, hadrons=None):
inters = []
for neutrino in neutrinos:
if thetas[neutrino.flavour]:
for meson in hadrons:
if meson.Q == 0:
inters += cls.sterile_pion_neutral(theta=thetas[neutrino.flavour],
sterile=sterile,
active=neutrino,
pion=meson)
for lepton in leptons:
if thetas[lepton.flavour]:
for meson in hadrons:
if meson.Q == -1:
inters += cls.sterile_pion_charged(theta=thetas[lepton.flavour],
sterile=sterile,
lepton=lepton,
pion=meson)
return inters @staticmethod
def sterile_pion_neutral(theta=1., sterile=None, active=None, pion=None):
return [Interaction(
name="Sterile neutrino decay to neutral pion and neutrino",
particles=((sterile, ), (active, pion)),
antiparticles=antiparticles,
Ms=(ThreeParticleM(K=(CONST.G_F * theta * CONST.f_pi)**2
* sterile.mass**2 * (sterile.mass**2 - pion.mass**2)), ),
integral=ThreeParticleIntegral
) for antiparticles in [
((False, ), (False, False)),
((True, ), (True, False))
]] @staticmethod
def sterile_pion_charged(theta=1., sterile=None, lepton=None, pion=None):
CKM = SM_particles.quarks.CKM[(1, 1)]
return [Interaction(
name="Sterile neutrino decay to charged pion and lepton",
particles=((sterile, ), (lepton, pion)),
antiparticles=antiparticles,
Ms=(ThreeParticleM(
K=(CONST.G_F * theta * CONST.f_pi * CKM)**2
* (
(sterile.mass**2 - lepton.mass**2)**2
- pion.mass**2 * (sterile.mass**2 + lepton.mass**2)
)
),),
integral=ThreeParticleIntegral
) for antiparticles in [
((False, ), (False, True)),
((True, ), (True, False))
]]