def three_particle_free_non_equilibrium_test(params):
eps = 1e-14
photon = Particle(**SMP.photon)
neutrino_e = Particle(**SMP.leptons.neutrino_e)
neutrino_mu = Particle(**SMP.leptons.neutrino_mu)
sterile = Particle(**NuP.dirac_sterile_neutrino(mass=140 * UNITS.MeV))
neutral_pion = Particle(**SMP.hadrons.neutral_pion)
theta = 1e-3
thetas = defaultdict(float, {
'electron': theta,
})
interaction = NuI.sterile_hadrons_interactions(
thetas = thetas, sterile=sterile,
neutrinos = [neutrino_e],
leptons = [],
mesons = [neutral_pion]
)
universe = Universe(params=params)
universe.add_particles([photon, neutrino_e, neutrino_mu, sterile, neutral_pion])
universe.interactions += interaction
params.update(universe.total_energy_density(), universe.total_entropy())
universe.update_particles()
universe.init_interactions()
photon_distribution = photon._distribution
neutrino_e_distribution = neutrino_e._distribution
neutrino_mu_distribution = neutrino_mu._distribution
sterile_distribution = sterile._distribution
neutral_pion_distribution = neutral_pion._distribution
universe.calculate_collisions()
assert all(photon.collision_integral == 0), "Equilibrium particle integral is non-zero"
assert all(numpy.abs(neutrino_e.collision_integral * params.h) < eps), "Integrals do not cancel"
assert all(numpy.abs(sterile.collision_integral * params.h) < eps), "Integrals do not cancel"
assert all(numpy.abs(neutral_pion.collision_integral * params.h) < eps), "Integrals do not cancel"
assert all(neutrino_mu.collision_integral == 0), "Free particle integral is non-zero"
universe.update_distributions()
assert all(photon._distribution == photon_distribution),\
"Equilibrium particle distribution changed"
assert all(neutrino_e._distribution - neutrino_e_distribution < eps),\
"Interacting particle distribution changed"
assert all(sterile._distribution - sterile_distribution < eps),\
"Interacting particle distribution changed"
assert all(neutral_pion._distribution - neutral_pion_distribution < eps),\
"Interacting particle distribution changed"
assert all(neutrino_mu._distribution == neutrino_mu_distribution),\
"Free particle distribution changed"
def four_particle_decay_test(params):
os.environ['SPLIT_COLLISION_INTEGRAL'] = ''
photon = Particle(**SMP.photon)
neutrino_e = Particle(**SMP.leptons.neutrino_e)
sterile = Particle(**NuP.dirac_sterile_neutrino(mass=200 * UNITS.MeV))
theta = 1e-4
thetas = defaultdict(float, {
'electron': theta,
})
interaction = NuI.sterile_leptons_interactions(
thetas=thetas, sterile=sterile,
neutrinos=[neutrino_e],
leptons=[],
kind = CollisionIntegralKind.F_f_vacuum_decay
)
for inter in interaction:
inter.integrals = [integral for integral in inter.integrals
if sum(reactant.side for reactant in integral.reaction) in [2]]
universe = Universe(params=params)
universe.add_particles([photon, neutrino_e, sterile])
universe.interactions += interaction
params.update(universe.total_energy_density(), universe.total_entropy())
universe.update_particles()
universe.init_interactions()
collision_integral = sterile.collision_integrals[0].integrate(sterile.grid.TEMPLATE)
theo_value = (CONST.G_F * theta)**2 * sterile.mass**5 / (192 * numpy.pi**3) / UNITS.MeV
decay_rate = -(collision_integral * sterile.params.H \
* sterile.conformal_energy(sterile.grid.TEMPLATE) / sterile.conformal_mass \
/ sterile._distribution) / UNITS.MeV
ratio = decay_rate / theo_value
assert any(numpy.abs(val) - 1 < 1e-2 for val in ratio), "Four-particle decay test failed"
def three_particle_decay_test(params):
os.environ['SPLIT_COLLISION_INTEGRAL'] = ''
photon = Particle(**SMP.photon)
neutrino_e = Particle(**SMP.leptons.neutrino_e)
sterile = Particle(**NuP.dirac_sterile_neutrino(mass=200 * UNITS.MeV))
neutral_pion = Particle(**SMP.hadrons.neutral_pion)
theta = 1e-2
thetas = defaultdict(float, {
'electron': theta,
})
interaction = NuI.sterile_hadrons_interactions(
thetas = thetas, sterile=sterile,
neutrinos = [neutrino_e],
leptons = [],
mesons = [neutral_pion],
kind = CollisionIntegralKind.F_f_vacuum_decay
)
universe = Universe(params=params)
universe.add_particles([photon, neutrino_e, sterile, neutral_pion])
universe.interactions += interaction
params.update(universe.total_energy_density(), universe.total_entropy())
universe.update_particles()
universe.init_interactions()
collision_integral = sterile.collision_integrals[0].integrate(sterile.grid.TEMPLATE)
theo_value = (CONST.G_F * theta * neutral_pion.decay_constant)**2 \
* sterile.mass**3 * (1 - (neutral_pion.mass / sterile.mass)**2)**2 \
/ (16 * numpy.pi) / UNITS.MeV
decay_rate = -(collision_integral * sterile.params.H \
* sterile.conformal_energy(sterile.grid.TEMPLATE) / sterile.conformal_mass \
/ sterile._distribution) / UNITS.MeV
ratio = decay_rate / theo_value
assert any(numpy.abs(val) - 1 < 1e-2 for val in ratio), "Three-particle decay test failed"