def test_uu_to_six_g(self):
"""Test the process u u > six g against literature expression"""
myleglist = base_objects.LegList()
myleglist.append(base_objects.Leg({'id':2,
'state':False,
'number': 1}))
myleglist.append(base_objects.Leg({'id':2,
'state':False,
'number': 2}))
myleglist.append(base_objects.Leg({'id':9000006,
'state':True,
'number': 3}))
myleglist.append(base_objects.Leg({'id':21,
'state':True,
'number': 4}))
myproc = base_objects.Process({'legs':myleglist,
'model':self.base_model})
evaluator = process_checks.MatrixElementEvaluator(self.base_model,
reuse = False)
p, w_rambo = evaluator.get_momenta(myproc)
amplitude = diagram_generation.Amplitude(myproc)
matrix_element = helas_objects.HelasMatrixElement(amplitude)
mg5_me_value, amp2 = evaluator.evaluate_matrix_element(matrix_element,
p)
comparison_value = uu_Dg(p, 6, evaluator.full_model)
self.assertAlmostEqual(mg5_me_value, comparison_value, 12)
def test_find_symmetry_qq_qqg_with_subprocess_group(self):
"""Test the find_symmetry function for subprocess groups"""
procs = [[2,-2,2,-2,21], [2,2,2,2,21]]
amplitudes = diagram_generation.AmplitudeList()
for proc in procs:
# Define the multiprocess
my_leglist = base_objects.LegList([\
base_objects.Leg({'id': id, 'state': True}) for id in proc])
my_leglist[0].set('state', False)
my_leglist[1].set('state', False)
my_process = base_objects.Process({'legs':my_leglist,
'model':self.base_model})
my_amplitude = diagram_generation.Amplitude(my_process)
amplitudes.append(my_amplitude)
subproc_group = \
group_subprocs.SubProcessGroup.group_amplitudes(amplitudes,"madevent")[0]
symmetry, perms, ident_perms = diagram_symmetry.find_symmetry(\
subproc_group)
self.assertEqual(len([s for s in symmetry if s > 0]), 19)
self.assertEqual(symmetry,[1, 1, 1, 1, -2, -3, -4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, -8, -9, -10, -11, -12, -13, -14, -18, -19])
return
# The test below doesn't apply with the new way of determining
# config symmetry for subprocess groups, since we don't demand
# that symmetric diagrams have identical particles.
# Check that the momentum assignments work
matrix_element = \
subproc_group.get('matrix_elements')[1]
process = matrix_element.get('processes')[0]
evaluator = process_checks.MatrixElementEvaluator(self.base_model,
auth_skipping = True,
reuse = True)
p, w_rambo = evaluator.get_momenta(process)
me_value, amp2_org = evaluator.evaluate_matrix_element(\
matrix_element, p)
for isym, (sym, perm) in enumerate(zip(symmetry, perms)):
new_p = [p[i] for i in perm]
if sym >= 0:
continue
iamp = subproc_group.get('diagram_maps')[1].index(isym+1)
isymamp = subproc_group.get('diagram_maps')[1].index(-sym)
me_value, amp2 = evaluator.evaluate_matrix_element(\
matrix_element, new_p)
self.assertAlmostEqual(amp2[iamp], amp2_org[isymamp])
def test_get_momenta(self):
"""Test the get_momenta function"""
myleglist = base_objects.LegList()
myleglist.append(base_objects.Leg({'id':-11,
'state':False,
'number': 1}))
myleglist.append(base_objects.Leg({'id':11,
'state':False,
'number': 2}))
myleglist.append(base_objects.Leg({'id':22,
'state':True,
'number': 3}))
myleglist.append(base_objects.Leg({'id':22,
'state':True,
'number': 4}))
myleglist.append(base_objects.Leg({'id':23,
'state':True,
'number': 5}))
myproc = base_objects.Process({'legs':myleglist,
'model':self.base_model})
evaluator = process_checks.MatrixElementEvaluator(self.base_model)
full_model = evaluator.full_model
p, w_rambo = evaluator.get_momenta(myproc)
# Check massless external momenta
for mom in p[:-1]:
mass = mom[0]**2-(mom[1]**2+mom[2]**2+mom[3]**2)
self.assertAlmostEqual(mass, 0., 8)
mom = p[-1]
mass = math.sqrt(mom[0]**2-(mom[1]**2+mom[2]**2+mom[3]**2))
self.assertAlmostEqual(mass,
full_model.get('parameter_dict')['mdl_MZ'],
8)
# Check momentum balance
outgoing = [0]*4
incoming = [0]*4
for i in range(4):
incoming[i] = sum([mom[i] for mom in p[:2]])
outgoing[i] = sum([mom[i] for mom in p[2:]])
self.assertAlmostEqual(incoming[i], outgoing[i], 8)
# Check non-zero final state momenta
for mom in p[2:]:
for i in range(4):
self.assertTrue(abs(mom[i]) > 0.)
def test_find_symmetry_epem_aaa(self):
"""Test the find_symmetry function"""
myleglist = base_objects.LegList()
myleglist.append(base_objects.Leg({'id':-11,
'state':False}))
myleglist.append(base_objects.Leg({'id':11,
'state':False}))
myleglist.append(base_objects.Leg({'id':22,
'state':True}))
myleglist.append(base_objects.Leg({'id':22,
'state':True}))
myleglist.append(base_objects.Leg({'id':22,
'state':True}))
myproc = base_objects.Process({'legs':myleglist,
'model':self.base_model})
myamplitude = diagram_generation.Amplitude(myproc)
matrix_element = helas_objects.HelasMatrixElement(myamplitude)
symmetry, perms, ident_perms = diagram_symmetry.find_symmetry(matrix_element)
self.assertEqual(symmetry, [6,-1,-1,-1,-1,-1])
# Check that the momentum assignments work
process = matrix_element.get('processes')[0]
evaluator = process_checks.MatrixElementEvaluator(self.base_model,
auth_skipping = True,
reuse = True)
p, w_rambo = evaluator.get_momenta(process)
me_value, amp2_org = evaluator.evaluate_matrix_element(\
matrix_element, p)
for isym, (sym, perm) in enumerate(zip(symmetry, perms)):
new_p = [p[i] for i in perm]
if sym >= 0:
continue
me_value, amp2 = evaluator.evaluate_matrix_element(matrix_element,
new_p)
self.assertAlmostEqual(amp2[isym], amp2_org[-sym-1])
def test_rotate_momenta(self):
"""Test that matrix element and amp2 identical for rotated momenta"""
myleglist = base_objects.LegList()
myleglist.append(base_objects.Leg({'id':2,
'state':False}))
myleglist.append(base_objects.Leg({'id':-2,
'state':False}))
myleglist.append(base_objects.Leg({'id':2,
'state':True}))
myleglist.append(base_objects.Leg({'id':-2,
'state':True}))
myleglist.append(base_objects.Leg({'id':21,
'state':True}))
myproc = base_objects.Process({'legs':myleglist,
'model':self.base_model})
myamp = diagram_generation.Amplitude(myproc)
matrix_element = helas_objects.HelasMatrixElement(myamp)
evaluator = process_checks.MatrixElementEvaluator(self.base_model,
auth_skipping = True,
reuse = True)
p, w_rambo = evaluator.get_momenta(myproc)
me_val, amp2 = evaluator.evaluate_matrix_element(\
matrix_element,p)
# Rotate momenta around x axis
for mom in p:
mom[2] = -mom[2]
mom[3] = -mom[3]
new_me_val, new_amp2 = evaluator.evaluate_matrix_element(\
matrix_element, p)
self.assertAlmostEqual(me_val, new_me_val, 10)
for amp, new_amp in zip(amp2, new_amp2):
self.assertAlmostEqual(amp, new_amp, 10)
def uu_to_ttng_test(self, nglue = 0):
"""Test the process u u > t t g for 4fermion models"""
myleglist = base_objects.LegList()
myleglist.append(base_objects.Leg({'id':2,
'state':False}))
myleglist.append(base_objects.Leg({'id':2,
'state':False}))
myleglist.append(base_objects.Leg({'id':6}))
myleglist.append(base_objects.Leg({'id':6}))
myleglist.extend([base_objects.Leg({'id':21}) for i in range(nglue)])
values = {}
p = None
for model in 'scalar', '4ferm':
base_model = eval('self.base_model_%s' % model)
full_model = eval('self.full_model_%s' % model)
myproc = base_objects.Process({'legs':myleglist,
'model':base_model})
evaluator = process_checks.MatrixElementEvaluator(base_model,
reuse = False)
evaluator.full_model = full_model
if not p:
p, w_rambo = evaluator.get_momenta(myproc)
amplitude = diagram_generation.Amplitude(myproc)
matrix_element = helas_objects.HelasMatrixElement(amplitude)
stored_quantities = {}
values[model] = evaluator.evaluate_matrix_element(matrix_element,
p)[0]
self.assertAlmostEqual(values['scalar'], values['4ferm'], 3)
def test_boost_momenta_gluino(self):
"""check if the momenta are boosted correctly by checking invariant mass
in the case of massive final state
"""
myleglist = base_objects.LegList()
myleglist.append(base_objects.Leg({'id':21,
'state':False,
'number': 1}))
myleglist.append(base_objects.Leg({'id':21,
'state':False,
'number': 2}))
myleglist.append(base_objects.Leg({'id':1000021,
'state':True,
'number': 3}))
myleglist.append(base_objects.Leg({'id':1000021,
'state':True,
'number': 4}))
myproc = base_objects.Process({'legs':myleglist,
'model':self.base_model})
evaluator = process_checks.MatrixElementEvaluator(self.base_model)
p, w_rambo = evaluator.get_momenta(myproc)
def invariant_mass(p1, p2):
#helping function to compute invariant mass
return p1[0] * p2[0] - p1[1] * p2[1] - p1[2] * p2[2] -p1[3] * p2[3]
# Compute invariant mass on the initial set of impulsion
invariant_mass_result = []
for p1 in p:
for p2 in p:
m12 = invariant_mass(p1, p2)
if abs(m12) < 1e-8:
m12=0
invariant_mass_result.append(m12)
self.assertTrue(m12 >= 0)
# Compute invariant mass on a x direction boost
invariant_mass_boost=[]
p_boost = process_checks.boost_momenta(p)
for p1 in p_boost:
for p2 in p_boost:
m12 = invariant_mass(p1, p2)
invariant_mass_boost.append(m12)
for i in range(len(invariant_mass_boost)):
self.assertAlmostEqual(invariant_mass_boost[i],
invariant_mass_result[i])
# Compute invariant mass on a y direction boost
invariant_mass_boost=[]
p_boost = process_checks.boost_momenta(p, boost_direction=2)
for p1 in p_boost:
for p2 in p_boost:
m12 = invariant_mass(p1, p2)
invariant_mass_boost.append(m12)
for i in range(len(invariant_mass_boost)):
self.assertAlmostEqual(invariant_mass_boost[i],
invariant_mass_result[i])
# Compute invariant mass on a z direction boost
invariant_mass_boost=[]
p_boost = process_checks.boost_momenta(p, boost_direction=3, beta=0.8)
for p1 in p_boost:
for p2 in p_boost:
m12 = invariant_mass(p1, p2)
invariant_mass_boost.append(m12)
for i in range(len(invariant_mass_boost)):
self.assertAlmostEqual(invariant_mass_boost[i],
invariant_mass_result[i])
