[bvll] Added direct CP asymmetry in B->Vll

flav-io · Sep 22, 2016 · 93461ca · 93461ca
1 parent 0963925
commit 93461ca
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diff --git a/flavio/physics/bdecays/bvll/observables.py b/flavio/physics/bdecays/bvll/observables.py
@@ -19,6 +19,9 @@ def dGdq2(J):
 def dGdq2_ave(J, J_bar):
     return ( dGdq2(J) + dGdq2(J_bar) )/2.
 
+def dGdq2_diff(J, J_bar):
+    return ( dGdq2(J) - dGdq2(J_bar) )/2.
+
 # denominator of S_i and A_i observables
 def SA_den(J, J_bar):
     return 2*dGdq2_ave(J, J_bar)
@@ -203,6 +206,7 @@ def fct(wc_obj, par, q2min, q2max):
 
 _tex = {'e': 'e', 'mu': '\mu', 'tau': r'\tau'}
 _observables = {
+'ACP': {'func_num': dGdq2_diff, 'tex': r'A_\text{CP}', 'desc': 'Direct CP asymmetry'},
 'AFB': {'func_num': AFB_experiment_num, 'tex': r'A_\text{FB}', 'desc': 'forward-backward asymmetry'},
 'FL': {'func_num': FL_num, 'tex': r'F_L', 'desc': 'longitudinal polarization fraction'},
 'S3': {'func_num': lambda J, J_bar: S_experiment_num(J, J_bar, 3), 'tex': r'S_3', 'desc': 'CP-averaged angular observable'},

diff --git a/flavio/physics/bdecays/bvll/test_bvll.py b/flavio/physics/bdecays/bvll/test_bvll.py
@@ -31,6 +31,13 @@ def test_compare_to_Davids_old_code(self):
         self.assertAlmostEqual(flavio.sm_prediction("dBR/dq2(B0->K*mumu)", q2=1)/5.7131974656129313e-8, 1, delta=delta)
         self.assertAlmostEqual(flavio.sm_prediction("dBR/dq2(B0->K*mumu)", q2=6)/5.524478678779278e-8, 1, delta=delta)
         self.assertAlmostEqual(flavio.sm_prediction("dBR/dq2(B0->K*mumu)", q2=15)/7.412258847550239e-8, 1, delta=delta)
+        # direct CP asymmetry should be close to 0
+        self.assertAlmostEqual(flavio.sm_prediction("ACP(B0->K*mumu)", q2=1), 0, delta=0.01)
+        self.assertAlmostEqual(flavio.sm_prediction("ACP(B0->K*mumu)", q2=6), 0, delta=0.01)
+        self.assertAlmostEqual(flavio.sm_prediction("ACP(B0->K*mumu)", q2=17), 0, delta=0.01)
+        self.assertAlmostEqual(flavio.sm_prediction("ACP(B+->K*mumu)", q2=1), 0, delta=0.01)
+        self.assertAlmostEqual(flavio.sm_prediction("ACP(B+->K*mumu)", q2=6), 0, delta=0.01)
+        self.assertAlmostEqual(flavio.sm_prediction("ACP(B+->K*mumu)", q2=17), 0, delta=0.01)
         # this is just a very rough comparison to the literature
         delta = 0.2
         self.assertAlmostEqual(flavio.sm_prediction("P1(B0->K*mumu)", q2=3), 0, delta=delta)