[ddecays] Added branching ratios of D(s)->lnu decays

flavio/data/config.yml

@@ -31,6 +31,9 @@ renormalization scale:
     # K decays
     kdecays: 2.  # K->pinunu
 
+    #  D decays
+    dll: 2.      # D->l nu
+
     # meson mixing
     Bs mixing: 4.2  # Bs-Bsbar mixing
     B0 mixing: 4.2  # B0-B0bar mixing

flavio/physics/bdecays/blnu.py

@@ -3,7 +3,7 @@
 import flavio
 from math import pi
 
-def br_plnu_general(wc, par, Vij, P, lep, delta=0):
+def br_plnu_general(wc, par, Vij, P, qiqj, lep, delta=0):
     r"""Branching ratio of general $P^+\to\ell^+\nu_\ell$ decay.
 
     `Vij` is the appropriate CKM matrix element.
@@ -16,7 +16,7 @@ def br_plnu_general(wc, par, Vij, P, lep, delta=0):
     tau = par['tau_'+P]
     f = par['f_'+P]
     # Wilson coefficient dependence
-    qqlnu = flavio.physics.bdecays.common.meson_quark[P] + lep + 'nu'
+    qqlnu = qiqj + lep + 'nu'
     rWC = (wc['CV_'+qqlnu] - wc['CVp_'+qqlnu]) + mP**2/ml * (wc['CS_'+qqlnu] - wc['CSp_'+qqlnu])
     N = tau * GF**2 * f**2 / (8*pi) * mP * ml**2  * (1 - ml**2/mP**2)**2
     return N * abs(Vij)**2 * abs(rWC)**2 * (1 + delta)
@@ -31,7 +31,7 @@ def br_blnu(wc_obj, par, lep):
     wc = wc_obj.get_wc('bu' + lep + 'nu', scale, par)
     # add SM contribution to Wilson coefficient
     wc['CV_bu'+lep+'nu'] += flavio.physics.bdecays.wilsoncoefficients.get_CVSM(par, scale, nf=5)
-    return br_plnu_general(wc, par, Vub, 'B+', lep, delta=0)
+    return br_plnu_general(wc, par, Vub, 'B+', 'bu', lep, delta=0)
 
 # function returning function needed for prediction instance
 def br_blnu_fct(lep):

flavio/physics/ddecays/__init__.py

@@ -0,0 +1,3 @@
+r"""Observables in $D$ meson decays."""
+
+from . import dlnu

flavio/physics/ddecays/dlnu.py

@@ -0,0 +1,40 @@
+r"""Functions for $D\to\ell\nu$."""
+
+import flavio
+from flavio.physics.bdecays.blnu import br_plnu_general
+from math import pi, log
+
+def br_Dlnu(wc_obj, par, P, lep):
+    r"""Branching ratio of $D^+\to\ell^+\nu_\ell$."""
+    # CKM element
+    if P=='D+':
+        Vij = flavio.physics.ckm.get_ckm(par)[1,0].conj() # Vcd*
+        qiqj = 'dc'
+    elif P=='Ds':
+        Vij = flavio.physics.ckm.get_ckm(par)[1,1].conj() # Vcs*
+        qiqj = 'sc'
+    scale = flavio.config['renormalization scale']['dll']
+    # Wilson coefficients
+    wc = wc_obj.get_wc(qiqj + lep + 'nu', scale, par, nf_out=4)
+    # add SM contribution to Wilson coefficient
+    wc['CV_'+qiqj+lep+'nu'] += flavio.physics.bdecays.wilsoncoefficients.get_CVSM(par, scale, nf=4)
+    return br_plnu_general(wc, par, Vij, P, qiqj, lep, delta=0)
+
+# function returning function needed for prediction instance
+def br_Dlnu_fct(P, lep):
+    def f(wc_obj, par):
+        return br_Dlnu(wc_obj, par, P, lep)
+    return f
+
+# Observable and Prediction instances
+
+_lep = {'e': 'e', 'mu': r'\mu', 'tau': r'\tau'}
+_had = {'D+': r'D^+', 'Ds': r'D_s',}
+
+for D in _had:
+  for l in _lep:
+    _obs_name = "BR("+D+"->"+l+"nu)"
+    _obs = flavio.classes.Observable(_obs_name)
+    _obs.set_description(r"Branching ratio of $"+_had[D]+r"\to "+_lep[l]+r"^+\nu_"+_lep[l]+r"$")
+    _obs.tex = r"$\text{BR}("+_had[D]+r"\to "+_lep[l]+r"^+\nu_"+_lep[l]+r")$"
+    flavio.classes.Prediction(_obs_name, br_Dlnu_fct(D, l))

flavio/physics/ddecays/test_dlnu.py

@@ -0,0 +1,20 @@
+import unittest
+import numpy as np
+import flavio
+
+constraints = flavio.default_parameters
+wc_obj = flavio.WilsonCoefficients()
+par = constraints.get_central_all()
+
+class TestDlnu(unittest.TestCase):
+    def test_dlnu(self):
+        # compare to the experimental values
+        self.assertAlmostEqual(
+            flavio.Observable.get_instance("BR(Ds->munu)").prediction_central(constraints, wc_obj),
+            5.56e-3, delta=3*0.25e-3)
+        self.assertAlmostEqual(
+            flavio.Observable.get_instance("BR(Ds->taunu)").prediction_central(constraints, wc_obj),
+            5.55e-2, delta=3*0.24e-2)
+        self.assertAlmostEqual(
+            flavio.Observable.get_instance("BR(D+->munu)").prediction_central(constraints, wc_obj),
+            3.74e-4, delta=3*0.17e-4)

flavio/physics/eft.py

@@ -41,7 +41,7 @@ def adm_ddlnu(nf, alpha_s, alpha_e):
 _ll = ['ee', 'mumu', 'tautau']
 _lilj = ['emu', 'mue', 'etau', 'taue', 'mutau', 'taumu']
 _lnu = ['enu', 'munu', 'taunu']
-_fccc = ['bc', 'bu', 'su', 'du']
+_fccc = ['bc', 'bu', 'su', 'du', 'dc', 'sc', ]
 _nunu = ['nuenue', 'numunumu', 'nutaunutau']
 _nuinuj = ['nuenumu', 'numunue', 'nuenutau', 'nutaunue', 'numunutau', 'nutaunumu']
 

flavio/physics/kdecays/klnu.py

@@ -20,7 +20,7 @@ def br_plnu(wc_obj, par, P, lep):
     wc = wc_obj.get_wc(qiqj + lep + 'nu', scale, par)
     # add SM contribution to Wilson coefficient
     wc['CV_'+qiqj+lep+'nu'] += flavio.physics.bdecays.wilsoncoefficients.get_CVSM(par, scale, nf=3)
-    return br_plnu_general(wc, par, Vij, P, lep, delta=delta_Plnu(par, P, lep))
+    return br_plnu_general(wc, par, Vij, P, qiqj, lep, delta=delta_Plnu(par, P, lep))
 
 def r_plnu(wc_obj, par, P):
     # resumming logs according to (111) of 0707.4464