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###############################################################################
# This is VUB.DEC by Sven Menke for the X_u l nu mixture: #
# Up(4S) -> B0 B0bar +CC #
# | | #
# | -> X_u l- nu_bar (l = e or mu) #
# | #
# -> X #
# #
# #
# Up(4S) -> B+ B- +CC #
# | | #
# | -> X_u l- nu_bar (l = e or mu) #
# | #
# -> X #
# #
# it uses the model VUB which is an O(alpha_s) triple differential decay rate #
# for the B Meson to an inclusive X_u state and a lepton and neutrino. #
# The model has the following parameters: #
# 1) mb : the b-Quark mass. The authors of hep-ph/9905351 claim that #
# a range of 4.65 GeV to 4.95 GeV is reasonable. #
# 2) a : the Fermi Motion parameter. its default is 1.29 #
# smaller values give broader distributions; larger values #
# more narrow distributions for the fermi momentum. #
# 3) alpha_s : the strong coupling constant at the b-Quark Mass. This is #
# direct proportional to the amount of the built in radiative #
# QCD corrections #
# 4) N : the number of mass thresholds. This parameter should be at #
# least 1 #
# This mechanism allows to modify the Xu mass spectra in order#
# to mix this inclusive model with exclusive models. #
# For the purpose of a dedicated standalone inclusive run this#
# parameter should be 1 #
# Extra Feature: If the parameter is set to -N (minus N) #
# the internal parameter q+/10000 is stored as the ctau #
# value of the produced Xu. It can be reconstructed by #
# multiplying the difference of the vertex times of any #
# daughter of the Xu and the Xu by 10000 and reversing the #
# boost which can be done by multiplying this number by #
# m_Xu/E_Xu (the ratio of Xu mass over Xu energy in the lab). #
# This cludge allows for easy reweighting of the Fermi-motion.#
# 5) m0 : the lowest mass threshold (must be larger than 2*m_pi) #
# 6) w0 : the relative weight for the bin ]m0,m1] if N > 1 or for the #
# entire range ]m0,Infinity] if this is the last threshold #
# 7 - 2N+3) odd : next mass threshold in ascending order. #
# 8 - 2N+4) even: next relative weight #
###############################################################################
# Create our own versions of B-, B+, B0, anti-B0 which will decay to Xu l nu
# and specify that they should be treated as antiparticles
#
Alias myB- B-
Alias myB+ B+
ChargeConj myB+ myB-
#
# the same for B0, B0bar
#
Alias myB0 B0
Alias myantiB0 anti-B0
ChargeConj myB0 myantiB0
#
#
Decay Upsilon(4S)
0.25000 B+ myB- VSS;
0.25000 B- myB+ VSS;
0.21000 B0 myantiB0 VSS_MIX dm;
0.21000 myB0 anti-B0 VSS_MIX dm;
0.04000 anti-B0 myantiB0 VSS_MIX dm;
0.04000 B0 myB0 VSS_MIX dm;
Enddecay
#
# force all myB particles to always decay to Xu l nu
#
#
Decay myantiB0
# b -> u l nu
#
.5 Xu+ e- anti-nu_e PHOTOS VUB 4.80 1.29 0.22 1 0.28 1;
.5 Xu+ mu- anti-nu_mu VUB 4.80 1.29 0.22 1 0.28 1;
#
# use the following lines instead if you need access to the hidden
# parameter q+
#
# .5 Xu+ e- anti-nu_e PHOTOS VUB 4.80 1.29 0.22 -1 0.28 1;
# .5 Xu+ mu- anti-nu_mu VUB 4.80 1.29 0.22 -1 0.28 1;
Enddecay
CDecay myB0
Decay myB+
# b -> u l nu
#
.5 Xu0 e+ nu_e PHOTOS VUB 4.80 1.29 0.22 1 0.28 1;
.5 Xu0 mu+ nu_mu VUB 4.80 1.29 0.22 1 0.28 1;
#
# use the following lines instead if you need access to the hidden
# parameter q+
#
# .5 Xu0 e+ nu_e PHOTOS VUB 4.80 1.29 0.22 -1 0.28 1;
# .5 Xu0 mu+ nu_mu VUB 4.80 1.29 0.22 -1 0.28 1;
Enddecay
CDecay myB-
End

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