EvtGen and CP-physics
Here are some of the CP related distributions that I have generated
with EvtGen.
First I have looked at B->pipi. Here the "only"
interesting
distribution is the difference in time
(in the Upsilon restframe) between the decays of the
two B's. (time is expressed as c*t and is given in mm.)
The other decay that I have looked at is B->J/PSI K*
with J/PSI->e+e- and K*->K pi. Here there are many more
interesting
distribution
since the decay distributions are
time dependent. In the figure the decay angle of the
K* is shown for (tcp-ttag) greater than 0 and less than 0.
And the tistributions are clearly different.
The generation of these events were done with the following
decay file (the parameters for the decay B->J/PSI KS given
after the decay model "SVV_CP" are a bit arbitrary, the two
first are the mass difference and beta.):
Decay UPS4
1.000 2 B0 B0B VSS
Enddecay
Decay B0
1.000 2 PSI K*0 SVV_CP 0.51e12 0.4 1.0 1.0 0.0 1.0 0.0 1.0 0.0
Enddecay
Decay PSI
1.000 2 E+ E- VLL
Enddecay
Decay K*0
1.000 2 K0 pi0 VSS
Enddecay
Decay B0B
1.000 3 D+ e- nueb ISGW2
Enddecay
End