A Mathematica based Version of the CKMfitter Package

58 Chapter 7. Conclusions and Perspectives
Since all the present data from experiments in quark-flavor physics is well described
by the Standard Model, the space for New Physics contributions is significantly constrained.
Nevertheless, there is still enough space for possible New Physics effects,
which have been quantified in this thesis in two different extensions of the Standard
Model.
Possible New Physics contributions to neutral meson oscillations have been implemented
model-independently to the B-meson systems as well as to the Kaon system.
The allowed ranges for the NP parameters (r 2 d ,2ϑd) in the Bd system have been found
to:
r 2 d
= 1.02 +0.50
−0.42 and 2ϑd = −0.094 +0.049
−0.123 (at 68 % CL), (7.3)
which is in good agreement with the Standard Model. The small bias in 2ϑd results
from the slight disagreement of the measurements of |Vub|incl and sin 2β. Since a
significant constraint on possible New Physics in B 0 - ¯ B 0 mixing is obtained from the
observable ASL, its theoretical prediction has been implemented including LO QCD
corrections as well as NLO QCD corrections. A preliminary comparison of their SM
predictions is given in this thesis.
Contributions of charged Higgs bosons to the branching fraction of leptonic B-meson
decays have been implemented in the framework of Two-Higgs-Doublet Models. Since
only the decay B + → τ + ντ is currently experimentally accessible, the constraint
on (tan β,m H +) is still loose. An additional fit input from B → Xsγ transitions
would provide an additional constraint, but has not been implemented yet.
To guarantee the stability of the fit results by using the Mathematica based CKMfitter
package, several comparison tests with the original package have been performed.
As a benefit to the CKMfitter group, a user guide has been written during this thesis
as well as a tutorial on the coding of theory packages.
After more than one year of development, the Mathematica based version of the
CKMfitter package has been used for the first time to produce the fit results for
a large conference (ICHEP 2006). Nevertheless, a lot of features available in the
original CKMfitter package are still missing. A Wolfenstein parameter independent
prediction of B(B + → l + νl) as well as the theory of rare Kaon decays need to be
implemented.
Due to its modular structure, the new Mathematica based version of the CKMfitter
package is not only restricted to the CKM matrix analysis. Further applications,
e. g. a leptonic mixing matrix analysis could be easily added.