Physics – High Energy Physics – High Energy Physics - Phenomenology
Scientific paper
2010-02-25
JHEP 03(2010)009
Physics
High Energy Physics
High Energy Physics - Phenomenology
14 pages, considerably extended version of 0904.3971 with completely new main aspect; text (except title and abstract) identic
Scientific paper
We investigate the maximum size of CP violating effects in $D$-mixing within the Standard Model (SM), using Heavy Quark Expansion (HQE) as theoretical working tool. For this purpose we determine the leading HQE contributions and also $\alpha_s$ corrections as well as subleading $1/m_c$ corrections to the absorptive part of the mixing amplitude of neutral $D$ mesons. It turns out that these contributions to $\Gamma_{12}$ do not vanish in the exact SU$(3)_\mathrm{F}$ limit. Moreover, while the leading HQE terms give a result for $\Gamma_{12}$ orders of magnitude lower than the current experimental value, we do find a sizeable phase. In the literature it was suggested that higher order terms in the HQE might be much less affected by the severe GIM cancellations of the leading terms; it is even not excluded that these higher order terms can reproduce the experimental value of $y$. If such an enhancement is realized in nature, the phase discovered in the leading HQE terms can have a sizeable effect. Therefore, we think that statements like: {\it "CP violating effects in $D$-mixing of the order of $10^{-3}$ to $10^{-2}$ are an unambigous sign of new physics"}--given our limited knowlegde of the SM prediction--are premature. Finally, we give an example of a new physics model that can enhance the leading HQE terms to $\Gamma_{12}$ by one to two orders of magnitude.
Bobrowski Maciej
Lenz Alexander
Riedl Johann
Rohrwild Jürgen
No associations
LandOfFree
How large can the SM contribution to CP violation in $D^0-\bar D^0$ mixing be? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with How large can the SM contribution to CP violation in $D^0-\bar D^0$ mixing be?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and How large can the SM contribution to CP violation in $D^0-\bar D^0$ mixing be? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-380085