How large can the SM contribution to CP violation in $D^0-{\bar{D}}^0$ mixing be?

Abstract

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.

14 pages, considerably extended version of 0904.3971 with completely new main aspect; text (except title and abstract) identical to the version accepted by JHEP

References in corpus (5)

• Averages of b-hadron and c-hadron Properties at the End of 2007
• Measurement of $\boldmath {B_s^0}$ mixing parameters from the flavor-tagged decay
• New Physics contributions to the lifetime difference in D0-anti-D0 mixing
• Mixing and lifetimes of $b$-hadrons
• New Physics from Flavour

Cited by in corpus (49)

• Implications of LHCb measurements and future prospects
• Evidence for CP violation in time-integrated D0 -> h-h+ decay rates
• Anatomy of New Physics in B-Bbar mixing
• Direct CP violation in two-body hadronic charmed meson decays
• Less space for a new family of fermions
• Measurement of $CP$ asymmetry in $D^0\to K^{-}{K}^{+}$ and $D^0\to {\pi }^{-}{\pi }^{+}$ decays
• On the ultimate precision of meson mixing observables
• Repercussions of Flavour Symmetry Breaking on CP Violation in D-Meson Decays
• Dimension-six matrix elements for meson mixing and lifetimes from sum rules
• On $D\to X_u{l}^{+}{l}^{-}$ within the Standard Model and Frameworks like the Littlest Higgs Model with T Parity
• First observation of the decay $B_{s2}^{\ast }(5840{)}^0\to B^{\ast +}{K}^{-}$ and studies of excited $B_s$ mesons
• $\Delta A_{CP}$ within the Standard Model and beyond
• Sum Rules of Charm CP Asymmetries beyond the SU(3)${}_F$ Limit
• Observation of the mass difference between neutral charm-meson eigenstates
• Conclusions from CDF Results on CP Violation in D^0 \to π^+π^-, K^+K^- and Future Tasks
• Measurement of $D^0$-$\overline{D}{}^0$ Mixing and Search for Indirect $CP$ Violation Using $D^0\to K_S^0{\pi }^{+}{\pi }^{-}$ Decays
• Measurements of indirect CP asymmetries in $D^0\to K^{-}{K}^{+}$ and $D^0\to {\pi }^{-}{\pi }^{+}$ decays
• $D^0$-${\overline{D}}^0$ mixing parameter $y$ in the factorization-assisted topological-amplitude approach
• Anatomy of ${\epsilon }^{\prime }/\epsilon$ beyond the Standard Model
• Mixing and $CP$ violation in the charm system
• On CP Asymmetries in Two-, Three- and Four-Body D Decays
• Measurement of indirect $CP$ asymmetries in $D^0\to K^{-}{K}^{+}$ and $D^0\to {\pi }^{-}{\pi }^{+}$ decays using semileptonic $B$ decays
• Theoretical update of $B$-Mixing and Lifetimes
• Dispersive and Absorptive CP Violation in $D^0-\overline{D^0}$ Mixing
• Measurement of the $CP$ violation parameter $A_{\Gamma }$ in $D^0\to K^{+}{K}^{-}$ and $D^0\to {\pi }^{+}{\pi }^{-}$ decays
• Model-independent search for CP violation in D0 to K-K+pi-pi+ and D0 to pi-pi+pi+pi- decays
• Measurement of absolute branching fraction of the inclusive decay ${\Lambda }_c^{+}\to \Lambda +X$
• Search for time-dependent $CP$ violation in $D^0\to K^{+}{K}^{-}$ and $D^0\to {\pi }^{+}{\pi }^{-}$ decays
• Manifestations of Warped Extra Dimension in Rare Charm Decays and Asymmetries
• The Impact of a 4th Generation on Mixing and CP Violation in the Charm System
• Renormalisation scale setting for D-mixing
• Brief Review of Charm Physics
• The Lepton Sector of a Fourth Generation
• Dispersive analysis of neutral meson mixing
• Measuring $CP$ violation and mixing in charm with inclusive self-conjugate multibody decay modes
• Short distance D-Dbar mixing
• Theoretical status of the CKM Matrix
• Recent advances in charm mixing and $CP$ violation at LHCb
• Quark-hadron duality for heavy meson mixings in the 't Hooft model
• Selected Topics in Heavy Flavour Physics
• Revisiting quark-hadron duality for heavy meson non-leptonic decays in two-dimensional QCD
• Experimental constraints from flavour changing processes and physics beyond the Standard Model
• Searching for New Physics by means of Relative Phases and Moduli of Decay Amplitudes
• Challenges for New Physics in the Flavour Sector
• Charm mixing in the Standard Model: the inclusive approach
• A Review of $CP$ Violation Measurements in Charm at LHCb
• CP asymmetries in $D\to P{P}^{\prime }$ decays
• CKM studies in the charm sector
• Theory overview of charm physics