相关论文: Two is better than one: The U-spin-CP anomaly in c…
The recent LHCb determination of the direct CP asymmetries in the decays $D^0 \to K^+ K^-, \pi^+ \pi^-$ hints at a sizeable breaking of two approximate symmetries of the SM: CP and U-spin. We aim at explaining the data with BSM physics and…
Recent LHCb data shows that the direct CP asymmetries of the decay modes $D^0\rightarrow \pi^+\pi^-$ and $D^0\rightarrow K^+K^-$ have the same sign, violating an improved $U$-spin limit sum rule in an unexpected way at $2.1\sigma$. From the…
We analyze patterns from CP-violating new physics (NP) in hadronic and semileptonic rare charm $\vert \Delta c \vert=\vert \Delta u\vert=1$ transitions. Observation of direct CP-violation in hadronic decays, as in $\Delta A_{\text{CP}}$,…
Charge-parity (CP) asymmetries in charm decays are extremely suppressed in the Standard Model and may well be dominated by new physics contributions. The LHCb collaboration reported the results of direct CP asymmetry measurements in $D^0\to…
I discuss hadronic decays of $D$ mesons with emphasis on the recent discovery of charm CP violation in $D^0\to K^+K^-,\pi^+\pi^-$ decays. The measured difference $\Delta a_{CP} \, \equiv \; a_{CP}^{\mathrm{dir}}(D^0\rightarrow K^+K^-) -…
The LHCb and CDF Collaborations have recently reported evidence for a CP asymmetry around -0.7% in $\Delta A_{CP}$, the difference between $A_{CP}(D^0 \to K^+ K^-)$ and $A_{CP}(D^0 \to \pi^+\pi^-)$. In the Standard Model this effect may be…
CP violation is an excellent tool for probing flavor dynamics as we learnt first with $K_L \to 2 \pi$ and later also with the weak decays of beauty mesons. LHCb 2019 data have shown CP violation for the first time in $D^0\to K^-K^+$ vs.…
Recently observed increase of direct CP asymmetry in charm meson nonleptonic decays is difficult to explain within the SM. If this effect is induced by new physics, this might be investigated in other charm processes. We propose to…
The recent LHCb measurements of the $B_s \to K^-\pi^+$ and $B_s \to K^+K^-$ rates and CP asymmetries are in agreement with U-spin expectations from $B_d \to K^+\pi^-$ and $B_d \to \pi^+\pi^-$ results. We derive the complete set of isospin,…
Recent disagreement between experimental measurments of CP violating asymmetry in D -> K+ K- and D ->pi+ pi- and theoretical Standard model expectation motivated many studies within the Standard model and beyond. Rare charm decays offer new…
Recent evidence for direct CP violation in non-leptonic charm decays cannot be easily accommodated within the Standard Model (SM). On the other hand, it fits well in new physics models generating CP violating Delta C=1 chromomagnetic dipole…
Direct CP violation in the hadronic charm decays provides a good testing ground for the Kobayashi-Maskawa mechanism in the Standard Model. Any significant deviations from the expectation would be indirect evidence of physics beyond the…
A high statistics sample of photo-produced charm from the FOCUS(E831) experiment at Fermilab has been used to search for direct CP violation in the decays D+->K_S pi+ and D+ -> K_S K+. We have measured the following asymmetry parameters…
A long-standing puzzle in charm physics is the large difference between the D0 -> K+ K- and D0 -> pi+ pi- decay rates. Recently, the LHCb and CDF collaborations reported a surprisingly large difference between the direct CP asymmetries,…
Recent measurements of the CP asymmetry in the decay $D^0 \rightarrow K_S^0 K_S^0$ by the CMS collaboration, $A_{CP}(K_S^0 K_S^0) = (6.2 \pm 3.0 \pm 0.2 \pm 0.8)\%$, and by LHCb, $A_{CP}(D^0 \to K_S^0 K_S^0) = (1.86 \pm 1.04 \pm 0.41)\%$,…
We prove a general theorem about equal CP rate differences within pairs of U-spin related charmless $B$ and $B_s$ decays. Large deviations from equalities would be evidence for new physics. Six pairs of decays into two pseudoscalar mesons…
The reported CP asymmetry in D->K^+K^- / pi^+pi^- is argued to be too large to naturally fit the SM. If so, a new source of CP violation is implied in the Delta C=1 sector with a milliweak strength. CP-odd interactions in the…
The violation of the Charge-Parity (CP) symmetry is a phenomenon described by the Standard Model (SM), however, its predictions for this violation are not enough to explain the matter-antimatter asymmetry in the visible universe.…
Evidence of CP violation in the charm sector has been observed recently by the LHCb and CDF Collaborations. The issue of whether it can be accommodated within the standard model (SM) is examined in this talk. We conclude that the CP…
According to the standard model, the Cabibbo-favored (CF) decays are $CP$ conserve at tree level. Observation of any finite $CP$ asymmetry can be received as a signal of new physics. In CF charm meson decays, $ D^0 \rightarrow K^- \pi^+ $…