### $${B_s^0}$$ B s 0 – $${\bar{B}}_s^0$$ B ¯ s 0 mixing within minimal flavor-violating two-Higgs-doublet models

The European Physical Journal C Springer Science and Business Media LLC 75:12 (2015) 594

#### Authors:

Qin Chang, Pei-Fu Li, Xin-Qiang Li

### Mixing and $CP$ violation in $D^0 \to K^- π^+$ decays

ArXiv 2106.02014 (2021)

#### Authors:

Tommaso Pajero, Michael Joseph Morello

#### Abstract:

The theoretical parametrisation of mixing and time-dependent $CP$ violation for $D^0$decays into two hadrons is reviewed, along with the experimental methods to measure them. While these phenomena are usually neglected for $D^0 \to K^- \pi^+$ decays, this approximation is not always justified at the current level of experimental precision. In particular, it is shown to produce a bias on the measurement of the parameter $y_{CP}$, when this is performed by relying on $D^0 \to K^- \pi^+$ decays as normalisation channel, whose size is around 40% of the precision of the current world average. The sensitivity to $CP$ violation in the mixing achievable by studying $D^0 \to K^- \pi^+$ and untagged $D \to K^- \pi^+$ decays, where $D$ stands for either of $D^0$ or $\bar{D}^0$ mesons, is also estimated.

### Search for time-dependent $CP$ violation in $D^0 \to K^+ K^-$ and $D^0 \to π^+ π^-$ decays

ArXiv 2105.09889 (2021)

#### Abstract:

A search for time-dependent violation of the charge-parity symmetry in $D^0 \to K^+ K^-$ and $D^0 \to \pi^+ \pi^-$ decays is performed at the LHCb experiment using proton-proton collision data recorded from 2015 to 2018 at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb$^{-1}$. The $D^0$ meson is required to originate from a $D^*(2010)^+ \to D^0 \pi^+$ decay, such that its flavour at production is identified by the charge of the accompanying pion. The slope of the time-dependent asymmetry of the decay rates of $D^0$ and $\bar{D}^0$ mesons into the final states under consideration is measured to be $\Delta Y_{K^+ K^-} = (-2.3 \pm 1.5 \pm 0.3) \times 10^{-4}$, $\Delta Y_{\pi^+ \pi^-} = (-4.0 \pm 2.8 \pm 0.4)\times 10^{-4}$, where the first uncertainties are statistical and the second are systematic. These results are compatible with the conservation of the charge-parity symmetry at the level of 2 standard deviations and improve the precision by nearly a factor of two.

### Measurement of the D -> K-pi(+)pi(+)pi(-) and D -> K-pi(+)pi(0) coherence factors and average strong-phase differences in quantum-correlated D(D)over-bar decays

JOURNAL OF HIGH ENERGY PHYSICS Springer Science and Business Media LLC 2021:5 (2021) ARTN 164

#### Authors:

M Ablikim, Mn Achasov, M Albrecht, Sa Cetin, Jf Chang, Wl Chang, G Chelkov, Dy Chen, G Chen, Hs Chen, Ml Chen, Sj Chen, Xr Chen, Yb Chen, Zj Chen, Ws Cheng, G Cibinetto, F Cossio, Xf Cui, Hl Dai, Xc Dai, A Dbeyssi, Re de Boer, D Dedovich, Yi Zhang

#### Abstract:

The decays D → K π π π and D → K π π are studied in a sample of quantum-correlated DD¯ pairs produced through the process e e → ψ(3770) → DD¯ , exploiting a data set collected by the BESIII experiment that corresponds to an integrated luminosity of 2.93 fb . Here D indicates a quantum superposition of a D and a D¯ meson. By reconstructing one neutral charm meson in a signal decay, and the other in the same or a different final state, observables are measured that contain information on the coherence factors and average strong-phase differences of each of the signal modes. These parameters are critical inputs in the measurement of the angle γ of the Unitarity Triangle in B → DK decays at the LHCb and Belle II experiments. The coherence factors are determined to be R = 0.52−0.10+0.12 and RKππ0 = 0.78 ± 0.04, with values for the average strong-phase differences that are δDK3π=(167−19+31)° and δDKππ0=(196−15+14)°, where the uncertainties include both statistical and systematic contributions. The analysis is re-performed in four bins of the phase-space of the D → K π π π to yield results that will allow for a more sensitive measurement of γ with this mode, to which the BESIII inputs will contribute an uncertainty of around 6°. [Figure not available: see fulltext.] − + + − − + 0 + − −1 0 − − − + + − K3π

### Time-independent measurements of the CKM angle ?

Proceedings of Science 390 (2021)

#### Abstract:

A goal of the LHCb experiment is to measure the CKM angle with a precision of 1 . At this precision it is hoped that hints or indeed an observation of physics beyond the standard model could arise. In order to reach this precision it will be necessary to target a number of decays modes. Results from two analyses are presented here which make use of the entire Run1 and Run2 dataset collected at the LHCb experiment. One of them leads to a measurement of ? = (68.7 ) , which is the most precise result from a single measurement. ? + 5 2 ? - 5 2