Quantum-correlated $psi(3770) to Dbar{D}$ decays collected by the CLEO-c experiment are used to perform a first measurement of $F_+^{4pi}$, the fractional $CP$-even content of the self-conjugate decay $D to pi^+pi^-pi^+pi^-$, obtaining a value of $0.
737 pm 0.028$. An important input to the measurement comes from the use of $D to K^0_{rm S}pi^+pi^-$ and $D to K^0_{rm L}pi^+pi^-$ decays to tag the signal mode. This same technique is applied to the channels $D topi^+pi^-pi^0$ and $D to K^+K^-pi^0$, yielding $F_+^{pipipi^0} = 1.014 pm 0.045 pm 0.022$ and $F_+^{KKpi^0} = 0.734 pm 0.106 pm 0.054$, where the first uncertainty is statistical and the second systematic. These measurements are consistent with those of an earlier analysis, based on $CP$-eigenstate tags, and can be combined to give values of $F_+^{pipipi^0} = 0.973 pm 0.017$ and $F_+^{KKpi^0} = 0.732 pm 0.055$. The results will enable the three modes to be included in a model-independent manner in measurements of the unitarity triangle angle $gamma$ using $B^mp to DK^mp$ decays, and in time-dependent studies of $CP$ violation and mixing in the $Dbar{D}$ system.
Time-dependent studies of inclusive charm decays to multibody self-conjugate final states can be used to determine the indirect $CP$-violating observable $A_Gamma$ and the mixing observable $y_{CP}$, provided that the fractional $CP$-even content of
the final state, $F_+$, is known. This approach can yield significantly improved sensitivity compared with the conventional method that relies on decays to $CP$ eigenstates. In particular, $D to pi^+pi^-pi^0$ appears to be an especially powerful channel, given its relatively large branching fraction and the high value of $F_+$ that has recently been measured at charm threshold.
A binned Dalitz plot analysis of $B^pm to D K^pm$ decays, with $D to K^0_{rm S} pi^+pi^-$ and $D to K^0_{rm S} K^+ K^-$, is performed to measure the CP-violating observables $x_{pm}$ and $y_{pm}$ which are sensitive to the CKM angle $gamma$. The anal
ysis exploits 1.0 $rm fb^{-1}$ of data collected by the LHCb experiment. The study makes no model-based assumption on the variation of the strong phase of the D decay amplitude over the Dalitz plot, but uses measurements of this quantity from CLEO-c as input. The values of the parameters are found to be $x_- = (0.0 pm 4.3 pm 1.5 pm 0.6) times 10^{-2}$, $y_- = (2.7 pm 5.2 pm 0.8 pm 2.3) times 10^{-2}$, $x_+ = (-10.3 pm 4.5 pm 1.8 pm 1.4)times 10^{-2}$ and $y_+ = (-0.9 pm 3.7 pm 0.8 pm 3.0)times 10^{-2}$. The first, second, and third uncertainties are the statistical, the experimental systematic, and the error associated with the precision of the strong-phase parameters measured at CLEO-c, respectively. These results correspond to $gamma = (44^{,+43}_{,-38})^circ$, with a second solution at $gamma to gamma + 180^circ$, and $r_B = 0.07 pm 0.04$, where $r_B$ is the ratio between the suppressed and favoured B decay amplitudes.
Simulation studies are performed to assess the sensitivity of a model-independent analysis of the flavour-tagged decays $D^0 to K^0_{rm S}pi^+pi^-$ and $D^0 to K^0_{rm S}K^+K^-$ to mixing and CP violation. The analysis takes as input measurements of
the $D$ decay strong-phase parameters that are accessible in quantum-correlated $D-bar{D}$ pairs produced at the $psi(3770)$ resonance. It is shown that the model-independent approach is well suited to the very large data sets expected at an upgraded LHCb experiment, or future high luminosity $e^+e^-$ facility, and that with 100M $K^0_{rm S}pi^+pi^-$ decays a statistical precision of around 0.01 and $0.7^circ$ is achievable on the CP violation parameters $r_{CP}$ and $a_{CP}$, respectively. Even with this very large sample the systematic uncertainties associated with the strong-phase parameters will not be limiting, assuming that full use is made of the available $psi(3770)$ data sets of CLEO-c and BES-III. Furthermore, it is demonstrated that large flavour-tagged samples can themselves be exploited to provide information on the strong-phase parameters, a feature that will be beneficial in the measurement of the CKM angle $gamma/phi_3$ with $B^- to DK^-$ decays.
The charged-particle production ratios $bar{p}/p$, $K^-/K^+$, $pi^-/pi^+$, $(p + bar{p})/(pi^+ + pi^-)$, $(K^+ + K^-)/(pi^+ + pi^-)$ and $(p + bar{p})/(K^+ + K^-)$ are measured with the LHCb detector using $0.3 {rm nb^{-1}}$ of $pp$ collisions delive
red by the LHC at $sqrt{s} = 0.9$ TeV and $1.8 {rm nb^{-1}}$ at $sqrt{s} = 7$ TeV. The measurements are performed as a function of transverse momentum $p_{rm T}$ and pseudorapidity $eta$. The production ratios are compared to the predictions of several Monte Carlo generator settings, none of which are able to describe adequately all observables. The ratio $bar{p}/p$ is also considered as a function of rapidity loss, $Delta y equiv y_{rm beam} - y$, and is used to constrain models of baryon transport.
