A model-independent search for direct CP violation in the Cabibbo suppressed decay \(D^+ \to K^- K^+\pi^+\) in a sample of approximately 370,000 decays is carried out. The data were collected by the ...LHCb experiment in 2010 and correspond to an integrated luminosity of 35 pb\(^{-1}\). The normalized Dalitz plot distributions for \(D^+\) and \(D^-\) are compared using four different binning schemes that are sensitive to different manifestations of CP violation. No evidence for CP asymmetry is found.
Branching fractions of the decays \(H_b\to H_c\pi^-\pi^+\pi^-\) relative to \(H_b\to H_c\pi^-\) are presented, where \(H_b\) (\(H_c\)) represents B^0-bar(\(D^+\)), \(B^-\) (\(D^0\)), B_s^0-bar ...(\(D_s^+\)) and \(\Lambda_b^0\) (\(\Lambda_c^+\)). The measurements are performed with the LHCb detector using 35\({\rm pb^{-1}}\) of data collected at \(\sqrt{s}=7\) TeV. The ratios of branching fractions are measured to be B(B^0-bar -> D^+\pi^-\pi^+\pi^-)/ B(B^0-bar -> D^+\pi^-) = 2.38\pm0.11\pm0.21 B(B^- -> D^0\pi^-\pi^+\pi^-) / B(B^- -> D^0\pi^-) = 1.27\pm0.06\pm0.11 B(B_s^0-bar -> D_s^+\pi^-\pi^+\pi^-) / B(B_s^0-bar -> D_s^+\pi^-) = 2.01\pm0.37\pm0.20 B(\Lambda_b^0->\Lambda_c^+\pi^-\pi^+\pi^-) / B(\Lambda_b^0 -> \Lambda_c^+\pi^-) = 1.43\pm0.16\pm0.13. We also report measurements of partial decay rates of these decays to excited charm hadrons. These results are of comparable or higher precision than existing measurements.
The \(\bar{\Lambda} / \Lambda\) and \(\bar{\Lambda} / K^0_\mathrm{S}\) production ratios are measured by the LHCb detector from \(0.3\,\mathrm{nb}^{-1}\) of \(pp\) collisions delivered by the LHC at ...\(\sqrt{s} = 0.9\)\,TeV and \(1.8\,\mathrm{nb}^{-1}\) at \(\sqrt{s} = 7\)\,TeV. Both ratios are presented as a function of transverse momentum, \(p_\mathrm{T}\), and rapidity, \(y\), in the ranges {\(0.15 < p_\mathrm{T} < 2.50\,\mathrm{GeV}/c\)} and {\(2.0<y<4.5\)}. Results at the two energies are in good agreement as a function of rapidity loss, \(\Delta y = y_\mathrm{beam} - y\), and are consistent with previous measurements. The ratio \(\bar{\Lambda} / \Lambda\), measuring the transport of baryon number from the collision into the detector, is smaller in data than predicted in simulation, particularly at high rapidity. The ratio \(\bar{\Lambda} / K^0_\mathrm{S}\), measuring the baryon-to-meson suppression in strange quark hadronisation, is significantly larger than expected.
