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Register a new userMeasurement of the $e^+e^-to K^0_{scriptscriptstyle S}K^pmpi^{mp}pi^0$ and $K^0_{scriptscriptstyle S}K^pmpi^mpeta$ cross sections using initial-state radiation
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The BABAR Collaboration
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The processes $e^+e^-to K^0_{scriptscriptstyle S}K^pmpi^{mp}pi^0$ and $e^+e^-to K^0_{scriptscriptstyle S}K^pmpi^{mp}eta$ are studied over a continuum of energies from threshold to 4 GeV with the initial-state photon radiation method. Using 454 fb$^{-1}$ data collected with the BABAR detector at the SLAC PEP-II storage ring, the first measurements of the cross sections for these processes are obtained. The intermediate resonance structures from $K^{*0}(Kpi)^0$, $K^{*}(892)^pm(Kpi)^mp$ and $K^0_{scriptscriptstyle S}K^pmrho^{mp}$ are studied. The $J/psi$ is observed in all of these channels, and corresponding branching fractions are measured.
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We study the processes $e^+ e^-to K^+ K^- pi^+pi^-gamma$, $K^+K^-pi^0pi^0gamma$ and $K^+ K^- K^+ K^-gamma$, where the photon is radiated from the initial state. About 34600, 4400 and 2300 fully reconstructed events, respectively, are selected from 232 invfb of babar data. The invariant mass of the hadronic final state defines the effective epem center-of-mass energy, so that the $K^+ K^- pi^+pi^-gamma$ data can be compared with direct measurements of the $e^+ e^-to K^+K^- pipi$ reaction; no direct measurements exist for the $e^+ e^-to K^+ K^- pi^0pi^0$ or $epemto K^+ K^- K^+ K^-$ reactions. Studying the structure of these events, we find contributions from a number of intermediate states, and we extract their cross sections where possible. In particular, we isolate the contribution from $e^+ e^-tophi(1020) f_{0}(980)$ and study its structure near threshold. In the charmonium region, we observe the $J/psi$ in all three final states and several intermediate states, as well as the $psi(2S)$ in some modes, and measure the corresponding branching fractions. We see no signal for the Y(4260) and obtain an upper limit of $BR_{Y(4260)tophipi^+pi^-}cdotGamma^{Y}_{ee}<0.4 ev$ at 90% C.L.
We study the processes e+e- --> K+ K- pi+pi-gamma, K+ K- pi0pi0gamma, and K+ K- K+ K-gamma, where the photon is radiated from the initial state. About 84000, 8000, and 4200 fully reconstructed events, respectively, are selected from 454 fb-1 of BaBar data. The invariant mass of the hadronic final state defines the epem center-of-mass energy, so that the K+ K- pi+pi- data can be compared with direct measurements of the e+e- --> K+ K- pi+pi- reaction. No direct measurements exist for the e+e- --> K+ K-pi0pi0 or e+e- --> K+ K-K+ K- reactions, and we present an update of our previous result with doubled statistics. Studying the structure of these events, we find contributions from a number of intermediate states, and extract their cross sections. In particular, we perform a more detailed study of the e+e- --> phi(1020)pipigamma reaction, and confirm the presence of the Y(2175) resonance in the phi(1020) f0(980) and K+K-f0(980) modes. In the charmonium region, we observe the J/psi in all three final states and in several intermediate states, as well as the psi(2S) in some modes, and measure the corresponding product of branching fraction and electron width.
We study the processes $e^+ e^-to 2(pi^+pi^-)pi^0gamma$, $2(pi^+pi^-)etagamma$, $K^+ K^-pi^+pi^-pi^0gamma$ and $K^+ K^-pi^+pi^-etagamma$ with the hard photon radiated from the initial state. About 20000, 4300, 5500 and 375 fully reconstructed events, respectively, are selected from 232 fb$^{-1}$ of BaBar data. The invariant mass of the hadronic final state defines the effective $e^+ e^-$ center-of-mass energy, so that the obtained cross sections from the threshold to about 5 GeV can be compared with corresponding direct epem measurements, currently available only for the $etapi^+pi^-$ and $omegapi^+pi^-$ submodes of the $e^+ e^-to 2(pi^+pi^-)pi^0$ channel. Studying the structure of these events, we find contributions from a number of intermediate states, and we extract their cross sections where possible. In particular, we isolate the contribution from $e^+ e^-toomega(782)pi^+pi^-$ and study the $omega(1420)$ and $omega(1650)$ resonances. In the charmonium region, we observe the $J/psi$ in all these final states and several intermediate states, as well as the $psi(2S)$ in some modes, and we measure the corresponding branching fractions.
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.
A search for previously unobserved decays of beauty baryons to the final states $K^0_{rmscriptscriptstyle S} p pi^{-}$ and $K^0_{rmscriptscriptstyle S}p K^{-}$ is reported. The analysis is based on a data sample corresponding to an integrated luminosity of $1.0,$fb$^{-1}$ of $pp$ collisions. The $Lambda^0_{b} rightarrow overline{kern -0.2em K}^0_{rmscriptscriptstyle S}p pi^{-}$ decay is observed with a significance of $8.6,sigma$, with branching fraction begin{eqnarray*} {cal{B}}(Lambda^0_{b} rightarrow overline{kern -0.2em K}^0 p pi^{-}) & = & left(1.26 pm 0.19 pm 0.09 pm 0.34 pm 0.05 right) times 10^{-5} ,, end{eqnarray*} where the uncertainties are statistical, systematic, from the ratio of fragmentation fractions $f_{Lambda}/f_{d}$, and from the branching fraction of the $B^0 rightarrow K^0_{rmscriptscriptstyle S}pi^{+}pi^{-}$ normalisation channel, respectively. A first measurement is made of the $CP$ asymmetry, giving begin{eqnarray*} A_{C/!P} (Lambda^0_{b} rightarrow overline{kern -0.2em K}^0 p pi^{-}) & = & 0.22 pm 0.13mathrm{,(stat)} pm 0.03mathrm{,(syst)} , . end{eqnarray*} No significant signals are seen for $Lambda^0_{b} rightarrow K^0_{rmscriptscriptstyle S}p K^{-}$ decays, $Xi^{0}_{b}$ decays to both the $K^0_{rmscriptscriptstyle S}p pi^{-}$ and $K^0_{rmscriptscriptstyle S}p K^{-}$ final states, and the $Lambda^0_{b} rightarrow D^{-}_{s} (rightarrow K^0_{rmscriptscriptstyle S} K^{-}) p$ decay, and upper limits on their branching fractions are reported.
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