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The $e^+ e^-to 2(pi^+pi^-)pi^0$, 2(pi^+pi^-)eta$, $K^+ K^-pi^+pi^-pi^0$ and $K^+ K^-pi^+pi^-eta$ Cross Sections Measured with Initial-State Radiation

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 Added by Evgeni Solodov P
 Publication date 2008
  fields
and research's language is English




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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.



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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 report measurements of the observed cross sections for $e^+e^-toomega pi^+pi^-$, $omega K^+K^-$, $omega pbar p$, $K^+K^-rho^0pi^0$, $K^+K^-rho^+pi^-+c.c.$, $K^{*0}K^-pi^+pi^0+c.c.$, $K^{*+}K^-pi^+pi^-+c.c.$, $phipi^+pi^-pi^0$ and $Lambda bar Lambda pi^0$ at $sqrt s=$ 3.773 and 3.650 GeV. Upper limits (90% C.L.) are given for observed cross sections and for $psi(3770)$ decay branching fractions for production of these final states. These measurements are made by analyzing the data sets of 17.3 pb$^{-1}$ collected at $sqrt{s}=3.773$ GeV and 6.5 pb$^{-1}$ collected at $sqrt{s}=3.650$ GeV with the BES-II detector at the BEPC collider.
Using data samples collected with the BESIII detector at center-of-mass energies $sqrt{s} = 4.23, 4.26, 4.36,$ and $4.42$~rm{GeV}, we measure the branching fractions of $eta_cto K^+K^-pi^0$, $K^0_S K^{pm}pi^{mp}$, $2(pi^+pi^-pi^0)$, and $p bar{p}$, via the process $e^+e^-topi^+pi^-h_c$, $h_ctogammaeta_c$. The corresponding results are $(1.15pm0.12pm0.10)%$, $(2.60pm0.21pm0.20)%$, $(15.2pm1.8pm1.7)%$, and $(0.120pm0.026pm0.015)%$, respectively. Here the first uncertainties are statistical, and the second ones systematic. Additionally, the charged track multiplicity of $eta_c$ decays is measured for the first time.
We study the processes $e^+ e^-to K_S^0 K_L^0 gamma$, $K_S^0 K_L^0 pi^+pi^-gamma$, $K_S^0 K_S^0 pi^+pi^-gamma$, and $K_S^0 K_S^0 K^+K^-gamma$, where the photon is radiated from the initial state, providing cross section measurements for the hadronic states over a continuum of center-of-mass energies. The results are based on 469 fb$^{-1}$ of data collected with the BaBar detector at SLAC. We observe the $phi(1020)$ resonance in the $K_S^0 K_L^0$ final state and measure the product of its electronic width and branching fraction with about 3% uncertainty. We present a measurement of the $e^+ e^-to K_S^0 K_L^0 $ cross section in the energy range from 1.06 to 2.2 GeV and observe the production of a resonance at 1.67 GeV. We present the first measurements of the $e^+ e^-to K_S^0 K_L^0 pi^+pi^-$, $K_S^0 K_S^0 pi^+pi^-$, and $K_S^0 K_S^0 K^+K^-$ cross sections, and study the intermediate resonance structures. We obtain the first observations of jpsi decay to the $K_S^0 K_L^0 pi^+pi^-$, $K_S^0 K_S^0 pi^+pi^-$, and $K_S^0 K_S^0 K^+K^-$ final states.
94 - K. Arms , et al. 2003
Using a data sample corresponding to 13.7 fb^-1 collected with the CLEO II and II.V detectors, we report new branching fraction measurements for two Cabibbo-suppressed decay modes of the D^+ meson: Br(D^+ to pi^+ pi^0) = (1.3 +/- 0.2) x 10^-3 and Br(D^+ to bar{K}^0 K^+) = (5.2 +/- 0.6) x 10^-3 which are significant improvements over past measurements. The errors include statistical and systematical uncertainties as well as the uncertainty in the absolute D^+ branching fraction scale. We also set the first 90% confidence level upper limit on the branching fraction of the doubly Cabibbo-suppressed decay mode Br(D^+ to K^+ pi^0) < 4.2 x 10^-4.
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