As well known, if the Higgs boson were not observed at LHC, the technicolor model would be the most favorable candidate responsible for the symmetry breaking. To overcome some defects in the previous model, some extende
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.
Based on a sample of 1.31 billion $J/psi$ events collected with the BESIII detector, we perform a search for the rare decay $etarightarrow 4pi^{0}$ via $J/psirightarrowgammaeta$. No significant $eta$ signal is observed in the invariant mass spectrum of 4$pi^{0}$. With a Bayesian approach, the upper limit on the branching fraction of $etarightarrow 4pi^{0}$ is determined to be $mathcal{B}(etarightarrow 4pi^{0})$ $< 4.94times10^{-5}$ at the 90% confidence level, which is a factor of six smaller than the previous experimental limit.
The reaction pp->pppi0pi0 has been investigated at a beam energy of 1.4 GeV using the WASA-at-COSY facility. The total cross section is found to be (324 +- 21_systematic +- 58_normalization) mub. In order to to study the production mechanism, differential kinematical distributions have been evaluated. The differential distributions indicate that both initial state protons are excited into intermediate Delta(1232) resonances, each decaying into a proton and a single pion, thereby producing the pion pair in the final state. No significant contribution of the Roper resonance N*(1440) via its decay into a proton and two pions is found
A partial wave analysis (PWA) of the $pi^- pi^- pi^+$ and $pi^- pi^0 pi^0$ systems produced in the reaction $pi^- p to (3pi)^-p$ at 18 GeV/$c$ was carried out using an emph{isobar} model assumption. This analysis is based on 3.0M $pi^- pi^0 pi^0$ events and 2.6M $pi^- pi^-pi^+$ events and shows production of the $a_1(1260)$, $a_2(1320)$, $pi_2(1670)$ and $a_4(2040)$ resonances. Results of detailed studies of the stability of partial wave fits are presented. An earlier analysis of 250K $pi^- pi^- pi^+$ events from the same experiment showed possible evidence for a $J^{PC}=1^{-+}$ exotic meson with a mass of $sim$1.6 GeV/$c^2$ decaying into $rho pi$. In this analysis of a higher statistics sample of the $(3pi)^-$ system in two charged modes we find no evidence of an exotic meson.
We calculate the full one-loop electroweak corrections to tri-boson production (ZZZ and WWZ) at the ILC. This is important to understand the Standard Model (SM) gauge quartic couplings which can be a window on the mechanism of spontaneous symmetry breaking. We find that even after subtracting the leading QED corrections, the electroweak corrections can still be large especially as the energy increases.
Qing-Peng Qiao
,Zuo Li
,Xue-Qian Li
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(2008)
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"The NLO corrections of $H_{TC} Pi ^0$and $Pi ^ + Pi ^ - $ pair production at the ILC in the TC2 model"
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Qing-Peng Qiao
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