Using data collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider, we measure the energy dependence of the $e^+e^- \to h_b(nP)\pi^+\pi^-$ $(n=1,2)$ cross sections from thresholds up to $11.02\,$GeV. We find clear $\Upsilon(10860)$ and $\Upsilon(11020)$ peaks with little or no continuum contribution. We study the resonant substructure of the $\Upsilon(11020) \to h_b(nP)\pi^+\pi^-$ transitions and find evidence that they proceed entirely via the intermediate isovector states $Z_b(10610)$ and $Z_b(10650)$. The relative fraction of these states is loosely constrained by the current data: the hypothesis that only $Z_b(10610)$ is produced is excluded at the level of 3.3 standard deviations, while the hypothesis that only $Z_b(10650)$ is produced is not excluded at a significant level.
Center-of-mass energies, integrated luminosities and Born cross sections for all energy points. The first uncertainty in the energy is uncorrelated, the second is correlated. The three uncertainties in the cross sections are statistical, uncorrelated systematic and correlated systematic.
We report results on studies of the e+e- annihilation into three-body Y(nS)pi+pi- (n=1,2,3) final states including measurements of cross sections and the full amplitude analysis. The cross sections measured at sqrt(s)=10.865 GeV and corrected for the initial state radiation are sigma(e+e-=>Y(1S)pi+pi-)=(2.27+-0.12+-0.14) pb, sigma(e+e-=>Y(2S)pi+pi-)=(4.07+-0.16+-0.45) pb, and sigma(e+e-=>Y(3S)pi+pi-)=(1.46+-0.09+-0.16) pb. Amplitude analysis of the three-body Y(nS)pi+pi- final states strongly favors I^G(J^P)=1^+(1^+) quantum-number assignments for the two bottomonium-like Zb+- states, recently observed in the Y(nS)pi+- and hb(mP)pi+- (m=1,2) decay channels. The results are obtained with a $121.4 1/fb data sample collected with the Belle detector at the KEKB asymmetric-energy e+e- collider.
The measured cross section and visible cross section for the three-body transition E+ E- --> UPSILON(1S) PI+ PI-.
The measured cross section and visible cross section for the three-body transition E+ E- --> UPSILON(2S) PI+ PI-.
The measured cross section and visible cross section for the three-body transition E+ E- --> UPSILON(3S) PI+ PI-.
The cross sections of the processes $e^+ e^- \to K^+ K^- J/\psi$ and $K_S^0K_S^0J/\psi$ are measured via initial state radiation at center-of-mass energies between the threshold and 6.0~GeV using a data sample of 980~fb$^{-1}$ collected with the Belle detector on or near the $\Upsilon(nS)$ resonances, where $n=$1, 2, ..., 5. The cross sections for $e^+ e^- \to K^+ K^- J/\psi$ are at a few pb level and the average cross section for $e^+ e^- \to K_S^0K_S^0J/\psi$ is $1.8\pm 0.6 (\rm stat.)\pm 0.3 (\rm syst.)$~pb between 4.4 and 5.2~GeV. All of them are consistent with previously published results with improved precision. A search for resonant structures and associated intermediate states in the cross section of the process $e^+ e^- \to K^+ K^- J/\psi$ is performed.
Cross section for K+ K- J/PSI production as a function of SQRT(S). Upper limits include the systematic errors.
Cross section for K0S K0S J/PSI production as a function of SQRT(S).
Average cross section for K0S K0S J/PSI production.
We report a high-statistics measurement of the differential cross section of the process gamma gamma --> K^0_S K^0_S in the range 1.05 GeV <= W <= 4.00 GeV, where W is the center-of-mass energy of the colliding photons, using 972 fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy e^+ e^- collider operated at and near the Upsilon-resonance region. The differential cross section is fitted by parameterized S-, D_0-, D_2-, G_0- and G_2-wave amplitudes. In the D_2 wave, the f_2(1270), a_2(1320) and f_2'(1525) are dominant and a resonance, the f_2(2200), is also present. The f_0(1710) and possibly the f_0(2500) are seen in the S wave. The mass, total width and product of the two-photon partial decay width and decay branching fraction to the K bar{K} state Gamma_{gamma gamma}B(K bar{K}) are extracted for the f_2'(1525), f_0(1710), f_2(2200) and f_0(2500). The destructive interference between the f_2(1270) and a_2(1320) is confirmed by measuring their relative phase. The parameters of the charmonium states chi_{c0} and chi_{c2} are updated. Possible contributions from the chi_{c0}(2P) and chi_{c2}(2P) states are discussed. A new upper limit for the branching fraction of the P- and CP-violating decay channel eta_c --> K^0_S K^0_S is reported. The detailed behavior of the cross section is updated and compared with QCD-based calculations.
The W dependence of the cross section after integrating up to |cosTheta*|<0.8 and 0.6.
The cos(Theta*) dependence of the differential cross section for the W ranges 1.10-1.11, 1.11-1.12 and 1.12-1.13.
The cos(Theta*) dependence of the differential cross section for the W ranges 1.13-1.14, 1.14-1.15 and 1.15-1.16.
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