Test of QCD at large $Q^2$ with exclusive hadronic processes

Abstract

My report consists of two parts: (1). Using samples of 102 million $\Upsilon(1S)$ and 158 million $\Upsilon(2S)$ events at Belle, we study 17 exclusive hadronic decays of these two bottomonium resonances to some Vector-Pseudoscalar (VP), Vector-Tensor (VT) and Axial-vector-Pseudoscalar (AP) processes and their final states. Branching fractions are measured for all the processes. The ratios of the branching fractions of $\Upsilon(2S)$ and $\Upsilon(1S)$ decays into the same final state are used to test a perturbative QCD (pQCD) prediction for OZI-suppressed bottomonium decays. (2). Using data samples of 89 fb$^{-1}$, 703 fb$^{-1}$, and 121 fb$^{-1}$ collected at center-of-mass (CMS) energies 10.52, 10.58, and 10.876~GeV, respectively, we measure the cross sections of $e^+e^- \to \omega\pi^0$, $K^{\ast}(892)\bar{K}$, and $K_2^{\ast}(1430)\bar{K}$. The energy dependence of the cross sections is presented.