In the QCD-inspired potential model where the quark-antiquark interaction consists of the usual one- gluon-exchange and the mixture of long-range scalar and vector linear confining potentials with the lowest order relativistic correction, we investigate the mass spectra and electromagnetic processes of a bottomonium system by using the Gaussian expansion method. It reveals that the vector component of the mixing confinement is anticonfining and takes around 18.51% of the confining potential. Combining the new experimental data released by Belle, BaBar and LHC, we systematically discuss the energy levels of the bottomouium states and make the predictions of the electromagnetic decays for further experiments.
We propose to measure the decay asymmetry parameters in the hadronic weak decays of singly charmed baryons, such as Λc^＋ →Λπ^＋, Σ^0π^＋, pK0, Ξ0c →Ξ-π＋and Ω^0c →Ω^-π^＋. The joint angular formulae for these processes are presented, and are used to extract the asymmetry parameters in e^＋e^-annihilation data. Base on the currentΛ＋c data set collected at BESIII, we estimate the experimental sensitivities to measure the parameters αΛπ＋forΛ＋c →Λπ＋, αΣ＋π0for Λc^＋ →Σ＋π^0 and αΣ0π＋for Λc^＋ →Σ^0π^＋.
To measure the R value in an energy scan experiment with e＋e- collisions, precise calculation of initial state radiation is required in the event generators. We present an event generator for this consideration, which incorporates initial state radiation effects up to second order accuracy. The radiative correction factor is calculated using the totally hadronic Born cross section. The measured exclusive processes are generated according to their cross sections, while the unknown processes are generated using the LUND Area Law model, and its parameters are tuned with data collected at s = 3.65 GeV. The optimized values are validated with data in the range s = 2.2324--3.671 GeV. These optimized parameters are universally valid for event generation below the DIS threshold.
