Comments on ISR method in modern experiment and influence of final state radiation

We study the effect of final state radiation in the process $e^++e^- \to \bar p+ p$, in the kinematical conditions of BaBar and BESIII experiment. We show that this effect could be large, in particular in the low $x$ region ($x$ is the photon energy fraction) and should be taken into account.Comment: 8 pages, 5 figure

On the measurement of χ2(3P2)\chi_2(^3P_2) quarkonium state in the processes e++e−→pˉ+pe^++e^-\to \bar p+p and pˉ+p→e++e−\bar p+p\to e^++e^-

The intermediate quarkonium state $\chi_2(^3P_2)$ in electron-positron annihilation to proton and antiproton as well as in antiproton-proton annihilation to electron and positron can produce backward-forward asymmetry, when populated through two photon exchange. We use the dispersion relation method, which permits to express the asymmetry in terms of partial widths of quarkonium decay. The asymmetry dependence on the center of mass energy in the range near the resonance is presented. The comparison with a similar effect in these reactions with the neutral $Z$-boson in the intermediate state is given. We show that these effects are $\le 10^{-3}$. The main source of asymmetry is of pure QED origin ($\sim 10^{-2}$) which arises from the interference between initial and final state real photon emission