NLO QCD corrections to pseudoscalar quarkonium production with two heavy flavors in photon-photon collision

We calculate the next-to-leading order (NLO) QCD corrections to $\gamma +\gamma \to {\eta }_c+c+\overline{c}$, $\gamma +\gamma \to {\eta }_b+b+\overline{b,}$ and $\gamma +\gamma \to B_c+b+\overline{c}$ processes in the framework of nonrelativistic QCD factorization formalism. The cross sections at the SuperKEKB electron-positron collider, as well as the future collider like the Circular Electron Positron Collider, are evaluated. Numerical results indicate that the NLO corrections are significant, and the uncertainties in theoretical predictions with NLO corrections are reduced as expected. Due to the high luminosity of the SuperKEKB collider, the ${\eta }_c+c+\overline{c}$ production is hopefully observable in the near future.

Figure 1

Typical LO Feynman diagrams for $\gamma +\gamma \to \mathcal{Q}[Q_1\overline{Q_2}]+Q_2+\overline{Q_1}$ process.

Figure 2

Typical Feynman diagrams in virtual corrections.

Figure 3

Typical Feynman diagrams in real corrections.

Figure 4

The $p_t$ distribution for the ${\eta }_{c}c\overline{c}$ production via photon-photon fusion at (a) the SuperKEKB collider and (b) the CEPC. Here the renormalization scale $\mu =\sqrt{4m_c^2+p_t^2}$, the transverse momentum cut $0.2\le p_t\le 4\mathrm{GeV}$ and $1\le p_t\le 10\mathrm{GeV}$ is imposed on ${\eta }_c$, respectively.