| Autor: |
Cao, Hui-Yun, Zhou, Hai-Qing |
| Rok vydání: |
2018 |
| Předmět: |
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| Zdroj: |
Phys. Rev. D 99, 074007 (2019) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevD.99.074007 |
| Popis: |
In this work, the non-relativistic asymptotic behavior of the transition $q\overline{q}\rightarrow2g\rightarrow q\overline{q}$ in the $^1S_0$ channel is discussed. Different with the usual calculation which expands the physical amplitude around the quark anti-quark threshold, we take the quark anti-quark pairs as off shell and only expand the expression on the three-dimensional momenta of the quarks and anti-quarks. We calculate the results to order 6. The imagine part of the results after applying the on shell conditions can reproduce the non-relativistic QCD (NRQCD) results in leading order of $\alpha_s$. The real part of the results can be used to estimate the mass shift of the $^1S_0$ heavy quark anti-quark system due to the $2g$ annihilation effect. The results can also be used to estimate the energy shifts of the positronium system due to the two-photon annihilation. |
| Databáze: |
arXiv |
| Externí odkaz: |
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