T. Shibata, Y. Ohira, K. Kohri, R. Yamazaki
We show that the production cross-sections of $\gamma$ and e$^\pm$ in p-p collision, $\sigma_{pp\rightarrow \gamma}$ and $\sigma_{pp\rightarrow {\rm e}^\pm}$ respectively, may be kinematically equivalent without back to that of the parent pion $\sigma_{pp\rightarrow \pi}$. So we can obtain straightforwardly $\sigma_{pp\rightarrow {\rm e}^\pm}$ once we have $\sigma_{pp\rightarrow \gamma}$ with help of the machine data. We discuss in detail the relation between them, and present how reliable for $\sigma_{pp\rightarrow {\rm e}^\pm}$ even in the TeV region. Based on these studies, we give also the emissivities of $\gamma$ and e$^\pm$ in the Galaxy, and present the positron fraction observed at the solar system, the ratio of e$^+$ to [e$^+$ + e$^-$]. It is now in a vital open question that it appears to rise as the energy gets higher, $\gtrsim$\,10\,GeV, far beyond the expectation with the standard model today. The aim of the present paper is to give the production cross-section of e$^\pm$ firmly even in the TeV region, in order to see quantitatively how much deviated from the standard model in the yield of e$^\pm$ and its propagation to the Earth.
View original:
http://arxiv.org/abs/1304.0879
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