$\varphi$ meson transparency in nuclei from $\varphi N$ resonant interactions

We investigate the $\varphi$ meson nuclear transparency using some recent theoretical developments on the $\varphi$ in medium self-energy. The inclusion of direct resonant $\varphi N$ scattering and the kaon decay mechanisms leads to a $\varphi$ width much larger than in most previous theoretical approaches. The model has been confronted with photoproduction data from CLAS and LEPS and the recent proton induced $\varphi$ production from COSY finding an overall good agreement. The results support the need of a quite large direct $\varphi N$-scattering contribution to the self-energy.

Figure 1

Transparencies for the nucleus ${}^{20}\mathrm{Ne}$ as a function of the $\varphi$ momentum with kaon cloud self-energy only or adding the $\varphi$ self-energies from the HLS [25, 26] or the SU(6) model [28].

Figure 2

Transparencies as a function of $\varphi$ momentum for photoproduction processes, with (${\theta }_{\varphi }=0$ degrees) and without Pauli blocking for ${}^{64}\mathrm{Cu}$.

Figure 3

Ratio of $\varphi$ photoproduction transparencies as a function of the atomic number compared with data from LEPS [5].

Figure 4

Transparency ratios for $\varphi$ photoproduction as a function of the atomic number compared with data from CLAS [7]. Curves to guide the eye.

Figure 5

Nuclear transparency ratios for the $pA\to \varphi X$ reaction compared to data from Ref. [22].