1. Nuclear density dependence of polarization transfer in quasi-elastic ${\rm A}(\vec{e},e' \vec{p})$ reactions
- Author
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Kolar, T., Cosyn, W., Giusti, C., Achenbach, P., Ashkenazi, A., Böhm, R., Bosnar, D., Brecelj, T., Christmann, M., Cohen, E. O., Distler, M. O., Doria, L., Eckert, P., Esser, A., Gilman, R., Geimer, J., Gülker, P., Hoek, M., Izraeli, D., Kegel, S., Klag, P., Kohl, Y., Korover, I., Lichtenstadt, J., Littich, M., Manoussos, T., Mardor, I., Markus, D., Merkel, H., Mihovilovič, M., Müller, J., Müller, U., Olivenboim, M., Pätschke, J., Paul, S. J., Piasetzky, E., Plura, S., Pochodzalla, J., Požun, M., Ron, G., Schlimme, B. S., Schoth, M., Schulz, F., Sfienti, C., Stengel, S., Spreckels, R., Štajner, S., Stephan, E., Strauch, S., Szyszka, C., Širca, S., Thiel, M., Weber, A., Wilczek, A., and Yaron, I.
- Subjects
Nuclear Experiment ,Nuclear Theory - Abstract
The ratio of the transverse and longitudinal component of polarization transfer to protons in the quasi-elastic $(\vec{e}, e^{\prime} \vec{p}\,)$ reaction, $P^{\prime}_x/P^{\prime}_z$, is sensitive to the proton's electromagnetic form factor ratio, $G_E/G_M$. To explore density-dependent in-medium modifications, a comparison of polarization transfer ratios involving protons from distinct nuclear shells, each with different local nuclear densities, has been proposed. In this study, we present such comparisons between four shells, $1s_{1/2}$, $1p_{3/2}$ in $^{12}\mathrm{C}$ and $1d_{3/2}$, $2s_{1/2}$ in $^{40}\mathrm{Ca}$. In an effort to account for other many-body effects that may differ between shells, we use a state-of-the-art relativistic distorted-wave impulse-approximation (RDWIA) calculation and present the double ratios, $(P^{\prime}_x/P^{\prime}_z)_{\rm Data}/(P^{\prime}_x/P^{\prime}_z)_{\rm RDWIA}$ as well as the super ratios, $\left[(P^{\prime}_x/P^{\prime}_z)_{\rm A}/(P^{\prime}_x/P^{\prime}_z)_{\rm B}\right]_{\rm Data}/\left[(P^{\prime}_x/P^{\prime}_z)_{\rm A}/(P^{\prime}_x/P^{\prime}_z)_{\rm B}\right]_{\rm RDWIA}$, for chosen shells A and B, as a function of effective local nuclear densities. We find that double ratios for individual shells show a dependence on the probed effective nuclear densities. Studying the ratios, we observed a systematic variation between pairs of higher- and lower-density shells.
- Published
- 2023