Nuclear density dependence of polarization transfer in quasi-elastic $A(\vec{e}, e'\vec{p})$ reactions

Kolar, Tim (author), Brecelj, Tilen (author), Mihovilovič, Miha (author), Požun, Matej (author), Širca, Simon (author), Štajner, Samo (author)

The ratio of the transverse and longitudinal components of polarization transfer to protons in the quasielastic ($\vec{e}, e'\vec{p}$) reaction, $P'_x/P'_z$, is sensitive to the proton’s electromagnetic form factor ratio, $G_E/G_M$. To explore densitydependent 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 $^{12}$C and $1d_{3/2}$,$2s_{1/2}$ in $^{40}$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 impulseapproximation (RDWIA) calculation and present the double ratios $(P'_x/P'_z)_{\mathrm{Data}}/(P'_x/P'_z)_{\mathrm{RDWIA}}$ as well as the superratios $[(P'_x/P'_z)_\mathrm{A}/(P'_x/P'_z)_\mathrm{B}]_{\mathrm{Data}}/[(P'_x/P'_z)_\mathrm{A}/(P'_x/P'_z)_\mathrm{B}]_{\mathrm{RDWIA}}$, 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 super-ratios, we observed a systematic variation between pairs of higher- and lower-density shells.

• Language: English
• Keywords: nuclear physics, nuclear reactions
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Author Accepted Manuscript
• Year: 2024
• Number of pages: Str. L061302-1-L061302-6
• Numbering: Vol. 110, iss. 6
• PID: 20.500.12556/RUL-166879
• UDC: 539.1
• ISSN on article: 2469-9985
• DOI: 10.1103/PhysRevC.110.L061302
• COBISS.SI-ID: 219253251
• Publication date in RUL: 29.01.2025

Record is a part of a journal

• Title: Physical review
• Shortened title: Phys. rev., C
• Publisher: American Physical Society
• ISSN: 2469-9985
• COBISS.SI-ID: 29756967

Secondary language

• Language: Slovenian
• Keywords: jedrska fizika, jedrske reakcije