Measurement of polarization-transfer to bound protons in carbon and its virtuality dependence

Abstract

We measured the ratio $P_x/P_z$ of the transverse to longitudinal components of polarization transferred from electrons to bound protons in ${}^{12}\mathrm{C}$ by the ${}^{12}\mathrm{C}(\vec{e},e^{\prime }\vec{p})$ process at the Mainz Microtron (MAMI). We observed consistent deviations from unity of this ratio normalized to the free-proton ratio, $(P_x/P_z{)}_{{}^{12}\mathrm{C}}/(P_x/P_z{)}_{{}^1\mathrm{H}}$, for both $s$- and $p$-shell knocked out protons, even though they are embedded in averaged local densities that differ by about a factor of two. The dependence of the double ratio on proton virtuality is similar to the one for knocked out protons from ${}^2\mathrm{H}$ and ${}^4\mathrm{He}$, suggesting a universal behavior. It further implies no dependence on average local nuclear density.

References in corpus (3)

• Components of polarization-transfer to a bound proton in a deuteron measured by quasi-elastic electron scattering
• Nuclear Density Dependence of In-Medium Polarization
• Polar polarization: a new method for polarimetry analysis

Cited by in corpus (12)

• Components of polarization-transfer to a bound proton in a deuteron measured by quasi-elastic electron scattering
• Polarization transfer to bound protons measured by quasi-elastic electron scattering on ${}^{12}$C
• Quasi-elastic polarization-transfer measurements on the deuteron in anti-parallel kinematics
• Comparison of recoil polarization in the ${}^{12}\mathrm{C}(\vec{e},e^{\prime }\vec{p})$ process for protons extracted from $s$ and $p$ shell
• The influence of Fermi motion on the comparison of the polarization transfer to a proton in elastic $\vec{e}p$ and quasi-elastic $\vec{e}A$ scattering
• Measurement of polarization transfer in the quasi-elastic ${}^{40}\mathrm{Ca}(\vec{e},e^{\prime }\vec{p})$ process
• Measurements of the induced polarization in the quasi-elastic $A(e,e^{\prime }\vec{p})$ process in non-coplanar kinematics
• Electroweak form factors of baryons in dense nuclear matter
• Measurements of the electron-helicity asymmetry in the quasi-elastic $\mathrm{A}(\vec{e},e^{\prime }p)$ process
• Polar polarization: a new method for polarimetry analysis
• Neutron form factor measurements at MAMI
• Octet baryon electroweak form factors in dense nuclear matter