The VCS Collaboration (VCSC) at Jefferson Lab is a scientific consortium whose mission focuses on pursuing precision measurements of the electromagnetic polarizabilities of the proton, by conducting experiments that utilize unpolarized & polarized electron (positron) beam at JLab.
Proton is the only composite building block of matter that is stable in nature. Consequently, understanding the formation of the visible matter in the universe relies on explaining the dynamics and the properties of the proton’s bound state. A fundamental property of the proton involves the response of the system to an external electromagnetic field. In order to study and to understand this response, one has to measure the proton polarizabilities, which are fundamental characteristics of any composite system, just as its mass or shape. They describe how easily the charge and magnetization distributions inside the proton are distorted by an electromagnetic field, and as such they disclose essential information about the underlying system dynamics and provide a key for decoding the proton structure in terms of the theory of the strong interaction that binds its elementary quark and gluon constituents.