Coulomb Sum Rule states that the integration of longitudinal response of a nucleus over the range of energy excitation dominated by quasi-elastic proton knock-out process should be equal to the total number of protons in the nucleus.
The test of Coulomb Sum Rule will shed light on the question of whether or not the properties of nucleon are modified in the nuclear medium.
In order to test the Coulomb Sum Rule in nuclei, a precision measurement of inclusive electron scattering cross sections in the quasi-elastic region was performed at Jefferson Lab.
Incident electrons with energies ranging from 0.4 GeV to 4 GeV scattered from 4He, 12C, 56Fe and 208Pb nuclei at 4 scattering angles(15,60,90,120 degree) and momentum transfer ranging from 0.55 GeV/c to 1 GeV/c.
After complete all the data analysis, we expect to confirm/refute the presently controversial issue of the quenching of the longitudinal response function in medium weight nuclei and as importantly investigate the |q| evolution of the Coulomb Sum Rule as we probe significantly shorter distances.