New Results of SRC electron scattering measurement


  Igor Korover  
Physics department, NRCN

Short Range Correlated (SRC) pairs are two strongly interacting nucleons in temporal close proximity. SRC pairing shifts nucleons from the low-momentum nuclear shell states to high-momentum states with momenta greater than the nuclear Fermi momentum k_F.
One can study SRC contributions by measuring inclusive or exclusive electron scattering. In the later case both nucleons from the pair emerge from the nucleus and are detected. These measurements are performed in kinematic regions with large Q^2 and x_B > x_{thr}. For these kinematics the electrons scatter predominantly off nucleons with momentum above k_F, and Final State Interaction (FSI), Meson Exchange Current (MEC) effects, and inelastic contributions are largely suppressed.
Inclusive measurements require a large x_{B} threshold and do not give us the composition of the 2N-SRC pairs. On the other hand, exclusive measurements allows a lowering of the x_B threshold x_{thr}\approx 1.1 and a detailed study of the 2N-SRC pairs. However, the low statistics of the exclusive measurements limit our ability to study the dynamics of the 2N-SRC.\\
In this talk I will present new results from the exclusive measurements and compare them to theoretical calculations using the Generalized Contact Formalism with both chiral and phenomenological local nucleon-nucleon (NN) interactions. This study allows to map the transition from isospin-dependent tensor NN interaction to an isospin-independent scalar interaction at high momentum.\\
In addition to the exclusive measurements new results from a novel, semi-exclusive study will be presented. We measured the fraction of SRC pairs component in the nuclear ground state below the threshold that is needed to observe the SRC contribution in the inclusive measurements. \\

The analysis reported here was performed as a part of Data-Mining project of the CLAS detector at Jeffereson Laboratory, Hall-B. The measurements were performed with 5 GeV electron beam, on multiple solid targets (C, Al, Fe, and Pb) and on liquid Deuterium.\\