Leading scientists from the Laboratory of Theoretical Physics and the Laboratory of Nuclear Problems at JINR conducted research on coherent interactions of a fast proton with the short-range NN correlations in the nucleus, using data from the BM@N Experiment at the NICA Collider. An article presenting the results of the study was published in Physical Review C in June 2024. The authors are Alexey Larionov and Yuri Uzikov.

Nuclear structure at short NN distances is still poorly understood. In particular, the full quantum structure of the nucleus with a correlated NN pair is a challenge to theory. So far, model descriptions have been limited to the average mean-field picture of the remaining nuclear system after removing the NN pair.

In the recent experiment of the BM@N Collaboration at JINR, the reactions ¹²C(p, 2pn_s)¹⁰B and ¹²C(p, 2pp_s)¹⁰Be induced by the hard elastic pp scattering were studied. Here, n_s or p_s denote the undetected slow nucleon in the rest frame of ¹²C. In contrast to the previous experiments, the residual bound nucleus was also detected, which requires a new level of theoretical understanding.

Distribution of the residual nucleus ¹⁰B momentum

In the present work, the technique of fractional parentage coefficients of the translationally invariant shell model was applied to calculate the spectroscopic amplitude of the system NN-B, where B is the remaining nuclear system. The spectroscopic amplitude enters the full amplitude of a nuclear reaction.

The relative NN-B wave function is no longer a free parameter of the model but is uniquely related to the internal state of B. The interaction of the target proton with the NN pair is considered in the impulse approximation. In addition, the authors include the initial and final state interactions of absorptive type as well as the single charge exchange processes. The calculations are in a reasonable agreement with the BM@N data.