Speaker
Description
Recently the BM@N Collaboration [1] measured the missing momentum and residual nucleus momentum distributions in proton knock-out reactions $^{12}\mbox{C}(p,2pn_s)^{10}\mbox{B}$ and $^{12}\mbox{C}(p,2pp_s)^{10}\mbox{Be}$ in the inverse kinematics with incident $^{12}\mbox{C}$ beam at 48 GeV/c on proton target. Here, "s" stands for an unobserved spectator (or recoil) nucleon. The missing momentum is defined as the momentum of a struck proton in the $^{12}\mbox{C}$ rest frame before knock-out. The observed back-to-back correlation of the missing momentum and the spectator neutron momentum for $p_{\rm miss} \geq 350$ MeV/c indicates that the proton interacted with a short-range $pn$-correlation. We perform the theoretical analysis of this experiment by applying the approach based on the translationally-invariant shell model (TISM) [2] which allows to calculate the spectroscopic amplitude of the state of "$NN$-pair + residual nucleus" in the wave function of the initial nucleus. Our calculations include absorptive initial- and final state interactions and charge exchange processes. In contrast to other approaches, we do not use a phenomenological c.m. momentum distribution of the $NN$-correlation, but calculate it from the TISM. A good overall agreement with the BM@N data is reached.
[1] M. Patsyuk et al., Nature Phys. {\bf 17}, 693 (2021).
[2] Yu. Uzikov and A. Uvarov, Phys. Part. Nucl. {\bf 53}, 426 (2022).
