BM@N Data Analysis Aimed at Studying SRC Pairs: One-Step Single Nucleon Knockout Measurement in Inverse Kinematics Out of a 48 GeV/c$^{12}$C Nucleus
Résumé
Nucleon knockout reactions with high energy probes are widely used to reveal the inner structure of nuclei, however, they cannot be applied to study unstable nuclei. We recently demonstrated the feasibility to access single particle and short-range correlation (SRC) properties in nuclei with hadronic probes in inverse kinematics, opening the pathway for such studies in short-lived nuclei at upcoming accelerator facilities. The experiment was carried out using the BM@N setup at JINR. A $^{12}$C beam at 4 GeV/c/u impinged on a liquid hydrogen target using a kinematically complete reaction. We show that by selecting the fragment in the $^{{12}}$C($p$,$2p$)$^{{11}}$B reaction, limitations posed by final-state interactions are overcome and single nucleon properties are probed in a single-step knockout reaction. The ground-state distributions are in agreement with theoretical calculations. We probe SRCs in the same way by the break up of SRC pairs in $^{{12}}$C($p$,$2pN$)$^{{10}}$B/$^{{10}}$Be reactions. We not only identify SRCs in such kinematical conditions for the first time but also deduce factorization and other pair properties from direct measurements. The ongoing analysis continues with the study of multi-fragmentation following quasielastic and SRC pair removal, and with 4-fold coincidence events including the recoil neutron being detected. We are also conducting studies to optimize the experimental conditions for the next scheduled beam time in 2021.