ИСТИНА

Short range correlated (SRC) NN pairs play an important role in structure of atomic nuclei and are studied in many nuclear centers using electron beams [1]. A new step was done at BM@N in JINR [2] where the reaction 12C+p→10A+pp+N is studied using the 12C beam at energy of 4 GeV/nucleon at kinematics providing interaction of the hydrogen target with the SRC pair in the 12C. For theoretical analysis of the SRC effects in the reaction 12C+p→10A+pp+N it seems natural to use a properly modified approach [3] developed earlier (see Ref. [4] and references therein) to describe the quasi-elastic knock-out of fast deuterons from the light nuclei 12C and 7,6Li by protons in the reactions (p,pd) and (p,nd) [5]. An elementary sub-process in the (p,Nd) was the backward elastic scattering of the proton on the two-nucleon clusters p{pn}→pd and p{nn}→nd at the proton beam energy 670 MeV. Spectroscopic amplitudes for NN-pairs in the ground state of the 12C nucleus are calculated here within the translation-invariant shell model (TISM) with mixing configurations. The factorization of the two-nucleon momentum distribution over the internal nrel(qrel) and the c.m.s. ncm(kc.m.) momenta is assumed and at large qrel the squared deuteron (or singlet deuteron) wave function is used for nrel(qrel). Relativistic effects in the sub-process p+{NN}➛p+N+N are taken into account in the light-front dynamics [3]. We found [6] that the c.m. distribution of the deuteron clusters obtained within the TISM and used in [3], [4] to describe the (p,Nd) data [4] has to be modified considerably to describe the kc.m. distribution of the SCR NN pairs measured in the electron data [1].The ratio of the spin-singlet to spin-triplet {NN}s pairs is calculated. This work is supported in part by the RFBR grant № 18-02-40046. 1. E.O.Cohen et al., Phys. Rev. Lett. 121 (2018) 092501. 2. SRC@BMN proposal: http://bmnshift.jinr.ru/wiki/doku.php 3. Yu.N.Uzikov, Izv.RAN, Ser. Fiz. 84 (2020) 580. 4. M.A.Zhusupov, Yu.N.Uzikov, Fiz. El. Chast. At. Yadr. 18 (1987) 323. 5. J.Ero” et al., Nucl. Phys. A 372(1981) 317; D.Albrecht et al., Nucl.Phys. A 322 (1979) 512. 6. Yu.N.Uzikov, EPJ Web Conf., 222 (2019) 03027.