Speaker
Description
Short-range correlated (SRC) NN pairs play an important role in structure of atomic nuclei and are studied using mainly electron beams [1]. A new step was done at BM@N in JINR [2] where the reaction $^{12}$C+p→$^{10}$A+pp+N is studied using the $^{12}$C beam at energy of 4 GeV/nucleon in inverse kinematics providing interaction with the hydrogen target to probe the SRC pairs in the $^{12}$C. In theoretical analysis [3] of the SRC effects in this reaction is used a properly modified approach developed earlier (see Ref. [4] and references therein) to describe the quasi-elastic knock-out of fast deuterons from the light nuclei $^{12}$C and $^{7,6}$Li by protons in the reactions (p,pd) and (p,nd) [5]. Elementary sub-processes in the (p,Nd) were the backward quasi-elastic scattering of the proton on the two-nucleon clusters p{pn}→pd and p{nn}→nd at the proton beam energy 670 MeV. As in Ref. [4], the spectroscopic amplitudes for NN-pairs in the ground state of the $^{12}$C nucleus are calculated here within the translation-invariant shell model (TISM) with mixing configurations. Factorization of the two-nucleon momentum distribution over the internal n$_\text{rel}$ (q$_\text{rel}$) and the c.m.s. n$_\text{cm}$ (k$_\text{c.m.}$) momenta is assumed and for n$_\text{rel}$ (q$_\text{rel}$) the squared deuteron (or singlet deuteron) wave function the CD Bonn NN-interaction potential is used. Relativistic effects in the sub-process p+{NN}$\rightarrow$p+N+N of quasi-elastic knockout of nucleon from the SRC pair are taken into account in the light-front dynamics [6]. We found that the c.m. distribution of the deuteron clusters obtained within the TISM and used in [4], [5] to describe the (p,Nd) data [4] has to be modified considerably [6] to describe the kc.m. distribution of the SCR NN pairs measured in the electron data [7]. The ratio of the spin-singlet to spin-triplet pairs {pp}s/{pn}t is calculated and found to be in agreement with existing data. Here the initial and final state interaction effects are estimated within the eikonal approximation using the Glauber model for the N-$^{10}$A scattering. The one-loop approximation with elastic N-$^{10}$A rescatterings is applied and the effect is found to be moderate.
This work is supported in part by the RFBR grant № 18-02-40046.
References:
1. O.Hen et al., Rev. Mod. Phys. 89, 045002 (2017) .
2. M. Patsyuk et al., Nature Phys. 17, 693 (2021); arXiv:2102.02626 [nucl-ex].
3. Yu.N. Uzikov, Izv. RAN, Ser. Fiz. 84 , 580 (2020).
4. M.A. Zhusupov, Yu.N. Uzikov, Fiz. El. Chast. At. Yadr. 18, 323 (1987).
5. J. Ero et al., Nucl. Phys. A 372, 317 (1981); D. Albrecht et al., Nucl. Phys. A 322, 512(1979).
6. Yu.N. Uzikov, EPJ Web Conf. 222, 03027 (2019).
7. E.O. Cohen et al., Phys. Rev. Lett. 121, 092501 (2018).
