Speaker
Description
The three-nucleon force (3NF) is essentially important to clarify various nuclear phenomena, such as the binding energy of light mass nuclei [1], the equation of state of nuclear matter [2] and few-nucleon scattering systems [3]. The isospin $T=3/2$ components of the 3NF also play an important role in many-nucleon systems especially for neutron-rich nuclei as well as neutron matter properties. Proton-$^3$He ($p$-$^3$He) scattering is one of the simplest prove for studying the $T=3/2$ components of the 3NF. With the aim of exploring the properties of the 3NF we are planning the measurement of $p$-$^3$He elastic scattering with the polarized $^3$He target at intermediate energies ($E/A \ge 65~{\rm MeV}$).
In the conference we present the measured spin correlation coefficient $C_{y,y}$ for $p$-$^3\rm He$ elastic scattering at 100 MeV at the angles $\theta_{\rm c.m.}=46.9^\circ$--$149.2^\circ$ in the center of mass system [4]. The experiment was performed using a 100 MeV polarized proton beam in conjunction with the polarized $^3$He target at RCNP, Osaka University in Japan. Proton beams were injected to the target, and scattered protons were detected by using $E$-$\Delta E$ detectors which consisted of plastic and NaI(Tl) scintillators. The data are compared with rigorous numerical calculations based on realistic $NN$ potentials as well as with the $\Delta$-isobar excitation. The obtained results indicate that the $C_{y,y}$ expands the knowledge of the nuclear interactions with $\Delta$-isobar or those including 3NFs that are masked in nucleon-deuteron elastic scattering.
[1] S. C. Pieper $\it et~al.$, Phys. Rev. C $\bf 64$, 014001 (2001).
[2] A. Akmal $\it et~al.$, Phys. Rev. C $\bf 58$, 1804 (1998).
[3] N. Kalantar-Nayestanaki $\it et~al.$, Rep. Prog. Phys. $\bf 75$, 016301 (2012).
[4] A.~Watanabe $\it et~al.$, Phys. Rev. C $\bf 106$, 052002 (2022).
