Microscopic approach to NA and AA scattering in the framework of Chiral EFT and BHF theory

Transcription

1 Microscopic approach to NA and AA scattering in the framework of Chiral EFT and BHF theory Masakazu TOYOKAWA ( 豊川将一 ) Kyushu University, Japan Kyushu Univ. Collaborators M. Yahiro, T. Matsumoto, K. Minomo, K. Ogata, and M. Kohno

2 16th June, 2015, Varenna 14th 1/13 1. Introduction Microscopic understanding of nuclear reaction is quite important in nuclear physics many-body Schrödinger Eq. with realistic NN interaction ladder diagram of NN collision

3 16th June, 2015, Varenna 14th 2/13 many-body Schrödinger Eq. with effective NN interaction Usually τ ij is replaced by g-matrix interaction (effective interaction in nuclear matter)

4 16th June, 2015, Varenna 14th 3/13 2. Aims I have two aims in the present talk. 1. I test the validity of present microscopic framework by comparing the theoretical results with the experimental data. 2. I clarify chiral-3nf effects on nucleon-nucleus and nucleus-nucleus scattering by using the microscopic framework.

5 16th June, 2015, Varenna 14th 4/13 3. Microscopic framework Chiral-2NF+3NF as a realistic NN interaction BHF theory Chiral g-matrix interaction P and T densities folding model Microscopic optical potential observables (dσ/dω, A y, σ R,,,)

6 16th June, 2015, Varenna 14th 5/13 Ch-EFT for nuclear forces Ch-EFT is the theory for determining 2NF, 3NF, and many-nucleon forces systematically. This theory was already applied for light nuclei. binding energies of Oxygen isotopes shell model calculation significant 3NF effects

7 16th June, 2015, Varenna 14th 6/13 BHF calculation for nuclear matter no free parameter reliability of BHF theory saturation point We will calculate the g matrix for positive energy in order to apply the g matrix for NA and AA scattering.

8 16th June, 2015, Varenna 14th 7/13 Folding model Chiral g matrix is folded with P and T densities in order to get the potential between P and T. Nuclear densities for light nuclei (A 40) : from electron scattering for heavy nuclei (A>40) : from Hartree-Fock with Gogny-D1S Theoretical framework without any free parameters!

9 16th June, 2015, Varenna 14th 8/13 4. Results

10 16th June, 2015, Varenna 14th 9/13 Nucleon-nucleus scattering p+ 40 Ca, 58 Ni, 208 Pb scattering at E in =65MeV

11 16th June, 2015, Varenna 14th 10/13 Nucleus-nucleus scattering 4 He+ 58 Ni, 208 Pb scattering at E in /A P =72MeV

12 16th June, 2015, Varenna 14th 11/13 Nucleus-nucleus scattering 16 O+ 16 O scattering at E in /A P =70MeV Ch-3NF effects inelastic channels?

13 16th June, 2015, Varenna 14th 12/13 Results : Optical potentials Ch-3NF effects on optical potentials p+ 208 Pb scattering at E in =65MeV N 2 LO 3NFs repulsive absorptive dominant! 4 He+ 208 Pb scattering at E in /A P =72MeV repulsive absorptive

14 16th June, 2015, Varenna 14th 13/13 Summary We constructed a new microscopic framework based on Ch-EFT, BHF theory and the g-matrix folding model. This framework well reproduces the experimental data for proton and 4 He scattering with no free parameter. This means present framework is reliable. We estimated Ch-3NF effects on NA and AA scattering. Ch-3NF effects become more important for heavier projectile. The effects make the potentials less attractive and more absorptive. The effects are mainly originated in the 2-π exchange diagram.

15 16th June, 2015, Varenna 14th 0/0 御静聴有難う御座いました

16 16th June, 2015, Varenna 14th back up Back up

17 16th June, 2015, Varenna 14th back up Near-far decomposition Scattering amplitude can be decomposed in At the backward angles p scattering strong interference 4 He scattering far side dominant Near side Far side Ch-3NF effect for the real part is seen in 4 He scattering

18 16th June, 2015, Varenna 14th back up BHF calculation Brückner-Bethe-Goldstone equation in-medium two-nucleon scattering in the nuclear matter gives the g-matrix interaction (in-medium effective interaction) g matrix includes multiple-scattering effect and medium effect g matrix depends on density (ρ) and energy (E) lowest-order Brückner theory calculation nuclear excitation effects are partly included.

19 16th June, 2015, Varenna 14th back up BHF calculation 3NFs in BHF calculation treat 3NFs as effective 2NFs with the mean-field approximation standard manner for treatment of 3NFs in nuclear matter 3NFs effects become more important as the density increases Input nuclear forces N 3 LO 2NFs and N 2 LO 3NFs parameters are determined from 2N and 3N systems cut off Λ=550MeV

20 16th June, 2015, Varenna 14th back up Localization of g matrix g-matrix interaction based on Ch-2NFs+3NFs obtained (original) g matrix is non-local localize for applicability apply the localized g matrix (chiral-g matrix) to folding model Accuracy of localization (n+p scattering at E in =65MeV case) chiral-g matrix result reproduce well original g matrix for finite ρ, the accuracy is kept to the same degree

21 16th June, 2015, Varenna 14th back up Ch-3NF effects in nuclear matter Single-particle potential in symmetric nuclear matter corresponding to the optical potential for finite nuclei decomposed in each spin (S=0,1) and isospin (T=0,1) repulsive ( 1 E) saturation property reaction attractive ( 3 E) binding energy (light nuclei) absorptive ( 3 E, 3 O) reaction

22 16th June, 2015, Varenna 14th back up Folding model Microscopic optical potentials folding g matrix with the target (and projectile) density NA scattering AA scattering same procedure for spin-orbit potential (with some approximations) knock-on exchange (a part of antisymmetrization) is included. non-locality from knock-on exchange is localized by Brieva-Rook method. local-density approximation, standard manner for treatment of g- matrix in the folding model