NSMAT2016 Proton elastic scattering and nucleon density - PowerPoint PPT Presentation

NSMAT2016 Proton elastic scattering and nucleon density distributions -Recent status of the ESPRI project- B01 group Juzo Zenihiro, RIKEN Nishina Center

Neu eutron ski skin an and EOS Finite nucleus Nuclear matter EOS Drawn by Density Neutron: r n (r) T. Isobe Proton Neutron Skin : r p (r) Radius 0 Density: r E r d  E r  S r d  d 2 4 ( , ) ( , 0 ) ( ) O ( ) Neutron K balance S r  S r       sym 2 3 Skin ( ) ( ) L O ( ) sat 2 Asymmetry: d thickness Symmetry energy 2016/11/22 2

Neutron skin as a probe of S( r ) E r d  E r  S r d  d 2 4 ( , ) ( , 0 ) ( ) O ( ) S ( r ) : the slope L Energy (MeV) K S r  S r       sym 2 3 NM : d = 1 ( ) ( ) L O ( ) sat 2  ρ ρ  ε sat SM : d = 0 Strong correlation! ρ 3 sat Variou Skyrme interactions Baryon density (fm -3 ) N-skin (fm) Determine the slope coefficient L of S( r )  neutron matter EOS Impact on neutron star structure • Taken from L.-W. Chen et al., PRC72, 064309. Radius, cooling system, etc. 2016/11/22 3

How to determine r p (r) & r n (r) & D r np 2     A d d ; Nuclear charge F ( q ) Electron scattering  d ch d Mott e - e -  r A A F ( q ) ( r ) : well established ch ch g   r in 1980s p F ( q ) F ( q ) ( r ) ch p p +Ze D   r r r r r ( r ), ( r ) np n p p n Proton scattering ; Nuclear matter @ 300 MeV p p  r  r meson : our work F ( q ) ( r ) ( r )  p n p n N+Z RIA + an effective NN interaction at around 300 MeV 2016/11/22 4

Precise extraction of r n (r (r) ) from proton elastic scattering at 300 300 MeV Established for stable nuclei  experiments at RCNP Pb case r n (r) : model independent SOG d  /d , Ay @ 300 MeV RIA + Medium Effect J.Zenihiro et al., Phys. Rev. C 82, 044611 2016/11/22 5

New method to extract r p (r) (r) & r n (r) (r)  Mainly for unstable nuclei Proton scattering @ 200 MeV p p   r  r 200 200 t F ( q ) t F ( q ) ( r ) ( r ) meson pp p pn n p n + Coulomb ( r ch ) N+Z r r D   ( r ), ( r ) r r r p n np n p Proton scattering @ 300 MeV p p meson   r  r 300 300 t F ( q ) t F ( q ) ( r ) ( r ) pp p pn n p n N+Z + Coulomb ( r ch ) 2016/11/22 6

Why two energies? 200 200 & 300 300 MeV/u p -A @300  ESPRI  r n (r) + r p (r) p -A @300  ESPRI  a r n (r) + b r p (r)  r n (r), r p (r) e -A  SCRIT  r ch (r) p -A @200  ESPRI  c r n (r) + d r p (r) Idea: energy dependences of pp & pn interaction 10 3 Cross section [mb] pp pn np 200 300 400 10 2 10 1 10 100 1000 E lab. [MeV]  Demonstration of the new method with Zr data 2016/11/22 7

Simultaneous extraction from two- energy p-elastic data of 90,92,94 Zr Fitting results of 90 Zr @ 200 & 300 MeV Extracted densities of 90 Zr Simultaneous search of Neutron & Proton From 300 & 200 MeV data 2016/11/22 8

Unstable nuclei -ESPRI project- E lastic S cattering of P rotons from RI beams Application to nuclei with large isospin asymmetry

ESPRI project Elastic Scattering of Protons from RI beams Extension of proton elastic scattering method to unstable nuclei 【 nuclear chart 】 208 Pb @RCNP 66,70 Ni @GSI 132 Sn@RIBF: This Spring 9,10,11,16 C @HIMAC, RIBF : doubly magic nuclei 48 Ca @RCNP process from 208 Pb 2016/11/22 10

ESPRI devices Recoil Proton Spectrometer (RPS) Solid hydrogen target Drift Chamber 1 mm t φ 30 mm Plastic scintillator 2016/11/22 11

ESPRI devices Recoil Proton Spectrometer (RPS) θ lab = 66 ° - 80 ° , Ep =20-120 MeV, ΔΩ 〜 10 msr/deg. q =1-2.2 fm -1 , ΔEx = 400-500 keV 436x436 mm 2 (x-y- x’ - y’ - x’ -y) Recoil drift chamber 440x440 mm 2 x 2 mm t Plastic scintillator 431.8x45.72 mm 2 x 50.8 mm t NaI(Tl) calorimeter 2016/11/22 12

Light unstable nuclei : 9,10,11,12,16 C Kinematical correlation : T p vs q p 9 C 10 C 11 C w/ Z=6 gated Recoil proton energy (MeV) Preliminary Preliminary 12 C 16 C w/ Z=6 gated # of analyzed beams 9 C 0.5x10 9 Preliminary Preliminary (T. Baba) 10 C 3x10 9 11 C 5x10 9 12 C 6x10 9 16 C 7x10 9 2016/11/22 13

ESPRI experiment of 132 132 Sn Sn @ RIBF Accelerators 238 U@345 Experimental RI beam production MeV/u ~20pnA CAT April – May 2016: ESPRI RIBF113(CAT)@F8 & RIBF79(ESPRI)@F12 was performed in a parasitic way. 2016/11/22 14

RIBF79R1 (ESPRI) / RIBF113 (CAT) Experiment in the parasitic mode CAT (ISGMR) 100 MeV/u 132 Sn (d,d ’) ESPRI (Skin thickness) 200 MeV/u 132 Sn (p,p) F7 F8 F12 EXP (Beam time) CAT setup @F8 ESPRI setup @F12 RIBF113 (CAT) in April (d, d’) GMR (d, d) elastic 132 Sn @ 100 MeV/u RIBF79R1 (ESPRI) in May (p, p’) GMR (p, p) elastic 132 Sn @ 200 MeV/u 2016/11/22 15

Proton elastic scattering of 132 Sn successfully measured at RIBF 132 Sn (p, p) at 200 MeV/u was measured in May 2016 : NP1512-RIBF79R1 Online plot Proton energy by NaI ESPRI detector setup 1mmt solid [ch] hydrogen target Clear Proton tof [ch] elastic event 65 70 75 [deg] 80 85 90 2016/11/22 Recoil proton angle 16

Elastic Scattering of Protons with RI beams (ESPRI) project Collaborators J. Zenihiro (RIKEN) S.Terashima (Beihang Univ.) Y.Matsuda (Tohoku Univ. CYRIC) H.Otsu (RIKEN) H.Sakaguchi (RCNP) Kyoto Univ. RCNP RIKEN T.Kawabata I.Tanihata T. Uesaka T.Murakami H.Jin Ong H.Takeda M.Tsumura J. Tanaka K.Ozeki T.Furuno K.Yoneda GSI Miyazaki Univ. S272 collaborators Tohoku Univ. Y.Maeda T.Kobayashi NIRS-HIMAC E.Takada CNS, Univ. of Tokyo S. Ota M.Kanazawa 2016/11/22 17

Summary • Constraints on the symmetry energy parameters by neutron skin thicknesses • Proton elastic scattering method : r n (r) • 204,206, 208 Pb • Recent progress • Stable nuclei • double magic nuclei : 40,42,44, 48 Ca • Simultaneous extraction of r p (r) & r n (r) from 200 & 300 MeV data : 90,92,94 Zr • Unstable nuclei • ESPRI project : 9,10,11,16 C, 20 O, 66,70 Ni • Double magic nucleus : 132 Sn  RIBF79R1 132 Sn(p,p) @ 200MeV/u • Future : • ESPRI experiment of 132 Sn @ 300 MeV/u • Next target of ESPRI : 50,52 Ca (magic ?) 2016/11/22 18