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

Radius Density Proton : rp(r) Neutron: rn(r)

Neutron Skin Finite nucleus Density: r Asymmetry: d

balance

Nuclear matter EOS

) ( ) ( ) , ( ) , (

4 2

d d r r d r O    S E E

Symmetry energy

Drawn by

• T. Isobe

) ( 2 ) ( ) (

3 2 sym sat

   r r O K L     S S

Neutron Skin thickness

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N-skin (fm)

Neutron skin as a probe of S(r)

Determine the slope coefficient L

• f S(r)  neutron matter EOS

Taken from L.-W. Chen et al., PRC72, 064309.

sat sat

3 ρ ρ ρ ε  

) ( 2 ) ( ) (

3 2 sym sat

   r r O K L     S S

Baryon density (fm-3) Energy (MeV) NM : d = 1 SM : d = 0 S(r) : the slope L

) ( ) ( ) , ( ) , (

4 2

d d r r d r O    S E E

Impact on neutron star structure

• Radius, cooling system, etc.

Strong correlation!

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Variou Skyrme interactions

How to determine rp(r) & rn(r) & Drnp

+Ze N+Z e- e- p p

Electron scattering Proton scattering @ 300 MeV

g meson

) ( ) ( ) ( ) ( ) ( r q F q F r q F

p p p ch A ch A ch

r r    ) ( ) ( ) ( r r q F

n p n p

r r  



) ( ), ( r r

n p

r r

; Nuclear charge ; Nuclear matter

Mott d d A ch d d

q F

     2

) (

4 2016/11/22

RIA + an effective NN interaction at around 300 MeV

p n np

r r r   D

: well established in 1980s : our work

2016/11/22

Precise extraction of rn(r (r) ) from proton elastic scattering at 300 300 MeV

Established for stable nuclei  experiments at RCNP Pb case

d/d, Ay @ 300MeV

rn(r) : model independent SOG

RIA + Medium Effect

5

J.Zenihiro et al., Phys. Rev. C 82, 044611

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N+Z p p

Proton scattering @ 200 MeV Proton scattering @ 300 MeV

meson

) ( ), ( r r

n p

r r

p n np

r r r   D

 Mainly for unstable nuclei

N+Z p p meson

) ( ) ( ) ( ) (

200 200

r r q F t q F t

n p n pn p pp

r r    ) ( ) ( ) ( ) (

300 300

r r q F t q F t

n p n pn p pp

r r   

New method to extract rp(r) (r) & rn(r) (r)

+ Coulomb (rch) + Coulomb (rch)

Why two energies? 200 200 & 300 300 MeV/u

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p-A @300  ESPRI  rn(r) + rp(r) e-A  SCRIT  rch(r)  rn(r), rp(r)

Idea: energy dependences of pp & pn interaction

p-A @300  ESPRI  arn(r) + brp(r) p-A @200  ESPRI  crn(r) + drp(r)

10 1 10 2 10 3 10 100 1000 pp pn np

• Elab. [MeV]

Cross section [mb]

200 300 400

 Demonstration of the new method with Zr data

Simultaneous extraction from two- energy p-elastic data of 90,92,94Zr

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Fitting results of 90Zr @ 200 & 300 MeV Simultaneous search of

Neutron & Proton From 300 & 200 MeV data

Extracted densities of 90Zr

Unstable nuclei

• ESPRI project-

Elastic Scattering of Protons from RI beams Application to nuclei with large isospin asymmetry

ESPRI project

【nuclear chart】

: doubly magic nuclei process from 208Pb

208Pb@RCNP

132Sn@RIBF: This Spring

2016/11/22 10

66,70Ni

@GSI

9,10,11,16C

@HIMAC, RIBF

Elastic Scattering of Protons from RI beams Extension of proton elastic scattering method to unstable nuclei

48Ca@RCNP

ESPRI devices

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Drift Chamber Plastic scintillator Solid hydrogen target

1 mmt φ30 mm

Recoil Proton Spectrometer (RPS)

ESPRI devices

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θlab = 66° - 80°, Ep=20-120 MeV, ΔΩ〜10 msr/deg. q=1-2.2 fm-1, ΔEx = 400-500 keV Recoil drift chamber 436x436 mm2 (x-y-x’-y’-x’-y) Plastic scintillator 440x440 mm2 x 2 mmt NaI(Tl) calorimeter 431.8x45.72 mm2 x 50.8 mmt

Recoil Proton Spectrometer (RPS)

Light unstable nuclei : 9,10,11,12,16C

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Recoil proton energy (MeV)

11C 10C 9C 12C Preliminary 16C

Preliminary

(T. Baba)

# of analyzed beams

9C

0.5x109

10C

3x109

11C

5x109

12C

6x109

16C

7x109 Preliminary Preliminary

w/ Z=6 gated w/ Z=6 gated

Kinematical correlation : Tp vs qp

ESPRI

CAT

April – May 2016: RIBF113(CAT)@F8 & RIBF79(ESPRI)@F12 was performed in a parasitic way.

ESPRI experiment of 132

132Sn

Sn @ RIBF

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RI beam production Experimental Accelerators

238U@345

MeV/u ~20pnA

RIBF79R1 (ESPRI) / RIBF113 (CAT) Experiment in the parasitic mode

F7 F8 F12

CAT (ISGMR) 100 MeV/u 132Sn(d,d’) ESPRI (Skin thickness) 200 MeV/u 132Sn(p,p)

EXP (Beam time) CAT setup @F8 ESPRI setup @F12 RIBF113(CAT) in April

132Sn@ 100 MeV/u

(d, d’) GMR (d, d) elastic RIBF79R1 (ESPRI) in May

132Sn@ 200 MeV/u

(p, p’) GMR (p, p) elastic

2016/11/22 15

Proton elastic scattering of 132Sn successfully measured at RIBF

132Sn (p, p) at 200 MeV/u was measured in May 2016

: NP1512-RIBF79R1

[deg]

Proton energy by NaI [ch]

Proton tof [ch] 90 85 80 75 70 65

Online plot

Clear elastic event Recoil proton angle 1mmt solid hydrogen target

ESPRI detector setup

2016/11/22 16

Elastic Scattering of Protons with RI beams (ESPRI) project

RCNP I.Tanihata H.Jin Ong

• J. Tanaka

GSI S272 collaborators NIRS-HIMAC E.Takada M.Kanazawa RIKEN

• T. Uesaka

H.Takeda K.Ozeki K.Yoneda Tohoku Univ. T.Kobayashi Kyoto Univ. T.Kawabata T.Murakami M.Tsumura T.Furuno Miyazaki Univ. Y.Maeda CNS, Univ. of Tokyo

• S. Ota

Collaborators

• J. Zenihiro (RIKEN)

S.Terashima (Beihang Univ.) Y.Matsuda (Tohoku Univ. CYRIC) H.Otsu (RIKEN) H.Sakaguchi (RCNP)

2016/11/22 17

Summary

• Constraints on the symmetry energy parameters by neutron skin

thicknesses

• Proton elastic scattering method : rn(r)
• 204,206,208Pb
• Recent progress
• Stable nuclei
• double magic nuclei : 40,42,44,48Ca
• Simultaneous extraction of rp(r) & rn(r) from 200 & 300 MeV data :

90,92,94Zr

• Unstable nuclei
• ESPRI project : 9,10,11,16C, 20O, 66,70Ni
• Double magic nucleus : 132Sn  RIBF79R1 132Sn(p,p) @ 200MeV/u
• Future :
• ESPRI experiment of 132Sn @ 300 MeV/u
• Next target of ESPRI : 50,52Ca (magic ?)

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