[PPT] - Breakup Reactions of Breakup Reactions of Halo Nuclei Halo Nuclei PowerPoint Presentation

SLIDE 1

Breakup Reactions of Breakup Reactions of Halo Nuclei Halo Nuclei

T. Sugimoto
T. Sugimoto a),

a),*

*, , T. Nakamura

T. Nakamura a)

a),

, N. Fukuda

N. Fukuda b)

b),

, M. Miura

M. Miura a)

a),

,

Y. Kondo
Y. Kondo a)

a),

, N. Aoi

N. Aoi b)

b),

, H. Baba

H. Baba c)

c),

, D. Bazin

D. Bazin d)

d),

, T. Gomi

T. Gomi c)

c),

,

H. Hasegawa
H. Hasegawa c)

c),

, Y. Hashimoto

Y. Hashimoto a)

a),

, N. Imai

N. Imai b)

b),

, T. Kobayashi

T. Kobayashi e)

e),

,

T. Kubo
T. Kubo b)

b),

, T. Motobayashi

T. Motobayashi b)

b),

, M. Ohara

M. Ohara a)

a),

, A. Saito

A. Saito c)

c),

,

H. Sakurai
H. Sakurai f)

f),

, S. Shimoura

S. Shimoura g)

g),

, A. M. Vinodkumar

A. M. Vinodkumar a)

a),

,

K. Watanabe
K. Watanabe e),

e), Y. X. Watanabe

Y. X. Watanabe h)

h),

, T. Yakushiji

T. Yakushiji e)

e),

,

Y. Yanagisawa
Y. Yanagisawa b)

b),

, K. Yoneda

K. Yoneda d)

d),

, and M. Ishihara and M. Ishihara b)

b)

a) Tokyo Institute of Technology b) RIKEN c) Rikkyo Universi a) Tokyo Institute of Technology b) RIKEN c) Rikkyo University ty d) NSCL, Michigan State University e) Tohoku University f) U d) NSCL, Michigan State University e) Tohoku University f) University of Tokyo niversity of Tokyo g) CNS, University of Tokyo h) High Energy Accelerator Researc g) CNS, University of Tokyo h) High Energy Accelerator Research Organization h Organization

SLIDE 2

Neutron Halo Nuclei Neutron Halo Nuclei

11 11Li

Li

14 14Be

Be

17 17B

B

Two Neutron Halo ( (11

11Li :

Li : 9

9Li +

Li + n n + + n n) ) Borromean Ring ( (11

11Li :

Li : 9

9Li +

Li + n n + + n n) )

9 9Li

Li n n n n Our Our Interest Interest two neutron halo nuclei: two neutron halo nuclei: 11

11Li,

Li, 14

14Be,

Be, 17

17B

B

and these subsystems: and these subsystems: 10

10Li,

Li, 13

13Be,

Be, 16

16B

B

SLIDE 3

Previous Works Previous Works

M. Thoennessen et al., Phys. Rev. C
M. Thoennessen et al., Phys. Rev. C 59

59, 111 (1999) , 111 (1999)

Comparison of the Decay Energy of Comparison of the Decay Energy of 10

10Li

Li

Reported Levels of Reported Levels of 13

13Be

Be

M. Thoennessen et al., Phys. Rev. C
M. Thoennessen et al., Phys. Rev. C 63

63, 014308 (2000) , 014308 (2000)

Reported Levels of Reported Levels of 16

16B

B

R. Kalpakchieva et al., Eur. Phys. J. A
R. Kalpakchieva et al., Eur. Phys. J. A 7

7, 451 (2000) , 451 (2000)

0.04(4) 0.04(4) 2.32(7) 2.32(7)

10 10Li

Li : results are not matched yet. : results are not matched yet.

13 13Be,

Be, 16

16B

B : only a few results are reported. : only a few results are reported. Systematic study of the Systematic study of the unbound subsystems unbound subsystems. .

SLIDE 4

Studies using Breakup Reactions Studies using Breakup Reactions

Carbon Target Carbon Target (small (small Z Z) ) —

— Nuclear Breakup Nuclear Breakup — —

Neutron Knockout Reaction

Li

9

p

neut

p

( )

∑ ∑ ∑

− = − =

fragment rel 2 2

* * M M E p E M

Invariant mass Invariant mass and and Relative energy Relative energy

the momentum vectors the momentum vectors of

f charged fragment

charged fragment and and one neutron

ne neutron

Invariant Mass Method Invariant Mass Method

Relative energy spectrum between core + neutron subsystem single particle state single particle state of

f the unbound subsystem

the unbound subsystem

→ → Energy level and Configuration of Energy level and Configuration of valence neutron valence neutron

SLIDE 5

F2 F1 F3

Q1 Q2 Q3 SX1

D1

SX2 Q4 Q5 Q6 SX3

D2

SX4 Q7Q8 Q9 Q10Q11Q12

F0

E6

Experimental Facility Experimental Facility — — RIPS RIPS

RI RIKEN KEN P Projectile rojectile-

Fragment

Fragment S Separator eparator

Primary Beam Primary Beam

11 11Li,

Li, 14

14Be :

Be : 18

18O 100 MeV/nucleon

O 100 MeV/nucleon

17 17B :

B : 22

22Ne 110 MeV/nucleon

Secondary Beam Secondary Beam Experimental Area Experimental Area

Ne 110 MeV/nucleon

Secondary Beam Secondary Beam

11 11Li : 69.0 MeV/nucleon,

Li : 69.0 MeV/nucleon, 11 kcps, 90% 11 kcps, 90%

14 14Be : 68.3 MeV/nucleon,

Be : 68.3 MeV/nucleon, 5.2 kcps, 90% 5.2 kcps, 90%

17 17B : 72.7 MeV/nucleon,

B : 72.7 MeV/nucleon, 700 cps, 85% 700 cps, 85%

Primary Beam Primary Beam Primary Target Primary Target

SLIDE 6

Experimental Setup Experimental Setup

PPAC Drift Chamber NaI(Tl) Dipole Magnet Drift Chamber Hodoscope Veto Counters Neutron Hodoscope (Plastic Scintillator)

Neutron(s Neutron(s) ) Secondary Beam Secondary Beam

11 11Li,

Li, 14

14Be, or

Be, or 17

17B

B

Charged Fragments Charged Fragments

9 9Li,

Li, 12

12Be,

Be, 15

15B,

B, … …

Secondary Target Secondary Target

C (377 mg/cm C (377 mg/cm2

2)

) Pb Pb (346 mg/cm (346 mg/cm2

2)

)

γ γ-

ray

ray

from charged particle from charged particle

RIPS F3 RIPS F3

Experimental Area Experimental Area

SLIDE 7

Relative Energy Spectrum of Relative Energy Spectrum of 9

9Li+

Li+n n

k r r r d dE d

k 2 * 3

) ( ) ( ~ Ψ ∫ ψ σ

(overlap integral) (overlap integral)

s s-

wave:

wave:

continuum state continuum state 10 10Li

Li

r r r r ) exp( ) , ( α − ∝ ′ Ψ

(initial state: (initial state: Yukawa function Yukawa function) )

kr kr r

k

) sin( ) ( δ ψ + =

(final state: (final state: scattering state scattering state) )

) ( 3 k O ak + − = δ

(phase shift) (phase shift)

c.f. M. Thoennessen et al. c.f. M. Thoennessen et al. s s-

wave:

wave: a a < < -

20 fm

20 fm p p-

wave:

wave: E Er

r = 0.538 MeV

= 0.538 MeV, , Γ Γ = 0.358 MeV = 0.358 MeV Fitting Parameters Fitting Parameters a a : scattering length : scattering length α α : ~ : ~√ √(2 (2µ µ S S2n

2n)

)

G. F. Bertsch and K. Hencken, Phys. Rev. C
G. F. Bertsch and K. Hencken, Phys. Rev. C 57

57, 1366(1998) , 1366(1998)

SLIDE 8

Relative Energy Spectrum of Relative Energy Spectrum of 12

12Be+

Be+n n

c.f. M. Thoennessen et al.: c.f. M. Thoennessen et al.: s s-

wave:

wave: a a < < -

10 fm

10 fm E E ~ 0.2 MeV ~ 0.2 MeV

13 13Be

Be

k r r r d dE d

k 2 * 3

) ( ) ( ~ Ψ ∫ ψ σ

(overlap integral) (overlap integral)

s s-

wave:

wave:

continuum state continuum state

r r r r ) exp( ) , ( α − ∝ ′ Ψ

(initial state: (initial state: Yukawa function Yukawa function) )

kr kr r

k

) sin( ) ( δ ψ + =

(final state: (final state: scattering state scattering state) )

) ( 3 k O ak + − = δ

(phase shift) (phase shift)

Fitting Parameters Fitting Parameters a a : scattering length : scattering length α α : ~ : ~√ √(2 (2µ µ S S2n

2n)

)

SLIDE 9

Relative Energy Spectrum of Relative Energy Spectrum of 15

15B+

B+n n

by Sugimoto et al. Er = 0.065 γ = 0.136 s-wave as a background

d d-

wave:

wave:

resonance state resonance state

4 ) ( ~

2 2 r

Γ + − Γ E E dE dσ

(Breit (Breit-

Wigner

Wigner eq eq.) .)

2

l l l

P γ = Γ (penetrability) (penetrability) (resonance width) (resonance width)

4 2 5 2

) ( ) ( 3 9 ) ( ) ( kR kR kR kR P

l

+ + =

=

16 16B

B

Fitting Parameters Fitting Parameters E Er

r : resonance energy

: resonance energy γ γ : reduced width : reduced width A low A low-

lying

lying d d-

state is observed.

state is observed. E Er

r = 0.07 MeV,

= 0.07 MeV, γ γ = 0.14 = 0.14 c.f. c.f. R. Kalpakchieva et al.:

R. Kalpakchieva et al.: E

E = 0.04(6) MeV = 0.04(6) MeV

SLIDE 10

Further Analysis: Three Further Analysis: Three-

body Relative Energy

body Relative Energy

Three Three-

body

body Invariant Invariant-

mass

mass

Lead Target Lead Target: :

Coulomb Breakup Coulomb Breakup

P r e l i m i n a r y P r e l i m i n a r y

11 11Li

Li

Low Low-

lying

lying E1 strength E1 strength

SLIDE 11

Summary Summary

Studies of

Studies of 11

11Li,

Li, 14

14Be, and

Be, and 17

17B,

B, using the using the Nuclear Breakup Nuclear Breakup reaction reaction

Investigation of the

Investigation of the single particle state single particle state

f unbound subsystems (
f unbound subsystems (10

10Li,

Li, 13

13Be,

Be, 16

16B)

B)

Invariant

Invariant-

mass Spectroscopy

mass Spectroscopy

10

10Li,

Li, 13

13Be :

Be : s s-

wave continuum state

wave continuum state

16 16B :

B : d d-

wave resonance state

wave resonance state — — a a candidate candidate of the ground state

f the ground state
Further analysis:

Further analysis: Three Three-

body Relative Energy

body Relative Energy with Nuclear / Coulomb Breakup reactions with Nuclear / Coulomb Breakup reactions

SLIDE 12

Collaborators Collaborators

Tokyo Institute of Technology Tokyo Institute of Technology

T. Nakamura, M. Miura, Y. Kondo , A. M. Vinodkumar,
T. Nakamura, M. Miura, Y. Kondo , A. M. Vinodkumar,
Y. Hashimoto, M. Ohara
Y. Hashimoto, M. Ohara

RIKEN RIKEN

N. Fukuda, N. Aoi, N. Imai, T. Kubo, T. Motobayashi,
N. Fukuda, N. Aoi, N. Imai, T. Kubo, T. Motobayashi,
Y. Yanagisawa, M. Ishihara
Y. Yanagisawa, M. Ishihara

Rikkyo University Rikkyo University

H. Baba, T. Gomi, H. Hasegawa, A. Saito
H. Baba, T. Gomi, H. Hasegawa, A. Saito

NSCL, Michigan State University NSCL, Michigan State University

D. Bazin, K. Yoneda
D. Bazin, K. Yoneda

Tohoku University Tohoku University

T. Kobayashi, K. Watanabe, T. Yakushiji
T. Kobayashi, K. Watanabe, T. Yakushiji

University of Tokyo University of Tokyo

H. Sakurai, S. Shimoura
H. Sakurai, S. Shimoura

High Energy Accelerator Research Organization (KEK) High Energy Accelerator Research Organization (KEK)

Y. X. Watanabe
Y. X. Watanabe