58Ni(p, n)58Cu Ep = 160 MeV

58Ni(3He, t)58Cu E = 140 MeV/u

Cou

nts

Excitation Energy (MeV)0 2 4 6 8 10 12 14

Comparison of (p, n) and (3He,t) ０ o spectra

Y. Fujita et al.,EPJ A 13 (’02) 411.

H. Fujita et al.,PRC 75 (’07) 034310

J. Rapaport et al.NPA (‘83)

GTGR

*GT () : Important weak response, simple operator

Yoshitaka FUJITA (Osaka Univ.)

New Era of Nuclear Physics in the Cosmos RIKEN August 25-26, 2008

Nuclear Weak and EM Response Studied by Intermediate-energy Nuclear

Reactions (中間エネルギー核反応による原子核弱電磁応答）

-decay : absolute B(GT), but only low-lying states

(-induced reactions: no chance !) CE reaction : relative B(GT), but highly excited region

*GT () : Important weak response, simple operator

*E1 : Important electro-magnetic response (’) [NRF] : up to particle threshold (g, n) : above particle threshold inelastic SC. at 0o : Coulomb Ex. + Nucl. Ex.

Yoshitaka FUJITA (Osaka Univ.)

New Era of Nuclear Physics in the Cosmos RIKEN August 25-26, 2008

Nuclear Weak and EM Response Studied by Intermediate-energy Nuclear Reactions

( 中間エネルギー核反応による原子核弱電磁応答）

-decay : absolute B(GT), but only low-lying states

(-induced reactions: no chance !) CE reaction : relative B(GT), but highly excited region

mainly by &

Langanke & Martinez-PinedoRev.Mod.Phys.75(’04)819

(A,Z)=nuclei in the　　　 Fe, Ni region

-decay, e-capture, -induced reactions

Balantekin & FullerJ.Phys.G 29(’03)2513

Crucial Weak Processesduring the

Core Collapse

Gamow-Teller (GT) transitions

Simulation of -decay spectrum

Direct Reactions with Light Projectiles

Projectile3He

Target

Coulomb Excitation

Elastic Scattering

Inelastic Scattering

Pick-up Stripping

Charge-exchange

Similarity with decay!by Berta Rubio

|i> |f>

-int.

Ejectile t

-decay & Nuclear Reaction

)GT(1 2

2/1

BKf

tGT -decay tra. str. =

B(GT) : reduced GT transition strength

(matrix element)2

*Nuclear (CE) Reaction Cross-section= reaction mechanism x operator x structure =(matrix element)2

A simple reaction mechanism should be achieved ! we have to go to high incoming energy

-decay & Nuclear Reaction

)GT(1 2

2/1

BKf

tGT -decay strength =

B(GT) : reduced GT transition strength

(matrix element)2

*Nuclear (CE) Reaction cross-section= reaction mechanism x operator x structure =(matrix element)2

A simple reaction mechanism should be achieved ! we have to go to high incoming energy

Study of Weak Response of Nucleiby means of

Strong Interaction !using -decay as a reference

***Derivation of B (GT) strength***

B (GT) derivation

Nucleon-Nucleon Int. : Ein dependence at q =0

V

V

V

V

central-type interactionsSimple one-step reaction mechanism

at intermediate energies!

Energy/nucleon

Str

engt

h

Love & Franey PRC 24 (’81) 1073

N.-N. Int. : & Tensor- q-dependence

Tlargest at q=0 !larger than others !

Love & Franey PRC 24 (’81) 1073

B (GT) derivation

58Ni(p, n)58Cu Ep = 160 MeV

58Ni(3He, t)58Cu E = 140 MeV/u

Cou

nts

Excitation Energy (MeV)0 2 4 6 8 10 12 14

Comparison of (p, n) and (3He,t) ０ o spectra

Y. Fujita et al.,EPJ A 13 (’02) 411.

H. Fujita et al.,PRC 75 (’07) 034310

J. Rapaport et al.NPA (‘83)

GTGR

**Connection between-decay and (3He,t) reaction**

by means of Isospin

Nucleon & Coin

= Coin

back front

= Nucleon

isospin T=1/2, 3/2, …Tz=1/2 Tz= -1/2

2714

Si1327

13Al14Tz = (1/2)N + (-1/2)Z*z-component: conserved

Nuclei & Coin

= Coin

back front

= Nuclei

isospin T=1 triplet

2612Mg14

Tz= +1 Tz= -1

2614Si12

Tz= 0

2613Al13

Symmetry in1) structure2) transitions

Transitions in real & isospin space (T=1)

Tz=+1

58Ni

0+

1+

Tz=0

58Cu

0+

1+

1+

1+

1+ Tz=-1

58Zn

0+

1+

, IASQEC=9.37

QEC=8.56

Symmetry Transitions from T=1 Nuclei Tz=+1 Tz=0 Tz=-1

(in real energy space)

-decay

1+

(stable)

(p,n)-type

Tz=+1 Tz=-1Tz=0

58Ni 58Cu 58Zn

0+ 0+0+

1+

1+1+

1+

1+

1+

1+

(p,n)-typeV

-decay

V

Symmetry Transitions from T=1 Nuclei Tz=+1 Tz=0 Tz=-1

(in isospin symmetry space*)

V

, IAS

*after the correction of Coulomb displacement energy

2612Mg14

2614Si12

2613Al13

Tz=-1

Tz= 0

Tz=+1

26MgZ=12, N=14

26AlZ=13, N=13

26SiZ=14, N=12

T=1 symmetry : Structures & Transitions

26Mg(p, n)26Al & 26Mg(3He,t)26Al spectraR. Madey et al.,PRC 35 (‘87) 2001

Y. Fujita et al.,PRC 67 (‘03) 064312

Prominent states are GT states and the IAS !

IAS

, 0+

B(GT) values from Symmetry Transitions (A=26)

Y. Fujita et al., PRC 67 (‘03) 064312

-decay (3He,t)

26Mg(3He,t) spectra

26Mg(3He,t) spectra

Relationship: Decay and Width

Heisenberg’s Uncertainty Priciple

Et

px

Width E *if: Decay is Fast, then: Width of a State is Wider !*if t =10-20 sec E ~100 keV (particle decay t =10-15 sec E ~ 1 eV (fast decay)

Importance of Isospin : in p-decay of 26Al

+Proton

26Al25Mg + proton

p pn n

decay

Tz : 1/2 + (-1/2) = 0

T : 1/2 + 1/2 = 0 or 1 3/2 + 1/2 = 1 or 2

#T=3/2 state in 25Mg : Ex > 7.79 MeV #Sp (p-sep. energy) in 26Al : 6.31 MeV

for T = 0, 1 states : Ex = 6.31 MeVeffective Sp in 26Al

for T = 2 states : Ex = 14.1 MeV

26Mg(3He,t) spectra

Information on:•Excitation Energy•Transition Strength•Decay Width

B(GT) values from Symmetry Transitions

(A=34)normalized

Y. Fujita et al.,PRC 75 (’07)

057305

High-resolution Experiment

-beam matching techniques-（ dispersion matching

techniques)

RCNP Ring Cyclotron

Good quality 3He beam (140 MeV/nucleon)

Grand Raiden Spectrometer

Large AngleSpectrometer

3He beam

(3He, t) reaction

Beam line WS-course at RCNPT. Wakasa et al., NIM A482 (’02) 79.

Dispersion Matching Techniques

Matching Techniques

RCNP, Osaka Univ.

Dispersion Matching Techniques were applied!

E=150 keV

E=30 keV

Supernova Cycle

important

Langanke & Martinez-PinedoRev.Mod.Phys.75(’04)819

(A,Z)=nuclei in theCr, Mn, Fe, Co, Ni region pf -shell Nuclei !

Crucial Weak Processesduring the

Core Collapse

Balantekin & FullerJ.Phys.G 29(’03)2513

GT strengths in A=42-58

GT-GR

**Derivation of “absolute” B(GT) values

-decay: T1/2 and absolute B(GT) values but only for the low-lying states

*(3He,t) reaction: highly-excited states can be accessed but only the relative B(GT) values

Let’s combine these data !

Mirror nuclei

46Ti

50Cr

54Fe50Fe

54Ni

46Cr

ß+

(3He,t)

N=Z

T=1 Isospin Symmetry in pf-shell Nuclei

5428Ni26

5426Fe28

T z=0

T z=1

T z=-1

LeuvenValencia

SurreyOsaka

GSIby B. Rubio

Nuclei & Coin

= Coin

back front

= Nuclei

isospin T=1 triplet

5024Cr26

Tz= +1 Tz= -1

5026Fe24

Tz= 0

5025Mn25

Isospin Symmetry Transitions: 50Cr(3He,t) 50Mn -decay 50Fe

QEC=8.152(61) MeVT1/2=0.155(11) s

0.651

(Z,N)= (24,26) (25,25) (26,24)

B(GT)=0.60

**Reconstruction of decay from (3He,t)

---assuming isospin symmetry ---

Simulation of -decay spectrum

relative intensities of-decay feeding are deduced !

Y. Fujita et al. PRL 95 (2005)

Absolute B(GT) values-via reconstruction of -decay spectrum-

GTi

iFermi ttT111

2/1

-decay experiment

T1/2=0.155(11) s

it/1hTra.Streng

GT tra. to the 0.65 MeV stateNew value B(GT)=0.50(13)

*20% smaller than deduced in the -decay: 0.60(16)

Absolute intensity: B(GT)

Y. Fujita et al.PRL 95 (2005)

B(F)=N-Z Relative feeding intensity from (3He,t)

ti =partial half-life

Mirror nuclei

46Ti

50Cr

54Fe50Fe

54Ni

46Cr

ß+

(3He,t)

N=Z

T=1 Isospin Symmetry in pf-shell Nuclei

5428Ni26

5426Fe28

T z=0

T z=1

T z=-1

LeuvenValencia

SurreyOsaka

GSICNSby B. Rubio

54Ni -decay measurement

54Ni

Sp =4.35

Q =8.800

+ decay

0+

0.937

g.s. IAS

•at Louvain la Neuve (ISOL facility)•at GSI (FRS facility)

T1/2=0.115(4) s

Absolute B(GT) values in 54Ni -decay-via reconstruction of -decay spectrum-

GTi

iFermi ttT111

2/1

-decay exp.at LLN (Belgium)T1/2=0.115(4) s

New value B(GT)=0.46(8)

Absolute intensity: B(GT)

B(F)=N-Z Relative feeding intensity from (3He,t)

ti =partial half-life

B(GT) : 1st 1+ state at 0.937 MeV

*old -decay value : 0.68(16) (assuming no higher Ex states)

*54Fe(p,n)54Co value : 0.74(5)

it/1hTra.Streng

54Ni -decay measurement

54Ni

Sp =4.35

Q =8.800

+ decay

0+

0.937

g.s. IAS

•at Louvain la Neuve (ISOL facility)•at GSI (FRS facility)

Accurateratio of -ray

intensity

GSI: RISING set up- active stopper campaign -

3-layors of DSSD active stopper

FRS

GSI RISING set up

Active Beam Stopper CampaignJuly-August, 2007

RCNP, Osaka

(b)

(a)

RISING, GSI

RC

NP

, Osa

ka

RIS

ING

, GS

I

B(GT)

(3He,t)

0.46 0.48

0.07 0.07

0.09 0.07

B(GT)

-decay

Comparison

*B(GT) values using

T1/2=115 ms（ Louvain)

Mirror nuclei

48V

52Mn

56Co52Co

56Cu

48Mn+

(3He,t)

N=Z

T = 2 Isospin Symmetry in pf-shell Nuclei

5228Ni24

5224Cr28

T z=0

T z=1

T z=-1

52Ni

T z=2

T z=-2

52Cr48Cr

52Fe

56Ni

56Fe

56Zn

48Ti

48Fe

by Y. Fujita, B. Rubio

How is the T1/2 value?

Comparison: (p, n) and (3He,t)IAS

g.s.

52Cr(p, n)52MnEp =120 MeV

D. Wang et al., NP A480 (’88) 285

-decay simulation

x R2/2 for IAS(correction of coupling constant)

f-factor

-decay Half-life T1/2

-via reconstruction of -decay spectrum-

GTi

iFermi ttT111

2/1

abs. B(GT) distributionfrom (3He,t)

B(F)=N-Z

it/1hTra.Streng

52Ni -decay Half-life T1/2

GTi

iFermi ttT111

2/1

-decay exp. (C. Dossat et al., NPA 792, 18 ’07 )

T1/2= 40.8(2) ms GANILabs. B(GT) distribution

[52Cr(3He,t)]QEC=11.88 MeV

[-decay + IMME (‘06)]

B(F)=N-ZIsospin symmetry estimation

T1/2= 39 (3) ms

SM cal. (PRC 57, 2316, ’98)

T1/2= 50 msMass formula (T. Tachibana et al.)

T1/2= 35 ms

Uncertainty of the Q-value should still be considered !

it/1hTra.Streng

The Layer Structure of Nature(Snake of Uroboros)

What are other connectionsbetween the world of

Nuclear Physics & Astrophysics?

E1 Coulomb Excitation

dipoleexcitation

E1-distribution: Low-lying & GDR

Low-lying region: studied by (’) [NRF]

Higher-Ex region: studied by (n)

Gent data

Livermore data

58Ni(, ’)

58Ni(n)

6 8

Livermore data

58Ni(p, p’), 160 MeV at 0o

Livermore data58Ni(n)

8

(p, p’) & (, n)

IUCF data

26Mg(, ’)FZR NRF data

26Mg(p, p’)

A. Tamii et al..RCNP

26Mg(p, p’) & E1

Good proportionality !

E-field: Time dependence•Emax= z1e

•Intensity dI()/d|max

= (c/2)(z1e)2

•(p, p’) 300 MeV =1.3, z=1 Intensity=1.69(c/2p)e2

•(3He,3He’) 160 MeV/u g=1.17, z=2 Intensity=5.48(c/2)e2

Summary* Weak response of Nuclei was studied by using Strong Int.

--Charge Exchange Reaction--

* Isospin Symmetry was introduced.

* High resolution of the (3He,t) reaction

allowed the comparison of analogous transitions

* Absolute B(GT) strengths were derived.

* High resolution (p, p’) and/or (3He,3He’)

allows the study of B(E1) strengths.

Collaboration of Experimentalists and Theorists is very important!

High-Resolution Collaborations

Bordeaux (France) : decayGANIL (France) : decayGent (Belgium) : (3He, t), (d, 2He), (’), theoryGSI, Darmstadt (Germany) : decay, theoryISOLDE, CERN (Switzerland) : decayiThemba LABS. (South Africa) : (p, p’), (3He, t)Jyvaskyla (Finland) : decayKoeln (Germany) : decay, (3He, t), theoryKVI, Groningen (The Netherlands) : (d, 2He)Leuven (Belgium) : decayLTH, Lund (Sweden) : theoryOsaka University (Japan) : (p, p’), (3He, t), theorySurrey (GB) : decayTU Darmstadt (Germany) : (e, e’), (3He, t)Valencia (Spain) : decayMichigan State University (USA) : theory, (t, 3He)Muenster (Germany) : (d, 2He), (3He,t)Univ. Tokyo and CNS (Japan) : theory, decay