# Presentation: 096568

## The 3rd LACM-EFES-JUSTIPEN Workshop 

**Yoshitaka FUJITA (Osaka Univ.)****	**** **
**The 3****rd**** LACM-EFES-JUSTIPEN Workshop**
**               ****ORNL      ****February 23-25, 2009**

_**Combining **__****__**-decay and Reaction **__**for Nuclear Structure studies**__** **_

-  -decay : absolute *B*(GT), but only low-lying states
-  CE reaction : relative *B*(GT), but highly excited region

## The 3rd LACM-EFES-JUSTIPEN Workshop 

- *Measurement of -rays after the -decay (delayed-)
-    is useful for :

-  half-life determination
-  -decay branching ratio

**Yoshitaka FUJITA (Osaka Univ.)****	**** **
**The 3****rd**** LACM-EFES-JUSTIPEN Workshop**
**               ****ORNL      ****February 23-25, 2009**

_**Combining **__****__**-decay and Reaction **__**for Nuclear Structure studies**__** **_

-  -decay : absolute *B*(GT), but only low-lying states
-  CE reaction : relative *B*(GT), but highly excited region

- CE reaction  isospin symmetry  delayed-measurement

## -decay & Nuclear Reaction

- -decay GT tra. rate =

*B*(GT) : reduced GT transition strength

- (matrix element)2

- *Nuclear (CE) reaction rate (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

## Direct Reactions with Light Projectiles

- Projectile
- 3He

- Target

- Coulomb Excitation

- Elastic Scattering

- Inelastic Scattering

- Pick-up

- Stripping

- Charge-exchange

- Similarity with  decay!

- by Berta Rubio

- |i>  |f>

- -int.

- Ejectile *t*

## N.-N. Int. :  & Tensor-   q-dependence

- 

- T

- largest at *q*=0 !
- larger than others !

- Love & Franey PRC 24 (’81) 1073

## 58Ni(p, n)58Cu

**58****Ni(*****p*****, *****n*****)****58****Cu**
**            ****E****p**** = 160 MeV**

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

- Counts

- Excitation Energy (MeV)

- 0           2          4           6           8          10        12         14

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

- Y. Fujita et al.,
- EPJ A 13 (’02) 411.
- H. Fujita et al.,
- PRC 75 (’07) 034310

- Sp

- J. Rapaport et al.
- NPA (‘83)

- T> states

- GTGR

- At such high energy & at 0o,
- it was found that
- GT excitations are dominant!

## -decay & Nuclear Reaction

- -decay GT tra. rate =

*B*(GT) : reduced GT transition strength

- (matrix element)2

- *Nuclear (CE) reaction rate (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

## Simulation of -decay spectrum

- Simulation of -decay spectrum

## 58Ni(p, n)58Cu

**58****Ni(*****p*****, *****n*****)****58****Cu**
**            ****E****p**** = 160 MeV**

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

- Counts

- Excitation Energy (MeV)

- 0           2          4           6           8          10        12         14

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

- CE-reactions gives
- only relative B(GT) values!
- Absolute values from
- -decay are needed!

## -decay & Nuclear Reaction

- -decay GT tra. rate =

*B*(GT) : reduced GT transition strength

- (matrix element)2

- *Nuclear (CE) reaction rate (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 Nuclei
- by means of
- Strong Interaction !
- using -decay as a reference

## **Connection between-decay and (3He,t) reaction**by means of Isospin Symmetry

## T=1 Isospin Symmetry

- Byodoin-temple
- Uji, Kyoto
- 宇治・平等院

## Nuclei & Coin

- = Coin

- back                     front

- = Nuclei

- isospin T=1 triplet

- 2612Mg14

- Tz= +1

- Tz= -1

- 2614Si12

- Tz= 0

- 2613Al13

- Symmetry in
- structure
- transitions

## Transitions in real & isospin space (T=1)

- 2612Mg14

- 2614Si12

- 2613Al13

- Tz=-1

- Tz= 0

- Tz=+1

## T=1 symmetry : Structures & Transitions

- 26Mg
- Z=12, N=14

- 26Al
- Z=13, N=13

- 26Si
- Z=14, N=12

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

- Y. Fujita et al., PRC 67 (‘03) 064312

- -decay

-  (3He,t)

## B(GT) values from Symmetry Transitions (A=34)

- normalized

- Y. Fujita et al.,
- PRC 75 (’07)
- 057305

## 58Ni(p, n)58Cu

**58****Ni(*****p*****, *****n*****)****58****Cu**
**            ****E****p**** = 160 MeV**

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

- Counts

- Excitation Energy (MeV)

- 0           2          4           6           8          10        12         14

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

## High-resolution Experimentat RCNP, Osaka-beam matching techniques-(dispersion matching techniques)

## RCNP Ring Cyclotron

- Good quality 3He beam (140 MeV/nucleon)

## Grand Raiden Spectrometer

- Large Angle
- Spectrometer

- 3He beam

- (3He, t) reaction

## RCNP, Osaka Univ.

- Dispersion Matching Techniques
- were applied!

- E=150 keV

- E=30 keV

## Supernova Cycle

- rp-process

- -induced
- CE reaction

## GT strengths in A=42-58

- GT strengths in A=42-58

- GT-GR

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

- -decay:  1/2 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 !

***T***

## T=1 Isospin Symmetry in pf-shell Nuclei

- 46Ti

- 50Cr

- 54Fe

- 50Fe

- 54Ni

- 46Cr

**ß+**

- (3He,t)

- N=Z

- T=1 Isospin Symmetry in *pf*-shell Nuclei

- 5428Ni26

- 5426Fe28

- Tz=0

- Tz=1

- Tz=-1

- Leuven
- Valencia
- Surrey
- Osaka
- GSI

- by 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) MeV
- T1/2=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

- 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-

- -decay experiment
- T1/2=0.155(11) s

- GT tra. to the 0.65 MeV state
- New 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)

*t**i* =partial half-life

## T=1 Isospin Symmetry in pf-shell Nuclei

- 46Ti

- 50Cr

- 54Fe

- 50Fe

- 54Ni

- 46Cr

**ß+**

- (3He,t)

- N=Z

- T=1 Isospin Symmetry in *pf*-shell Nuclei

- 5428Ni26

- 5426Fe28

- Tz=0

- Tz=1

- Tz=-1

- Leuven
- Valencia
- Surrey
- Osaka
- GSI
- CNS

- by B. Rubio

## T1/2

- 54Ni -decay measurement

- 54

- Ni

- S

- p

- =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-

- -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)

*t**i* =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)

## 54Ni -decay measurement

- 54Ni -decay measurement

- 54

- Ni

- S

- p

- =4.35

- Q

- =8.800

****

- +

- decay

- 0

- +

- 0.937

- g.s. IAS

- at Louvain la Neuve
-      (ISOL facility)

- at GSI
-      (FRS facility)

- Accurate
- ratio of
- -ray
- intensity

## GSI: RISING set up- active stopper campaign -

- GSI: RISING set up- active stopper campaign -

- 3-layors of DSSD active stopper

- FRS

## GSI  RISING set up

- Active Beam Stopper Campaign
- July-August, 2007

## (b)

**RCNP, Osaka**

- (a)

**RISING, GSI**

## Comparison

**RCNP, Osaka**

**RISING, GSI**

**B(GT)**** **
**(****3****He,t)**

**0.46**

**0.48**

**0.07**

**0.07**

**0.09**

**0.07**

**B(GT)**** **
******-decay**

- *B(GT) values
- using
- T1/2=115 ms
- (Louvain)

## 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
- * -delayed -decay measurement is important.
- * *B*(*E*1) values can be derived from (p, p’) measurements.

## High-Resolution Collaborations

- Bordeaux (France) :  decay
- GANIL (France) :  decay
- Gent (Belgium) : (3He, t), (d, 2He), (’), theory
- GSI, Darmstadt (Germany) :  decay, theory
- Istanbul (Turkey) :  decay, (3He,t)
- iThemba LABS. (South Africa) : (p, p’), (3He, t)
- Jyvaskyla (Finland) :  decay
- Koeln (Germany) :  decay, (3He, t), theory
- KVI, Groningen (The Netherlands) : (d, 2He)
- Leuven (Belgium) :  decay
- LTH, Lund (Sweden) : theory
- Osaka University (Japan) : (p, p’), (3He, t), theory
- Surrey (GB) :  decay
- TU Darmstadt (Germany) : (e, e’), (3He, t)
- Valencia (Spain) :  decay
- Michigan State University (USA) : theory, (t, 3He)
- Muenster (Germany) : (d, 2He), (3He,t)
- Notre Dame (USA) : transfer reactions
- Univ. Tokyo and CNS (Japan) : theory,  decay