The 11th Inter. Conf. on nucleus-Nucleus Collision, San Antonio Texas, May 27- June 1

Yu-Hu ZhangInstitute of Modern Physics, Chinese Academy of Sciences

Lanzhou, China

May 30. 2012, San Antonio Texas, USA

Test of IMME in fp shell via direct mass measurements of TZ = -3/2 nuclides

1. Introduction2. Mass measurements in CSRe3. Results & Discussion4. Conclusions

Outline

The 11th Inter. Conf. on nucleus-Nucleus Collision, San Antonio Texas, May 27- June 1

1. IntroductionWhat is IMME ? (Isobaric Multiplet Mass Equation)

N = Z

T=3/2 quartet

- 3/2

g.s

- 1/2

IAS

+ 1/2

IAS

+ 3/2

g.s

Neutron

Prot

on

(A,T,J)

Degenerate if nocharge-dependentInteraction, and nH

corrected for.

- 3/2 - 1/2 + 1/2 + 3/2

Charge-dependenteffects

M(A,T,T3)=a(A,T)+b(A,T)T3+c(A,T)T32

Any charge-dependent effects are two body interactions and be regarded as a perturbation.

+ d(A,T)T33 or

+ e(A,T)T34

33

2333 ),(),(),(),,(),,( TATdTATcTATbATaTATM

Test the IMME: the case of A=33,T=3/2

Breakdown of the Isobaric Multiplet Mass Equation at A= 33, T=3/2F. Herfurth, PhysRevLett.87.142501(2001)

Breakdown of the Isobaric Multiplet Mass Equation at A= 33, T=3/2F. Herfurth,1,3,* J. Dilling,1 A. Kellerbauer,2,5 G. Audi,4 D. Beck,6,1 G. Bollen,3,8 H.-J. Kluge,1 D. Lunney,4DOI: 10.1103/PhysRevLett.87.142501(2001)

Revalidation of the Isobaric Multiplet Mass EquationM. C. Pyle,1 A. García,1 E. Tatar,1 J. Cox,1 B. K. Nayak,1 S. Triambak,1 B. Laughman,1 A. Komives,1 L. O. Lamm,1DOI: 10.1103/PhysRevLett.88.122501 (2002)

Masses of 32Ar and 33Ar for Fundamental TestsK. Blaum,1,2,* G. Audi,3 D. Beck,2 G. Bollen,4 F. Herfurth,1 A. Kellerbauer,1 H.-J. PhysRevLett.91.260801 (2003)

PHYSICAL REVIEW C 73, 054313 (2006)Mass of the lowest T = 2 state in 32S: A test of the isobaric multiplet mass equationS.Triambak, A.Garcia, E.G.Adelberger, G.J.P.Hodges, D.Melconian, H.E.Swanson, S.A.Hoedl, S.K.L.Sjue, A.L.Sallaska, H.Iwamoto S.Triambak, A.Garcia, E.G.Adelberger, G.J.P.Hodges, D.Melconian, H.E.Swanson, S.A.Hoedl, S.K.L.Sjue, A.L.Sallaska, H.Iwamoto

Related publications

Test the IMME in pf Shell

N=Z

f7/2

CSRe

SFC (K=69)10 AMeV (H.I.), 17~35 MeV (p)

SSC(K=450) 100 AMeV (H.I.), 110 MeV (p)

CSRm 1000 AMeV (H.I.), 2.8 GeV (p)

RIBLL1RIBs at tens of AMeV

RIBLL2RIBs at hundreds of AMeV

HIRFL 能够提供不同能量、种类众多的稳定核束流和放射性核束流

2. Mass measurements in CSRe

Injection ToF

v

vqmqm

TT

tt

2

2

2 11

ref

reft BBd

CdC)()(

2

Principle of mass measurement in CSRe

Injection ToF

v

vqmqm

TT

tt

2

2

2 11

Principle of mass measurement in CSRe

Isochronous Mass Spectrometry (IMS mode)

t

DT

Detector

HIRFL−CSR

Injection ToF

v

vqmqm

TT

tt

2

2

2 11

t vv

t

2

2

1

Mass measurement in CSRe (IMS mode)

Ions Identification

Exp.

Simultion.

P2

Procedure of Data analysis

Signals in Oscilloscope

V-43

Mn-

47

Fe

-49

N

i-53

C

u-55

58Ni beam: Revolution Time Spectrum

58Ni beam: Revolution Time SpectrumSum of 760 sub-spectra, each of which includes spills

34Ar, 51Co: same m/q

Ion-amplitude identification: 51Co

21( )

1

n

iT T

STDEVn

Nuclides for Calibration:

Nuclides used for M/Q calibration are within a time window which is not far

from the isochronous condition.

M/q = a ＋ b T +c T 2 + d T 3

Xn =1.18

Mass excesses for the nuclides of interest (58Ni beam)

Tz=-1/

2, ( 7

8 Kr Bea

m)

Tz= -1

, -3/2,

( 58 Ni B

eam)

3. Results and Discussion

Mass excesses for the nuclides of interest (58Ni beam)

N=Z

?

?

?

?

Test the IMME in fp shell nucleiM(A,T,T3)=a(A,T)+b(A,T)T3+c(A,T) T3

2 + d(A,T)T33

33

2333 ),(),(),(),,(),,( TATdTATcTATbATaTATM

d coeficients increase gradually up to A=53 for which d is 3.5 deviated from zero.

Test the IMME in fp shell nuclei

Shell model calculations

53Mn gs 53Ni gs 53Fe IAS 53Co IAS

Mass Excesses uncertainty: 0.6 keV 25 keV 3. 4 keV 19 keV

More attention should be paid to the excitation Energies of IAS’s in 53Co & 53Fe since the errorsare three times as important as those of the g.s masses of 53N and 53Mn for an evaluation of d &in checking the validity of the IMME.

4. Conclusions

1) CSRe IMS + interpolation Masses of T3= -3/2 nuclei measured.

2) Breakdown of quadratic form of IMME found for A=53, T=3/2 quartet

3) More precise mass measurements of (53Ni; gs) and (53Co; IAS) are needed in order to check the validity of IMME in the pf shell.

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