C.M. Petrache University Paris-Sud & CSNSM Orsay

(Centre de Sciences Nucléaires et Sciences de la Matière)

1. Wobbling in Lu-Ta nuclei2. Transverse wobbling in 135Pr3. Transverse wobbling in 138Nd 4. Future plans and perspectives

The wobbling mode in A ~ 130 nuclei

163Lu

nwobb

=1

163Lu

nwobb

=2

nwobb

=1

165Lu

nwobb

=2

nwobb

=1

167Ta

nwobb

=1

Frauendorf and Dönau, PRC 89 (2014)

Wobbling frequency

ωwobb

increases with J => simple wobbler

ωwobb

decreases with J => transverse wobbler

Wobbling frequency is experimentally defined by:

Ewobb

= E (I, nw=1) – ½ [E (I+1, n

w=0) + E (I-1, n

w=0)]

Frauendorf and Dönau, PRC 89 (2014)

Wobbling mode

Longitudinal wobbling

Transverse wobbling

ωwobb

increases with J

ωwobb

decreases with J

Fitted QTR MoI for 135Pr

TAC MoI for 135Pr

RPA MoI for 138Nd

Simple wobbler (even-even)

Longitudinal wobblerTransverse wobbler

Longitudinal wobber Transverse wobber

jp

R

J

J

short

long

medium

135Pr

Frauendorf and Dönau, PRC 89 (2014)

163Lu

Frauendorf and Dönau, PRC 89 (2014)

6059

5857

56

55

60 Nd 59 Pr 58 Ce 57 La 56 Ba 55 Cs

50 82

138Nd66

50

64 66 68

N=ZWobbling in A=130-140 nuclei

135Pr

136Nd

135Pr120Sn(19F,4n)

135Pr

135Pr123Sb(16O,4n)

123Sb(16O,4n)

135Pr

135Pr

CNS calculations for CNS calculations for 138138NdNd

I. RagnarssonI. Ragnarsson

ππ h h11/211/2 νν h h11/211/2

X-axis 90X-axis 9000Z-axis 0Z-axis 000

E2 bandsE2 bands

TAC, CSMTAC, CSMS. FrauendorfS. Frauendorf

C. Petrache et al., C. Petrache et al., PRC 91, (2015)PRC 91, (2015)

138138NdNd

15 high-spin bands15 high-spin bands

γ γ < 0< 000

γ > γ > 0000

C. Petrache et al., PRC(R) 2013C. Petrache et al., PRC(R) 2013

Switch of rotation from short to intermediate axisSwitch of rotation from short to intermediate axisat high spin in at high spin in 138138Nd Nd

Short axis Short axis

Intermediate axis Intermediate axis

Short axis Short axis

Intermediate axis Intermediate axis

Band L7 of Band L7 of 138138Nd – transverse wobblingNd – transverse wobbling

C. Petrache et al., PR C86, 044321 (2012)C. Petrache et al., PR C86, 044321 (2012)

138138NdNd

wobblingwobbling

chiralchiral

M. MatsuzakiM. Matsuzaki

Nucleus Number of triaxial bands

Quadrupole bands Dipole bands

138Nd 35 27 8139Nd 8 3 5140Nd 23 12 11141Nd 7 4 3

26

The existence of stable triaxial shape at highThe existence of stable triaxial shape at highspins in Lanthanides with N < 82 is supported byspins in Lanthanides with N < 82 is supported by

more than 70 bands more than 70 bands

C. Petrache, C. Petrache, Phys. Scr. (2015)Phys. Scr. (2015)

6059

5857

56

55

50 82

66

50

64 66 68

Nd Nuclei 133Nd-136Nd

138Nd-141Nd

Intermediate axis Intermediate axis

Short axis Short axis

Conclusions, perspectives

Many questions wait an answer : - transverse wobbling in other nuclei with A=130-140- transverse wobbling in other mass regions- transverse wobbling in excited configurations- precise measurement of transition probabilities- precise measurement of mixing ratios- comprehensive interpretation of the behaior ofsequences of nuclei, like e.g. the Nd chain