Presentation is loading. Please wait.

Presentation is loading. Please wait.

Octupole correlation between the multiple chiral doublet bands in 78Br

Similar presentations


Presentation on theme: "Octupole correlation between the multiple chiral doublet bands in 78Br"— Presentation transcript:

1 Octupole correlation between the multiple chiral doublet bands in 78Br
It is a great honor for me to be allowed to speak about “octupole correlation between the multiple chiral doublet bands in bromine-78.” My name is shouyu wang. I come from Shandong university at weihai. Speaker: S. Y. Wang (王守宇) Shandong University, Weihai,China

2 Map of World Sweden China This is Sweden, that is China.

3 Map of China Weihai City
This is Map of China. I come from the Weihai city. Other people come from the Beijing city.

4 Shandong University at Weihai
Weihai is one of the most comfortable cities in China. Welcome everyone to Shandong University at Weihai Shandong University at Weihai in the Weihai city, which is one of the most comfortable cities in China. welcome to Shandong University at Weihai China-South Africa Joint Symposium on Nuclear Physics with New Generations Radioactive Ion Beams

5 Result and Discussions
Contents 1 Introduction 2 Experimental Details I’d like to give my talk in five parts. First is the introduction, second is the experimental details, third is the result and discussion, and then, the conclusion. Finally, the acknowledgement. 3 Result and Discussions 4 Conclusion 5 Acknowledgement

6 Result and Discussions
Contents 1 Introduction 2 Experimental Details First is the introduction 3 Result and Discussions 4 Conclusion 5 Acknowledgements

7 Chirality exists commonly in nature
Left- Right- Chiral symmetry is a well-known phenomenon in chemistry, biology and particle physics. Chiral symmetry is a well-known phenomenon in chemistry, biology and particle physics.

8 Frauendorf and Meng NPA617, 131 (1997)
Introduction “chiral rotation” Left-handed Right-handed In 1997, Frauendorf and Meng pointed out that the rotation of triaxial nuclei may attain a chiral character. The angular momentum of the valence proton, valence neutron, and the rotation core in the triaxial nuclei may form either a left- or right- system. In 1997, Frauendorf and Meng pointed out that the rotation of triaxial nuclei may attain a chiral character. The angular momentum of the valence proton, valence neutron, and the rotation core in the triaxial nuclei may form either a left- or right- system. Frauendorf and Meng NPA617, 131 (1997)

9 chiral symmetry breaking
Introduction Intrinsic frame Frauendorf and Meng NPA617, 131(1997) chiral symmetry breaking When the chiral symmetry is broken in the body-fixed frame, the restoration of the symmetry in the lab frame results in two nearly degenerate ΔI=one bands, namely chiral doublet bands. When the chiral symmetry is broken in the body-fixed frame, the restoration of the symmetry in the lab frame results in two nearly degenerate ΔI=1 bands, namely chiral doublet bands. Lab. frame: restoration of symmetry breaking Expected exp. signal: Two near degenerate DI =1 bands, called chiral doublet bands

10 observation of chiral bands
Since the chirality in nuclear physics was suggested, lots of experimental studies have been devoted to search for nuclear chirality. In 2001, chiral doublet bands were observed in the N = 75 isotones in the A~130 mass region. Since the chirality in nuclear physics was suggested, lots of experimental works have been devoted to search for nuclear chirality. In 2001, chiral doublet bands were observed in the N = 75 isotones['aɪsəʊtəʊn]in the A=130 mass region.

11 Island of chiral rotation
Later, an island ['aɪlənd] of chiral rotation was found in the 130 mass region. Later, an island of chiral rotation was found in the 130 mass region.

12 The observation of “chiral island”
So far, candidates for chiral doublet bands have been observed experimentally in about 39 cases of odd-odd, odd-A and even-even nuclei, including the 80, 100, 130, 190 mass regions. Most studies on nuclear chirality have focused on the 100 and 130 mass regions at first. However, there is no reason to consider the nuclei in 100 and 130 mass regions as unique in terms of the nuclear chirality. So far, candidates for chiral doublet bands have been observed experimentally in about 39 cases of odd-odd, odd-A and even-even nuclei, including the 80, 100, 130, 190 mass regions. Most studies on nuclear chirality have focused on the 100 and 130 mass regions at first. However, there is no reason to consider the nuclei in 100 and 130 mass regions as unique in terms of the nuclear chirality. A~130 mass region: Starosta01 etc. A~100 mass region: Vaman04 etc.

13 The newly “chiral island”
Thus, it is necessary to search for more candidates in other mass regions to show that the chiral symmetry is of a general nature. Recently, chiral doublet bands were also reported in the 190 and 80 mass regions. A~190 mass region: Lawrie08; Masiteng13 Thus, it is necessary to search for more candidates in other mass regions to show that the chiral symmetry is of a general['dʒen(ə)r(ə)l] nature. Recently, chiral doublet bands were also reported in the 190 and 80 mass regions. A~130 mass region: Starosta01 etc. A~100 mass region: Vaman04 etc. A~80 mass region:80Br, Wang11

14 multiple chiral bands (MχD)
In 2006, based on the triaxial RMF theory, Meng et al., suggested that besides one pair of chiral doublet bands, multiple chiral doublet bands (MχD) could exist in one single nucleus. The experimental evidences for multiple chiral doublet bands were reported in 133Ce, 103Rh, and possibly in 107Ag. In 2006, based on the triaxial RMF theory['θɪərɪ], Meng etc[ɪt'setərə, et-] suggested that besides one pair of chiral doublet bands, multiple chiral bands could exist in one single nucleus. The experimental evidences['evɪd(ə)ns] for multiple chiral bands have been already reported in some works.

15 Chirality in 80 mass region
Recently, our work on 80Br reported a pair of bands based on the g9/2g9/2 configuration, which provided the first evidence for chirality in the A~80 mass region. Recent work on 80Br reported a pair of bands based on the g9/2g9/2 configuration, which provided[prə'vaɪdɪd] the first evidence for chirality in the 80 mass region.

16 Chirality in 80 mass region
For 80 mass region, total Routhian surfaces (TRS) calculations suggest that 78Br has a remarkable triaxial shape with γ=21.3°and β=0.32 for the rotational band based on the g9/2g9/2 configuration. The deformation parameters[pə'ræmətɚ] together with the particle-hole configuration are suitable['suːtəb(ə)l] for the construction of chiral doublet bands. For this mass region, total Routhian surfaces (TRS) calculations suggest that 78Br has a remarkable triaxial shape with γ=21.3°and β2=0.32 for the rotational band based on the g9/2g9/2−1 configuration. The deformation parameters together with the particle-hole configuration are suitable for the construction of chiral doublet bands. Landulzfo 96

17 Introduction Hence, it is interesting to populate high-spin states of 78Br and to search for chiral doublet bands. It is also important to verify['verɪfaɪ] whether chirality exists in more than one odd-odd nuclei in the 80 mass region in order to provide systemic[sɪ'stɛmɪk] survey on the chiral interpretation[ɪntɜːprɪ'teɪʃ(ə)n]. Thus, it is interesting to populate high-spin states of 78Br and to search for chiral doublet bands. It is also important to verify whether chirality exists in more than one odd-odd nuclei in the A~80 mass region in order to provide systemic survey on the chiral interpretation.

18 Introduction It is also important to present new data on high-spin states of 78Br and to search for the possible multiple chiral doublet bands in the A ~80 mass region. It is also important to present new data on high-spin states of 78Br and to search for the possible multiple chiral doublet bands in the A ~80 mass region.

19 Introduction For the odd-odd nucleus 78Br with Z = 35 and N = 43, both proton and neutron Fermi surfaces lie near the g9/2, f5/2 and p3/2 orbits. Z = N = 43 For the odd-odd nucleus 78Br with Z = 35 and N = 43, both proton and neutron Fermi surfaces lie near the g9/2, f5/2 and p3/2 orbits.

20 Introduction The g9/2 and p3/2 orbits have opposite parity and Δj = Δl = 3 ħ, the interaction between these orbits will lead to the octupole correlation effect. Therefore, octupole correlation effect is also expected in 78Br, which would provide an unique chance to study the octupole correlation effect in the chiral nucleus. Based on the above considerations, experiments were performed to study high-spin states of the odd-odd nucleus 78Br. Among those orbits, The g9/2 and p3/2 orbits have opposite parity and Δj = Δl = 3 ħ, the interaction between these orbits will lead to the octupole correlation effect. Therefore, octupole correlation effect is also expected in 78Br, which would provide an unique chance to study the octupole correlation effect in the chiral nuclei. Based on the above considerations, experiments were performed to study high-spin states of the odd-odd nucleus 78Br. Butler96

21 Result and Discussions
Contents 1 Introduction 2 Experimental Details OK, now let’s focus on the experimental details. 3 Result and Discussions 4 Conclusion 5 Acknowledgements

22 Experimental Details Our experiment was carried out at the iThemba LABS in South Africa. our experiment was carried out at the iThemba LABS in South Africa.

23 Experimental Details The 70Zn (12C, 1p3n) reaction is used to populate the high-spin states of 78Br at beam energies of 60&65 MeV. This reaction is used to populate the high spin states of 78Br. Here we give the cross sections['sɛkʃən] calculated with the PACE2 program. In this figure, the black line stands for the cross section of 78Br. Based on the calculated result, beam energies of 65 and 60 MeV are used. Cross sections have been calculated with the PACE2 program.

24 Experimental Details The target is the thickness of 0.85mg/cm2. The Zn target is the self-supported metallic foil with a thickness of mg/cm2.

25 Experimental Details Here is the picture of the detector array used in the experiment. The γ-rays were recorded by the detector array AFRODITE, which consists of 8 Compton Suppressed Clover detectors. Four clovers are positioned at 135◦ with respect to the beam direction, while other four are placed at 90◦. Thus, we may extract the ADO ratios of gamma-rays to obtain information on the multipolarities. The γ-rays were recorded by the detector array AFRODITE, which consists of 8 Compton Suppressed Clover detectors. Four clovers are placed at 135°with respect to the beam direction, while other four are placed at 90°. Thus, we may extract the ADO ratios of gamma-rays to obtain information on the multipolarities.

26 Experimental Details The particle detectors array DIAMANT was also used to select reaction channels. A total of 1500 million γ-γ coincidence events were recorded in the experiment. 160 million p-γ-γ coincidence events are picked out by the DIAMANT array. The particle detectors array DIAMANT was also used to select reaction channels. A total of 1500 million γ-γ coincidence events were recorded in the experiment. 160 million p-γ-γ coincidence events are picked out by the DIAMANT array.

27 Result and Discussions
Contents 1 Introduction 2 Experiments Result and Discussions 3 Result and Discussions 4 Conclusion 5 Acknowledgements

28 Demuynck70, Christiansen72, Pleiter73, Bermudez80
The previous studies Prior to the present work, the ground state of 78Br had been assigned I = 1+ with the p3/2p1/2 configuration. Three isomeric states (2− at 32.3 keV, 4+ at keV, and 5(+) at keV) had been reported in the previous studies. The measured g-factors indicated that the 2− and 4+ isomeric states came from the p3/2g9/2 and g9/2g9/2 configurations, respectively. Prior to the present work, the ground state of 78Br had been assigned I = 1+ with the p3/2p1/2 configuration. Three isomers had been reported in the previous studies, They are 2 minus, 4plus, and 5plus , we have list their energies and life times in this table. The measured g-factors indicated that the 2− and 4+ isomeric states came from the p3/2g9/2 and g9/2g9/2 configurations, respectively. Isomer T1/2 configuration 1+ 6.5 min πp3/2υp1/2 2- 14.2 ns πp3/2υg9/2 4+ 119.2 μs πg9/2υg9/2 5(+) 84 ns unknown Demuynck70, Christiansen72, Pleiter73, Bermudez80

29 The previous studies High-spin states of 78Br have also been studied by in-beam gamma measurements. Two rotational bands were also reported in 78Br. The positive-parity band has been assigned the πg9/2νg9/2 configuration, while no configuration assignment for the negative-parity band was given in the previous works. High-spin states of 78Br have also been studied through in-beam gamma measurements. Two rotational bands were also reported in 78Br. The positive-parity band has been assigned the πg9/2νg9/2 configuration, while no configuration assignment for the negative-parity band was given. Behar82, Landulfo96

30 The present level scheme
Level scheme for 78Br obtained in this work. New observed transitions are shown by red lines. Level scheme for 78Br obtained in this work. New observed transitions are shown by red lines.

31 The present level scheme
A total of 46 new transitions and 25 new levels have been added into the level scheme. Five rotational bands are observed in the present work and labeled as 1-5 for the convenience of discussions. A total of 46 new transitions and 25 new levels have been added into the level scheme. Five rotational bands are observed in the present work and labeled as 1-5 for the convenience[kən'viːnɪəns] of discussions.

32 The present level scheme
The present work confirms most of the previously known level structures, and extends bands 1 and 3 up to 20+ and 19−, respectively. Furthermore, 15 new interband transitions and three new rotational bands labeled as 2, 4, and 5 have been identified and added in the present level scheme. The present work confirms most of the previously known level structures, and extends bands 1 and 3 up to 20+ and 19−, respectively. In addition, 15 new interband transitions and three new rotational bands labeled as 2, 4, and 5 have been identified and added in the present level scheme.

33 The present level scheme
preliminary This figure shows the sample spectra supporting the present level scheme. Most of new gamma-rays can be clearly seen in this figure. This figure shows the sample spectra supporting the present level scheme. Most of new gamma-rays can be clearly seen in this figure.

34 Results and Discussion
One of the interesting aspects of the present work is the observation of two pairs of nearly degenerate bands. One of the interesting aspects of the present work is the observation of two pairs of nearly degenerate bands, bands 1,2 and bands 3,4.

35 Results and Discussion
One of the interesting aspects of the present work is the observation of two pairs of nearly degenerate bands. One of the interesting aspects of the present work is the observation of two pairs of nearly degenerate bands, bands 1,2 and bands 3,4. Bands 1 and 2 Bands 3 and 4

36 Bands 1 and 2 In order to discuss the features of the two pairs of nearly degenerate bands, the experimental energy E(I), energy staggering parameter S(I), and B(M1)/B(E2) ratios are extracted and shown in this figure. bands 1 and 2 maintain a small energy difference. They have similar S(I) and B(M1)/B(E2) values within the observed spin region. The B(M1)/B(E2) values show obvious odd-even stagger. The two positive parity bands in 78Br show similar experimental features with those in 80Br, which have been suggested as the first candidate of chiral bands in the 80 mass region. In order to discuss the features of the two pairs of nearly degenerate bands, the experimental energy spectra E(I), energy staggering parameter S(I), and electromagnetic transition ratios B(M1)/B(E2) are extracted. As shown in this figure, bands 1 and 2 maintain a small energy difference. They have similar S(I) and B(M1)/B(E2) values within the observed spin region. The B(M1)/B(E2) values show obvious odd-even stagger. The two positive parity bands in 78Br show similar experimental features with those in 80Br, which have been suggested as the first candidate of chiral bands in the 80 mass region. Taking the experimental results into account, bands 1 and 2 in 78Br may be considered as candidates for chiral doublet bands. Taking the experimental results into account, bands 1 and 2 in 78Br may be considered as a candidate for chiral doublet bands.

37 Bands 3 and 4 For band 3, no configuration assignment was given in the previous studies. Bands 3 and 4 show similar experimental features. The presence of strong linking transitions points to both bands having the same configurations. Thus, we suggest bands 3 and 4 as another candidate for chiral doublet bands in 78Br. For band 3, no configuration assignment was given in the previous studies. Bands 3 and 4 show similar experimental features. The presence of strong interconnecting transitions points to both bands having the same configurations. Thus, we suggest bands 3 and 4 as another candidate for chiral doublet bands in 78Br.

38 Configurations of bands 3 and 4?
Among the single-particle orbits which lie close to the Fermi level, the p3/2 or f5/2 and g9/2 orbits occupied by the unpaired proton or neutron will lead to the negative parity. Z = N = 43 For the odd-odd nucleus 78Br with Z = 35 and N = 43, both proton and neutron Fermi surfaces lie near the g9/2, f5/2 and p3/2 orbits. Among the single-particle orbits which lie close to the Fermi level, the (p3/2; f5/2) and g9/2 orbits occupied by the unpaired proton or neutron will lead to the negative parity.

39 Configurations of bands 3 and 4?
g9/2g9/2 Isomer T1/2 configuration 1+ 6.5 min πp3/2υp1/2 2- 14.2 ns πp3/2υg9/2 4+ 119.2 μs πg9/2υg9/2 5(+) 84 ns unknown f5/2g9/2 We tentatively assigned the πf5/2νg9/2 configuration for bands 3 and 4, because the πp3/2νg9/2 configuration has been assigned to the 2− isomer of 78Br. We tentatively assigned the πf5/2νg9/2 configuration for bands 3 and 4, as the πp3/2νg9/2 configuration has been assigned to the 2− isomer of 78Br

40 theoretical calculations
In order to discuss the features of the two pairs of nearly degenerate bands, theoretical calculations based on a combination of the multidimensional constrained relativistic mean-field (MDC-RMF) approach and the triaxial particle-rotor model (TPRM) were performed. In order to discuss the features of the two pairs of nearly degenerate bands, theoretical calculations based on a combination of the MDC-RMF theory and the triaxial particle-rotor model (TPRM) were performed.

41 MDC-RMF Calculations Based on the multidimensional constrained relativistic mean-field (MDC-RMF) calculations, the deformation parameters are (β2,γ) = (0.32,15.1) and (0.23, 26.3) for the two pairs of bands, respectively. Based on the multidimensional constrained relativistic mean-field (MDC-RMF) calculations, the deformation parameters are (β,γ) = (0.32,15.1) and (0.23, 26.3) for the two pairs of bands, respectively. For the isomers and the bandheads of bands 1 and 3, the calculated excitation energies relative to the ground state are reasonably coincident with the corresponding experimental data. The deformation parameters of the calculated states in 78Br are listed in this table. For the isomers and the bandheads of bands 1 and 3, the calculated energies relative to the ground state are coincident with the corresponding experimental data. The deformation parameters of the calculated states in 78Br are listed in this table. Lu12, Zhao12, Lu14

42 Triaxial particle-rotor model (TPRM) calculation
These deformation parameters from the (MDC-RMF) calculations are adopted as inputs in the TPRM calculations. The other input parameters are obtained as follows: Then, these deformation parameters are adopted as inputs in the TPRM calculations. The other input parameters are obtained as follows Wang07, Zhang07, Wang08

43 Triaxial particle-rotor model (TPRM) calculation
The calculated results for bands 1, 2 and bands 3, 4 in 78Br were shown in this Figure, together with the corresponding experimental results. The theoretical results show a good agreement with the experimental data. For the two pairs of bands, the magnitude, stagger, and trend of the E(I), S(I) and the B(M1)/B(E2) ratios are reproduced quite well. The good agreement between the calculated values and the available experimental data supports the present configuration assignments. The calculated results for bands 1, 2 and bands 3, 4 in 78Br were shown in this Figure, together with the corresponding experimental results. The theoretical results show a good agreement with the experimental data. For the two pairs of bands, the magnitude, stagger, and trend of the E(I), S(I) and the B(M1)/B(E2) ratios are reproduced quite well. The good agreement between the calculated values and the available experimental data supports the present configuration assignments.

44 The effective angles To obtain a clear chiral pictures of 78Br, the effective angles between the angular momentum of the valence proton, valence neutron, and rotation core for the two pairs of doublet bands in the body-fixed frame are calculated by the TPRM as follows in Ref{Wang08} and shown in this figure. To obtain a clear chiral pictures of 78Br, the effective angles between the angular momentum vectors of the valence proton, valence neutron, and rotation core for the two pairs of doublet bands in the body-fixed frame are calculated by the TPRM as follows in Ref{Wang08} and shown in this figure.

45 The effective angles For bands 1 and 2, the effective angles are larger than 45◦ in the observed spin region. For bands 3 and 4, the effective angles are larger than 45◦ in the low spin region, while the effective angle between the rotation core and the valence neutron are close to 45◦ in the high spin region. for bands 1 and 2, the effective angles are larger than 45◦ in the observed spin region. For bands 3 and 4, the effective angles are larger than 45◦ in the low spin region, while the effective angle between the rotation core and the valence neutron are smaller than 45◦ in the high spin region. It may be attributed to the neutron Fermi surface lies in the middle of the g9/2 shell. The calculated results suggest clear nonplanar rotations for bands 1,2 and bands 3,4 in 78Br. Based on the above analysis, bands 1,2 and bands 3,4 in 78Br can be interpreted as two pairs of chiral doublet bands, thereby forming a multiple chiral doublet. The calculated results suggest the clear nonplanar(aplanar) rotations for bands 1,2 and bands 3,4 in 78Br. Based on the above analysis, bands 1,2 and bands 3,4 in 78Br can be interpreted as two pairs of chiral doublet bands, thereby forming a multiple chiral doublet bands (MχD).

46 Results and Discussion
In short, the observed two positive-parity bands and two negative-parity bands are proposed to be multiple chiral doublet bands with the πg9/2νg9/2 and πf5/2νg9/2 configurations, respectively. In short, the observed two positive-parity bands and two negative-parity bands are proposed to be multiple chiral doublet bands with the πg9/2νg9/2 and πf5/2νg9/2 configurations, respectively.

47 Results and Discussion
Another interesting aspect of the present work is the observation of the five new linking transitions between the opposite-parity bands 1 and 3. Another interesting aspect of the present work is the observation of the five new linking transitions between the opposite-parity bands 1 and 3.

48 Results and Discussion
The observation of the E1 transitions between bands 1 and 3 indicates that octupole correlations exist in 78Br. The observation of the E1 transitions between bands 1 and 3 indicates that octupole correlations exist in 78Br.

49 Results and Discussion
g9/2g9/2 f5/2g9/2 The observation of octupole correlation effect indicates there is a p3/2 component mixed with the f5/2 component as the two orbits are very close to each other in energy. The interaction between the g9/2 and the p3/2 components in the configurations will give rise to the octupole correlations effect in 78Br. The observation of octupole correlation effect implies there is a p3/2 component mixed with the f5/2 component as the two obits are very close to each other in energy. The interaction between the g9/2 and the p3/2 components in the configurations will give rise to the octupole correlations effect in 78Br.

50 Results and Discussion
The MDC-RMF is also used to calculate the octupole deformation of 78Br. The contour separation is 0.2 MeV. The calculated potential energy surface for the ground state of 78Br in the β20-β30 plane is given in this figure. In the present work, the MDC-RMF calculations are also used to investigate the octupole deformation of 78Br. The calculated potential energy surface for the ground state of 78Br in the β20-β30 plane is given in this figure. One can see from the figure that The potential energy surface is very soft with respect to the β30 degree of freedom, which implies the possibility of octupole correlations. The observation of octupole correlation effect in 78Br indicates that chiral geometry can exist in octupole soft nuclei. The potential energy surface is very soft with respect to the β30 degree of freedom, which implies the possibility of octupole correlations. The observation of octupole correlation effect in 78Br indicates that chiral geometry can exist in octupole soft nuclei.

51 Results and Discussion
To study the octupole correlation effect, the experimental B(E1)/B(E2) ratios as a function of spin are extracted and shown in this figure. The experimental B(E1)/B(E2) ratios as a function of spin in 78Br. To study the octupole correlation effect, the experimental B(E1)/B(E2) ratios as a function of spin are extracted and shown in this figure. We can see clearly from the figure that the experimental B(E1)/B(E2) ratios increase with the spin increases, which indicates that octupole correlation effect becomes more remarkable as the spin increases. We can see clearly from the figure that the experimental B(E1)/B(E2) ratios increase with the spin increases, which indicates that octupole correlation effect becomes more remarkable as the spin increases.

52 Results and Discussion
We note that the octupole correlation effect becomes stronger as the spin increases, however, the absence of the side bands at high spin region for two pairs of chiral bands means the chiral effect becomes weaker or even vanishes. A competition between octupole correlation effect and chirality is clearly shown in 78Br. We note that the octupole correlation effect becomes stronger as the spin increases. However, the absence of the side bands at high spin region for two pairs of chiral bands means the chiral effect becomes weaker or even vanishes. A competition between octupole correlation effect and chirality is clearly shown in 78Br.

53 Result and Discussions
Contents 1 Introduction 2 Experiments now let’s come to the conclusion. 3 Result and Discussions 4 Conclusion 5 Acknowledgements

54 Conclusion High-spin states of 78Br were populated using the 70Zn(12C, 1p3n) reaction at the iThemba LABS in South Africa. The previously known level scheme of 78Br has been extended. The observed two positive-parity bands and two negative-parity bands are proposed to be multiple chiral doublet bands. The octupole correlation effect is also observed in 78Br. It is the first identification of octupole correlation between multiple chiral doublet bands in atomic nuclei. The observation indicates that chiral geometry can exist in octupole soft nuclei. A competition between octupole correlation effect and chirality is clearly shown in 78Br. High-spin states of 78Br were populated using this reaction at the iThemba LABS in South Africa. The previously known level scheme of 78Br has been extended. The observed two positive-parity bands and two negative-parity bands are proposed to be multiple chiral doublet bands. The octupole correlation effect is also observed in 78Br. It is the first identification of octupole correlation between multiple chiral doublet bands in atomic nuclei. The observation indicates that chiral geometry can exist in octupole soft nuclei. A competition between octupole correlation effect and chirality is clearly shown in 78Br.

55 Acknowledgement iThemba Labs: R. Bark, E. Lawrie, T.D. Bucher, A. Kamblawe, E. Khaleel, N. Khumalo, E. A. Lawrie, J. J. Lawrie, P. Jones, S. M. Mullins, S. Murray, M. Wiedeking, S. N. T. Majola, J. Ndayishimye, D. Negi, S. P. Noncolela, O. Shirinda, P. Sithole, M. A. Stankiewicz, T. Dinoko, J. Easton Stellenbosch University: S. M. Wyngaardt, P. Papka, University of the Western Cape: J. F. Sharpey-Schafer, J. N. Orce University of Zululand: S. S. Ntshangase ATOMKI, Hungury: B.M. Nyakó, K. Juhász Peking Univ.: J. Meng, S. Q. Zhang, H. Hui, X. Q. Li, C. Xu, Tsinghua Univ: Z. G. Xiao, H. J. Li Shandong Univ: B. Qi, C. Liu, I’ve listed my co-workers on the slice. That is all my talk. Thank you very much! Thank you for your attention and suffer from my spoken English. Supported by NSFC & NRF & China-SA collaboration!


Download ppt "Octupole correlation between the multiple chiral doublet bands in 78Br"

Similar presentations


Ads by Google