1. Feng-Shou Zhang College of Nuclear Science and Technology Beijing Normal University, Beijing, China Collaborators: Long Zhu, Bao-An Bian, Hong-Yu Zhou, BNU, Beijing Zhao-Qing Feng, Gen-Min Jin, IMP, Lanzhou Production cross sections for superheavy and neutron-rich nuclei The 9th Japan- China Joint Nuclear Physics Symposium, Nov. 7-13, 2015, Osaka

2. Outline 1. Introduction 2. Theoretical models 3. Dynamical fusion barriers 4. Production cross sections of 119 and 120 5. Recent results for large mass (charge) transfer reaction and reaction induced by RNB 6. Summary

3. JCNP2015 ， Nov. 8-13 ， Osaka 1. K. Morita, SHE research at RIKEN/GARIS 2. Z.G. Gan, Alpha-decay of the n-deficient isotopes 215-217U 3. Y. Watanabe, Experimental study of multi- nucleon transfer reactions of 136Xe+198Pt for KIS project

4. 2. Maria Goeppert-Mayer and Hans Jensen For their discoveries concerning nuclear shell structure 1.Eugene Paul Wigner For contributions to fundamental symmetry principles in both nuclear and particle physics The Nobel Prize in Physics1963 http://nobelprize.org/physics/laureates/1963 Introduction By the end of 1940, Mayer and Jensen put up their model by a strong spin-orbit coupling of nuclear force, which can explains why nuclei with so-called magic numbers of protons and neutrons are particular stable.

5. single-particle levels in the nuclear shell model

6. Limits of long-lived SHN ?

7. n-rich exotic nuclei - transuranium n-rich exotic nuclei - transuranium

8. n-rich exotic nuclei around Z ～ 70

9. RIKEN-Garis: Thickness of target 0.48mg/cm 2 ， Research period 170 days Z=113 in RIKEN preliminary 278 113 274 111 270 Mt 266 Bh CN 11.68 MeV (PSD) 344 μs 30.49 mm 11.15 MeV 6.149+5.003 (PSD+SSD) 9.260 ms 30.40 mm 10.03 MeV 1.136+8.894(PSD+SSD) 7.163 ms 29.79 mm 9.08 MeV (PSD) 2.469 s 30.91 mm 36.75 MeV TOF 44.61 ns 30.33 mm 23-July-2004 18:55 (JST)     1 st chain 262 Db 204.05 MeV(PSD) 40.9 s 30.25 mm 278 113 274 111 270 Mt 266 Bh CN 11.52 MeV (PSD) 4.93 ms 30.16 mm 0.88+10.43=11.31 MeV (PSD+SSD) 34.3 ms 29.61 mm 2.32 MeV (escape) 1.63 s 29.45 mm 9.77 MeV (PSD) 1.31 s 29.65 mm 36.47 MeV TOF 45.69 ns 30.08 mm 2-April-2005 2:18 (JST) 70 Zn + 209 Bi → 278 113 + n     262 Db 192.32 MeV(PSD) 0.787 s 30.47 mm 2 nd chain s.f.  = 78 fb J. Phys. Soc. Jpn 73(2004)2593 From K. Morita’s talk in 2005

10. Z=113 in Dubna

11. 114 286 116 290 11.80 + _ 0.53 MeV 0.85 ms13.66 MeV 17.5 mm 118 294 297  March 19, 2005 07:43 SF 112 282 10.16 MeV 0.15 s 16.8 mm 202 (151+51) MeV 2.7 ms 16.9 mm 10.80 MeV 0.1 ms 17.0 mm 1    2 3 Dubna － DGFRS: 249 Cf+ 48 Ca  294 118+3n Z=118

12. SHE in Lanzhou Z=110

14. Nuclear physicists contributions a lot to produce new elements: Z=93-118

20. Nuclear physicists contribution in future to 119 and 120 ? Z=2, 8, 20, 28, 50, 82, next ？ N=2, 8, 20, 28, 50, 82, 126, next ？ Double magic nuclei: 4He, 16O, 40Ca, 56Ni, 132Sn, 208Pb, next ？

23. Recent progress for production of Z=119 and 120 Based on the DNS model

24. Z=120 A master equation for fusion dynamics

25. Z=120 A combined DNS and advanced statistical models

26. Z=119, 120 A dynamical potential energy surface—the DNSDyPES model

27. Z=119, 120 A diffusion model

28. A Langevin equation for fusion dynamics Z=120

29. The maximal production cross sections: pb L Zhu, WJ Xie, FS Zhang, Physics Review C 89 (2014) 024615 Z=119, Z=120

31. FRDM ： 50Ti+248Cf, ERC:0.186pb 54Cr+248Cm, ERC:0.062pb KTUY ： 50Ti+249Cf, ERC:6.57Pb 54Cr+248Cm, ERC:11.3Pb Z=119, Z=120 X. J. Bao, Y. Gao, J. Q. Li, H. F. Zhang * ， PHYSICAL REVIEW C 91, 011603(R) (2015)

32. Recent Exp by W. Loveland

34. Outline 1. Introduction 2. Theoretical models 3. Dynamical fusion barriers 4. Production cross sections of 119 and 120 5. Recent results for large mass (charge) transfer reaction and reaction induced by RNB 6. Summary

35. Fusion barrier ： Shell correction ： From IQMD to ImIQMD BA Bian, FS Zhang, PLB 665 (2008) 314–317 ZQ Feng, GM Jin, FS Zhang, Nuclear Physics A 802 (2008) 91–106 ZQ Feng, GM Jin, FS Zhang, Nuclear Physics A 750 (2005) 232–244 force derived from the shell correction energy ： 1. Stability: Friction 2. Surface energy: Switch function 3. Structure (Shell, pair, …) : Shell model, 2-center Shell model, Deformed 2-center shell model Several key problems

36. Deformed Two-Center Shell Model (DTCSM) Gherhhescu, Greiner, Munzenberg, PRC68 (2003)054314

37. Shell corrections for Magic numbers Moeller, Nix, Myers, Swiatecki Nucl. Data Tables 59(1995)185 E p shell (82)=-5.5 MeV, E n shell (126)=-6.8 MeV E p,n shell (50)=-5.1 MeV E p,n shell (28)=-1.24 MeV E p,n shell (20)=-3.6 MeV E p,n shell (8)=-2.2 MeV Gherhhescu, Greiner, Munzenberg, PRC68 (2003)054314

38. DTCSM for cold fusion reaction Gherhhescu, Greiner, Munzenberg, PRC68 (2003)054314

39. Static fusion barrier for 40 Ca / 48 Ca + 40 Ca/ 48 Ca ZQ Feng, GM Jin, FS Zhang, Nuclear Physics A 750 (2005) 232–244

40. ZQ Feng, GM Jin, FS Zhang, Nuclear Physics A 802 (2008) 91–106

41. Capture cross sections 48 Ca+ 208 Pb/ 238 U  224 102, 254 112 exp: Dasgupta et al., NPA734, 148(2004) Nishio et al., PRL93, 162701(2004) ZQ Feng, GM Jin, FS Zhang, Nuclear Physics A 802 (2008) 91–106

43. Outline 1. Introduction 2. Theoretical models 3. Dynamical fusion barriers 4. Production cross sections of 119 and 120 5. Recent results for large mass (charge) transfer reaction and reaction induced by RNB 6. Summary

44. Dynamic barrier distribution for 36 S + 90 Zr at 80, 85 MeV ZQ Feng, GM Jin, FS Zhang, Nuclear Physics A 802 (2008) 91–106 Dynamica Coulomb Barriers

45. 3.1 Effects of shell correction L Zhu, J Su, WJ Xie, FS Zhang, Nuclear Physics A 915 (2013) 90-105 The shell corrections for the reactions 16 O+ 208 Pb, 204 Pb

46. L Zhu, J Su, WJ Xie, FS Zhang, Nuclear Physics A 915 (2013) 90 K Washiyama, D Lacroix, Phys. Rev. C78(2008) 024610 3.2 Incident energy dependence of fusion barriers

47. 3.3 Isospin effects Symmetric isotope reaction systems A Ni+ A Ni (A=48, 54, 58,64) The fusion barrier for the neutron rich system is lower than that of the proton rich system. The height of the barrier increase with decreasing N/Z, while the opposite behavior can be seen for the radius of fusion barrier

48. For the deformed reactions, the static deformation is important which can influence the fusion barrier distribution Orientation effects for 16 O+ 154 Sm 3.4 Orientation effects of fusion barriers L Zhu, J Su, WJ Xie, FS Zhang, Nuclear Physics A 915 (2013) 90-105

49. Physics behind from ImIQMD calculations and behaviors dynamical barriers 1.It’s expensive to use microscopic models to calculate the exact evaporation residue cross section 2.The mass asymmetry η, E*, potential pocketΔ R, orientation θ, are important to the fusion probability 3. Need to use a phenomenological model

50. Outline 1. Introduction 2. Theoretical models 3. Dynamical fusion barriers 4. Production cross sections of 119 and 120 5. Recent results for large mass (charge) transfer reaction and reaction induced by RNB 6. Summary

51. The picture of synthesizing SHE: DNS model T DNS P ER CN SF neutrons Capture processDNS compounded Quasi fission Full fusion Evaporate nutreons

52. The 1st test W. Reisdorf, Z. Phys. A 300, 227 (1981)

53. The maximal production cross sections for Z=119: The maximal production cross sections for Z=120: pb Production cross sections of Z=119 and 120 L Zhu, WJ Xie, FS Zhang, Physics Review C 89 (2014) 024615

54. Orientation effects for Z=119,120 ER cross sections: capture cross sections:

55. Fusion probability: Survival probability:

56. The orientation effects for 48 Ca+ 238 U

57. Production cross sections of Z=119 and 120 L Zhu, ZQ Feng, FS Zhang, Physics Review C 90 (2014) 014612 0.23 pb (3n), 0.32 pb (4n) 0.11 pb (3n), 0.23 pb (4n)

59. Outline 1. Introduction 2. Theoretical models 3. Dynamical fusion barriers 4. Production cross sections of 119 and 120 5. Recent results for large mass (charge) transfer reaction and reaction induced by RNB 6. Summary

60. The 2nd and 3rd exp. methods 2nd: large mass (charge) transfer process in DIC 3rd: Sophie Heinz (GSI, 2014): Probing the stability of superheavy nuclei with radioactive ion beams, 95 Rb(37,58)+ 209 Bi(83,126)  304 120(120,184) exp. ISOLDE, CERN, 2016

61. DIC process Book ： Nuclear Multifragmentation ， F. S. Zhang & L. X. Ge, 1998, Science Press, Beijing

62. TKEL~  Z 2 TKEL increasing ，  Z 2 increasing

63. The master equation

64. when x approaches x’ ， one expands this eq around x’=x, up to the 2nd order of (x-x’) ， one gets Fokker-Plank eq

65. For the average value and its mean square deviation  x 2 That means the is proportional to v, and the mean square deviation  x 2 is also proportional to D

66. For target-like(Z=96) fragments, Transfer 3, 4, and 5 protons Exp. Data: Schadel et al., PRL48 (1982)852 For target-like(Z=82) fragments, Transfer 2, 4, and 6 protons Exp. Data: Kozulin et al., PRC86 (2012)044611 136 54 Xe + 208 82 Pb, 514 MeV 238 92 U + 248 96 Cm, 800 MeV

67. 176 70 Yb ＋ 238 92 U Transfer 7 protons, Eu 5 protons, Tb 3 protons, Ho 0 protons, Yb For un know n-rich nuclei A 63 Eu, A=165~168 165 63 Eu, N=102, ~  b 166 63 Eu, N=103, ~0.5  b 167 63 Eu, N=104, ~10 pb 168 63 Eu, N=105, ~ pb For projectile like 70+z Yb 106+N

68. 2nd and 3rd exp. methods 2nd: large mass (charge) transfer process in DIC 3rd: Sophie Heinz (GSI, 2014): Probing the stability of superheavy nuclei with radioactive ion beams, 95 Rb(37,58)+ 209 Bi(83,126)  304 120(120,184) exp. ISOLDE, CERN, 2016 Is it possible to use RNB from IMP, or RIKEN to produce Z=120 ??? 5. Recent results for large mass (charge) transfer reaction and reaction induced by RNB

70. Possible exp in IMP ， 176 Yb+ 238 U E c.m. = 600 MeV Possible exp in KEK, RCNP, RIKEN ?

71. 6. Summary 1.Dynamical barriers are very important for the fusion reactions, a phenomenological method, including the contributions from mass asymmetry, potential pocket, orientation, is used 2.Through the reactions 48 Ca+ 252 Es and 48 Ca+ 257 Fm, the SHN Z=119 and Z=120 could be synthesized (0.2~0.3 pb), if enough amount of 252 Es and 257 Fm can be collected to make targets 3.Some other methods, such as the large mass (charge) transfer process and reaction induced by RNB, etc, are welcome, we needed to try to synthesize neutron rich SHE Thank you for your attention