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

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

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

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 Physics 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.

single-particle levels in the nuclear shell model

Limits of long-lived SHN ?

n-rich exotic nuclei - transuranium n-rich exotic nuclei - transuranium

n-rich exotic nuclei around Z ～ 70

RIKEN-Garis: Thickness of target 0.48mg/cm 2 ， Research period 170 days Z=113 in RIKEN preliminary Mt 266 Bh CN MeV (PSD) 344 μs mm MeV (PSD+SSD) ms mm MeV (PSD+SSD) ms mm 9.08 MeV (PSD) s mm MeV TOF ns mm 23-July :55 (JST)     1 st chain 262 Db MeV(PSD) 40.9 s mm Mt 266 Bh CN MeV (PSD) 4.93 ms mm =11.31 MeV (PSD+SSD) 34.3 ms mm 2.32 MeV (escape) 1.63 s mm 9.77 MeV (PSD) 1.31 s mm MeV TOF ns mm 2-April :18 (JST) 70 Zn Bi → n     262 Db MeV(PSD) s mm 2 nd chain s.f.  = 78 fb J. Phys. Soc. Jpn 73(2004)2593 From K. Morita’s talk in 2005

Z=113 in Dubna

_ 0.53 MeV 0.85 ms13.66 MeV 17.5 mm  March 19, :43 SF MeV 0.15 s 16.8 mm 202 (151+51) MeV 2.7 ms 16.9 mm MeV 0.1 ms 17.0 mm 1    2 3 Dubna － DGFRS: 249 Cf+ 48 Ca  n Z=118

SHE in Lanzhou Z=110

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

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 ？

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

Z=120 A master equation for fusion dynamics

Z=120 A combined DNS and advanced statistical models

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

Z=119, 120 A diffusion model

A Langevin equation for fusion dynamics Z=120

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

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, (R) (2015)

Recent Exp by W. Loveland

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

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

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

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

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

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

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

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

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

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

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

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

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

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)

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

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

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

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

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)

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

Fusion probability: Survival probability:

The orientation effects for 48 Ca+ 238 U

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

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

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)  (120,184) exp. ISOLDE, CERN, 2016

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

TKEL~  Z 2 TKEL increasing ，  Z 2 increasing

The master equation

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

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

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) Xe Pb, 514 MeV U Cm, 800 MeV

Yb ＋ 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~ Eu, N=102, ~  b Eu, N=103, ~0.5  b Eu, N=104, ~10 pb Eu, N=105, ~ pb For projectile like 70+z Yb 106+N

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)  (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

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

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