Nuclear Physics Sakurai Hiroyoshi Fundamental interactions Elementary particles

Nuclear Physics Sakura-i Hiro-yoshi 櫻 井 博 儀

Fundamental interactions Elementary particles Composite particles

Nuclear Physics is not Particle Physics, not Condensed Matter Physics Interaction? Effective interaction ? Correlations ? Isospin, Density, temperature dependences ? Surface boundary, non-linear, finite system

Q. 1 Life time of neutron？ Q. 2 Age of universe is 13. 7 B Years after Big. Bang. At present, there are neutrons in materials. Why? Q. 3 Spin-parity for ground state of deuteron？ Q. 4 Limits of existence of nuclei？ Q. 5 Magic numbers of nuclei？ Q. 6 Size of nuclei？ Q. 7 Collective motions of nuclei？ Q. 8 How and where elements around us have been created ?

Exploration of the Limit of Existence stable nuclei unstable nuclei observed so far drip-lines (limit of existence)（theoretical predictions) magic numbers in 1995 ~300 nuclei ~2700 nuclei ~6000 nuclei proton drip-line proton-rich nuclei proton number (Z) neutron drip-line neutron-rich nuclei in 1985 neutron number (N)

Nuclear Collective Motion closed shell at magic number spherical nuclei |b|~0 open shell surface vibration Quadrupole deformation parameter b deformed nuclei |b| large degree of collectivity E(4+)/E(2+) ~ 1. 8 ~ 2. 2 ~ 3. 3

Solar Abundance of Elements Big Bang Nucleosynthesis in stellars (fusion） Nucleosynthesis in r-process path 金 T. Motobayashi

r-process path in supernova explosion Photo-disintegration of ion nuclei Electron capture reaction Proton number 陽子数 Emission of big amount of neutron and neutrino Au Beta decay Z, N -> Z+1, N-1 r-process Neutron capture Beta decay Neutron number 中性子数 Fe to U

Exploration of the Limit of Existence stable nuclei unstable nuclei observed so far drip-lines (limit of existence)（theoretical predictions) magic numbers in 1995 ~300 nuclei ~2700 nuclei ~6000 nuclei proton drip-line proton-rich nuclei proton number (Z) neutron drip-line neutron-rich nuclei in 1985 neutron number (N)

RIKEN RI Beam Factory (RIBF) Experiment facility Old facility To be funded Accelerator RIPS ~100 Me. V/nucleon GARIS SHE (eg. Z=113) ~5 Me. V/nucleon RILAC SCRIT AVF f. RC Zero. Degree RRC SAMURAI SRC SLOWRI RI-ring IRC CRIB (CNS) New facility Big. RIPS SHARAQ 350 -400 Me. V/nucleon Intense (80 k. W max. ) H. I. beams (up to U) of 345 AMe. V at SRC Fast RI beams by projectile fragmentation and U-fission at Big. RIPS Operation since 2007

Exploration of the Limit of Existence Great expansion of nuclear world by RIBF Intensity > 1 particle/day 4000 species of isotopes can be created at RIBF 1000 new isotopes + 3000 known isotopes protons New Element 278 113 04 July 23 18: 55 57 fb Projectile Fragmentation In-flight U fission & P. F. 78 Ni ~0. 1 particles/sec. (goal) (2007) 10 particles/sec. by by 10 pn. A 1 pm. A 350 Me. V/u U-beam neutrons

RI beam production via in-flight method RI production RI beam separator （to collect and separate RI with analyzing magnets） Heavy ion accelerator target （to accelerate nuclei） （to make reactions Be, C, etc） Advantage of fission via U beam RI beam Probability Fission reaction via 238 U beam N=50 Yield rate of 78 Ni via fission is about 1､ 000 times higher than via fragmentation. 10, 000: 1 Fragmentation reaction via 86 Kr beam 78 Ni Proton number

SRC World’s First and Strongest K 2600 Me. V Superconducting Ring Cyclotron 400 Me. V/u Light-ion beam 345 Me. V/u Uranium beam Big. RIPS World’s Largest Acceptance 9 Tm Superconducting RI beam Separator ~250 -300 Me. V/nucleon RIB K 980 -Me. V Intermediate stage Ring Cyclotron (IRC)

Three Challenges of RIBF 1 To Establish New Framework of Nuclear Physics 2 To Elucidate the Origin of Elements 3 To Explore New Applications with fast RI Beams 2

New frameworks for the new region of nuclear chart Nuclear Structure: Shell evolution Nuclear Matter: New forms Stable Nuclei Neutron-rich Nuclei ? neutron-skin nuclei ? ? neutron-halo nuclei N=16 N=6 11 Be, 11 Li, 19 C. . . To write up new text book： Exotic phenomena, Systematics, etc. Isospin-, density-dependences of effective interactions, nucleon-corrections Microscopic system (nuclei) to Macroscopic system (neutron stars)

Liberation from Stable Region and Exotic Nuclei Shell Evolution : magicity loss and new magicity Spherical Deformed Shape ? Shell gap？ Single particle level？ Cluster formation? Role of 3 NF ? Magicity loss ？ 50、82、126、184 E(2+) Dynamics of new “material” : Neutron-skin（halo） Density distribution neutron skin Neutron+ proton陽子・中性子 neutron 一様物質 matter neutrons r Skin thickness？Density distribution？ Role of skin in reactions？ Pairing in skin？ di-neutrons? Exotic modes of skin？ RIBF provides data for nuclei far from the stability line Challenges in establishing new frame work of nuclear physics

Challenge for r-process path and explosion in supernovae Synthesis up to U （r-process） unknown neutron-rich nuclei theoretical predictions only Necessary of experimental investigation for nuclear properties of heavy and neutron-rich nuclei Mass, life-time, decay mode Mass number Explosion mechanism of supernova No explosion in theoretical works Outer clast of neutron star Necessary of experimental study for Equation-of-State for nuclear matter 1987 A 5

Challenge to investigate EOS of neutron matter from nuclei to neutron stars B. A. Brown, PRL 85 (2000) 5296 E/A [Me. V] pure neutron matter Normal density 3 NF T=3/2 channels? density dependence? Elastic d+p for T=1/2 Nuclear structure in very neutron-rich nuclei for T=3/2? Heavy-ion Collisions to achieve r~2 -3 r 0 ? 3 P r (fm-3) 1 S correlation BCS-BEC crossover in dilute system (r ~ 0. 1 r 0) ? correlation pairing gap? Density depencence? 2 ? ? Role of di-neutron in skin? : collectivity, transfer reactions

The First RI Beam Experiment (1974) Many pieces of interesting work done at the Bevalac in biology using animals and plants Measurement of blood circulation using RI beams Usually expected Due to blood circulation inside the brain T 1/2 = 2 min. 15 O ® e+ + 15 N e+ + e- ® 2 15 O Courtesy of C. A. Tobias Beam Copy-right S. Nagamiya

Development of Nuclear Physics and Applications 1900 20 40 Discovery of Nuclei and Radioactive Isotope Radio-therapy, -sterilization … Dating Nuclear Force and Electromagnetic moments Spectroscopy and nuclear matter 14 C MRI Mossbauer Tracer 60 Meson Production 80 Giant resonances and high spin states PET Radioactive Isotope Beams Material Science 2000 m. SR New Cancer Therapy RI production for all of elements high energy Nuclear Transformation ？？？ 9

New Devices of RIBF To maximize the potentials of intense RI beams available at RIBF for several 100 – 1000 species Rare RI ring Zero. Degree mass half-life excited states deformation charge radii to be funded 2008 matter radii charge distribution SLOWRI IRC-to-RIPS BT matter distribution EM moments single particle states astrophysical reactions giant resonances to be funded exotic modes SAMURAI HI collisions (EOS) SCRIT SHARAQ spectrometer U Tokyo 2011 - 2009 - 2010 -

RI Beam Facilities in the world Finland JYFL Germany GSI Russia JINR China IMP CIAE France GANIL SPIRAL-I, II (2010 -) SISSI+LISE Canada TRIUMF/ISAC USA MSU/NSCL ORNL/HRIBF ANL Texas A&M Switzerland CERN/ISOLDE Italy LNS Japan RIKEN KEK-JAEA/TRIAC India VECC IUAC Red colored: In-flight method

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