Experimental Study of Three Nucleon Experimental Study of Three Nucleon Forces via Few Nucleon SystemForces via Few Nucleon System
RIKENRIKEN
Kimiko SekiguchiKimiko Sekiguchi
Three Nucleon Force (3NF)
1957 Fujita-Miyazawa 3NF Model1957 Fujita-Miyazawa 3NF Model
Prog. Theor. Phys. 17, 360 (1957)Prog. Theor. Phys. 17, 360 (1957)
Three nucleon force (3NF) has been predictedas a concept of the meson theory.
1934 Yukawa’s meson theory(2NF)1934 Yukawa’s meson theory(2NF)
1950’s N scattering experiment (1232) was discovered.
3NF is relatively weak compared to 2NF. Hard to approach and find evidence
for 3NF experimentally.
3NF is relatively weak compared to 2NF. Hard to approach and find evidence
for 3NF experimentally.
2- Exchange 3NF Model Tucson-Melbourne (TM) Urbana IX Brazil Texas Ruhr Pot.
Pieper et al. Phys. Rev. C 64, 014001(2001)
First Indication of 3NF in 3H (A=3 Nuclei) Exp. v.s. Faddeev calc.Exp. v.s. Faddeev calc. B.E. (Exp.)B.E. (Exp.) -- B.E.(Faddev Calc.) B.E.(Faddev Calc.) = 0.5 – 1 MeV= 0.5 – 1 MeV
A few methods are applied to descriptions of A>4 Nuclei
Green’s Function Monte Carlo Green’s Function Monte Carlo Ab InitioAb Initio No-Core Shell Model No-Core Shell Model
etc…well reproduce B.E. of light nucleiwell reproduce B.E. of light nuclei
3NF Effects in Nuclei3NF Effects in Nuclei
Better understanding of 3NF is one key element to describe Nuclear Better understanding of 3NF is one key element to describe Nuclear Structure.Structure. How to constrain the properties of 3NF ?How to constrain the properties of 3NF ?To study dynamical aspects of 3NF, Spin and Momentum To study dynamical aspects of 3NF, Spin and Momentum
dependences,dependences,Few Nucleon (3N,4N) Scattering is attractive.Few Nucleon (3N,4N) Scattering is attractive.
To study dynamical aspects of 3NF, Spin and Momentum To study dynamical aspects of 3NF, Spin and Momentum dependences,dependences,
Few Nucleon (3N,4N) Scattering is attractive.Few Nucleon (3N,4N) Scattering is attractive.
GFMC
Comparing the Faddeev Calculations based on 2NF (e.g. CDBonn, AV18, Nijm I, II)
Cross Section forCross Section for d-p d-p Elastic Scattering Elastic Scattering at Intermediate Energiesat Intermediate Energies
Nd elastic scattering at intermediate energies (E/A ~ 100 MeV ) is a good probe to study 3NFs.
Nd elastic scattering at intermediate energies (E/A ~ 100 MeV ) is a good probe to study 3NFs.
- Discrepancy in the Cross Section Minimum → 3NF Effect!
K. Sekiguchi et al.Phys. Rev. C 65, 034003 (2002)
d-pd-p
N-d Elastic Scattering Data at 70-400 MeV/Aon the Market
Data mainly came from Data mainly came from RIKEN, RCNP, KVI, IUCF .RIKEN, RCNP, KVI, IUCF .
N-d Elastic Scattering Data at 70-400 MeV/Aon the Market
)(,,,, ' py
yxzxxyy
dy APAAAA
RIKEN
d-p Elastic Measurement at 70,100, and 135 MeV/A
Observables :
'''' ,,, yxz
yyy
yxx
yy KKKK– d to p polarization transfer
RIKEN Accelerator Research Facility (RARF)Spin symmetry axis of polarized d beams is freely controlled.
Polarized Ion Sourcevector & tensor d
Beam Line PolarimeterBy d+p Elastic Scattering
E ×B Spin Rotator
Spin axis is controlled by Spin Rotator prior to acceleration.
Single-turn extraction feature of RARF maintain the polarization amplitudes Beam polarizations : 60-80%
Spin axis is controlled by Spin Rotator prior to acceleration.
Single-turn extraction feature of RARF maintain the polarization amplitudes Beam polarizations : 60-80%
Focal Plane PolarimeterDPOL
RIKEN Magnetic Spectrograph SMART
SMART: Swinger and Magnetic Analyzer with Rotator and Twister
d
Swinger
Focal Plane
TargetCH2 / Liq.H2
List of the CalculationsBy Bochum-Cracow-KIT Group
NN Forces OnlyNN Interactions : CDBonn, AV18, Nijmegen I, II, & 93
NN + Tucson Melbourne (TM) 3NFNN Interactions : CDBonn, AV18, Nijmegen I, II, & 93
NN + TM99 3NF - closer to chiral symmetryNN Interactions : CDBonn, AV18, Nijimegen I,II
NN + Urbana IX 3NFNN Interactions : AV18
By Hannover Group NN with ( ) & w/o ( ) -isobar Excitations
NN Interactions : CDBonn
Comparison of the Data with the Faddeev Calculations
Summary of Comparison : Results for d-p Elastic Scattering at 70-135MeV/A
Discrepancies between the data and the calculations based on 2NF Discrepancies between the data and the calculations based on 2NF onlyonly Angular range : Clearly seen in the Cross Section Minimum
Energy dependence : Large as an Energy Increases
d/d : good agreement 3NFs are clearly needed.
Spin Observables : TM99/ Urbana IX does better job for Ay
p & T20 Requirement of chiral symmetry
Vector Pol. (Ayp & iT11 ) : good agreement
Tensor Pol. ( T20 , T21 , T22 ) : T20 & T21 : moderate agreement T22 : Chaotic Defects of 3NF
Higher order pol. (pol. transfer) : moderate agreementDirections are O.K, but sizes are not enough for Ky
y’ & Kxzy’.
When the When the 22-exchange 3NFs-exchange 3NFs are included … are included …
What are we missing?What are we missing?
Further ingredients of 3NF
Treatment of Relativistic EffectNew Nuclear Potential
Chiral Effective Field Theory etc…
Systematic Exp. Study of Few-Nucleon (3N-, 4N-) ScatteringSystematic Exp. Study of Few-Nucleon (3N-, 4N-) ScatteringSpin ObservablesSpin ObservablesEnergy DependenceEnergy DependenceSolid Base to Test TheorySolid Base to Test Theory
and exchange 3NF many -contributions with -rings
e.g. 3π-rings with -isobar excitations (Illinois Model)
- Link to QCD - Link to QCD - Nuclear forces (2NF, 3NF, … ) Nuclear forces (2NF, 3NF, … ) and currents are derived in a consistent way.and currents are derived in a consistent way.
Three Nucleon Force Study Three Nucleon Force Study viavia Few Nucleon Scattering at RIBF with pol d. beams Few Nucleon Scattering at RIBF with pol d. beams
up to near up to near threshold energy threshold energy
E/AE/A ≤ ≤ 350 MeV (350 MeV (EEdd ≤ 700 MeV≤ 700 MeV))
- 3NF effects are most strongly enhanced.- Max. energy where the state of the art Faddeev calc. based on NN forces are applicable. Nail down the spin parts of 3NFNail down the spin parts of 3NF
pol. pol. dd beams at RIBF : beams at RIBF : E/AE/A = 250 – 440 MeV = 250 – 440 MeV
Beam Line Polarimeter
dp elastic/breakup Measurement
SAMURAIdp elastic & radiative capture Measurement
PIS-AVF-RRC-SRC – then,PIS-AVF-RRC-SRC – then, Where?Where?
Polarized Ion Sourcevector & tensor pol. d
N-dN-d Elastic Scattering Data at 70-400 Elastic Scattering Data at 70-400 MeV/AMeV/Aon the Marketon the Market
at RIBFat RIBFat RARFat RARF
FinallyA new microscope “Few-N Scattering-at-intermediate-energies” has been set for exploring 3NFs.The 1st step is the Nd elastic scattering.Cross section shows the clear signature of 3NFs.
Spin observables have started showing their ability but not fully yet.
Future Key Elements : - Precise Data Set for Few Nucleon Scattering
- Chiral Effective Field Theory- Relativistic Effect- Further Ingredients of 3NF based on meson-exchange picture
The new microscope will lead us to clear understanding of 3NFs but also allow us to step into a further process.
Experiments were carried out under the collaboration of
RIKENK. Sekiguchi, N. Sakamoto, T. Ohnishi
University of TokyoH. Sakai, T. Uesaka, K. Yako, T. Kawabata, K. Suda, S. Sakoda,
Y. Maeda, H. Kato, M. Hatano, T. Saito, N. Uchigashima, H. Kuboki,M. Sasano, S. Satoshi, Y. Sasamoyoto, Y. Takahashi
RCNP, Osaka UniversityH. Okamura, A.Tamii,
Tokyo Institute of TechnologyY. Satou
Kyushu UniversityT. Wakasa
KVIN. Kalantar, K. ErmischSaitama UniversityJ. Nishikawa, K. Itoh